EFFECTS OF CPPU AND CoSO 4 ON POSTHARVEST QUALITY OF MANGOSTEEN FRUIT (Garcinia mangostana L.) DURING STORAGE CHEA SINATH

Transcription

1 EFFECTS OF CPPU AND CoSO 4 ON POSTHARVEST QUALITY OF MANGOSTEEN FRUIT (Garcinia mangostana L.) DURING STORAGE CHEA SINATH GRADUATE SCHOOL BOGOR AGRICULTURAL UNIVERSITY BOGOR 2010

2 DECLARATION I declare that this thesis titled Effects of CPPU and CoSO 4 on postharvest quality of mangosteen fruit (Garcinia mangostana L.) during storage. was entirely completed by myself with resourceful help from the Department of Agronomy and Horticulture, Bogor Agricultural University. Information and quotes which were sourced from journals and books have been acknowledged and mentioned where in the thesis they appear. All complete references are given at the end of the paper. Bogor, September 2010 Chea Sinath ID: A

3 ABSTRACT CHEA SINATH. A Effects of CPPU and CoSO 4 on Postharvest Quality of Mangosteen Fruit (Garcinia mangostana L.) during Storage. (Under supervision of ROEDHY POERWANTO, DARDA EFENDI, and SUTRISNO) Mangosteen (Garcinia mangostana L.) fruit is one of the most delicious tropical fruits, known as queen of tropical fruit with short shelf life during storage. The research objective was to study the effects of CPPU and CoSO 4 on postharvest quality and physiological changes of mangosteen fruit during storage. The experimental design was arranged in a completely randomized block design (CRBD) with two factors, i.e., cobalt sulphate and CPPU. Postharvest treatment with CPPU was found to be effective to promote lightness of mangosteen fruit at day 4 and day 6, while CoSO 4 tended to accelerate the darkening in both fruit and sepal. The resistance of mangosteen fruit pericarp was considered as low (less than 2 kgf/cm 2 ), representing that fruit were still easily to be opened during 30 days of storage. CPPU and CoSO 4 were less effective in inhibiting fruit hardening. Titratable acidity was significantly reduced in CPPU-treated fruit at the end of storage, while total soluble solids were not clearly affected by the treatment. TSS/TA ratio was significantly higher in fruit treated with CPPU at the end of storage. Respiration rate of mangosteen fruit was low and remained constant with prolonged storage period. CPPU and/or CoSO 4 could considerably decrease the respiration rate, but less effective in inhibiting ethylene production during storage at 14 o C-16 o C (78%-96% RH). Keywords: Fruit resistance, prolonged storage, postharvest treatment, respiration rate, ethylene production.

4 ABSTRAK CHEA SINATH. A Pengaruh CPPU dan CoSO 4 terhadap Kualitas Pascapanen Buah Manggis (Garcinia mangostana L.) selama Penyimpanan. (Dibimbing oleh ROEDHY POERWANTO, DARDA EFENDI, dan SUTRISNO) Buah manggis (Garcinia mangostana L.) merupakan salah satu buah tropis yang paling lezat, yang dikenal sebagai "queen of tropical fruit" dengan masa simpan rendah selama penyimpanan. Tujuan penelitian ini adalah untuk mempelajari pengaruh CPPU dan CoSO 4 terhadap kualitas pascapanen dan perubahan fisiologis buah manggis selama penyimpanan. Rancangan percobaan menggunakan rancangan acak kelompok lengkap (RAKL) dengan dua faktor, yaitu, kobalt sulfat dan CPPU. Perlakuan pascapanen dengan CPPU ditemukan efektif untuk mempromosikan kecerahan buah manggis pada hari ke 4 dan 6, sedangkan CoSO 4 cenderung mempercepat gelap baik pada buah atau sepal. Resistensi pericarp buah manggis dianggap rendah (kurang dari 2 kgf/cm 2 ), menunjukkan bahwa buah masih mudah untuk dibuka selama 30 hari penyimpanan. CPPU dan CoSO 4 kurang efektif menghambat pengerasan buah. Asam tertitrasi berkurang secara signifikan dalam buah pada perlakuan degnan CPPU di akhir penyimpanan, sedangkan total padatan terlarut tidak jelas terpengaruh oleh pelakuan. Rasio PTT/AT secara signifikan lebih tinggi dalam buah yang diberi perlakuan dengan CPPU di akhir penyimpanan. Laju respirasi buah manggis masih rendah dan tetap konstan dengan periode penyimpanan yang lama. CPPU dan / atau CoSO 4 dapat menurunkan laju respirasi, tetapi kurang efektif dalam menghambat produksi etilen selama penyimpanan pada 14 o C-16 o C (78% -96% RH). Kata kunci: Resistensi pericarp buah, masa simpan, perlakuan pascapanen, laju respirasi, produksi etilen.

5 SUMMARY CHEA SINATH. A Effects of CPPU and CoSO 4 on Postharvest Quality of Mangosteen Fruit (Garcinia mangostana L.) during Storage. (Under supervision of ROEDHY POERWANTO, DARDA EFENDI, and SUTRISNO) Physical, chemical and physiological changes during storage are common phenomena occurring in all commodities. Postharvest quality is strongly associated with those changes and depends heavily on commodity characteristics, preharvest factor, postharvest treatment and storage condition. Physiochemical changes of climacteric products during storage are substantially triggered by its respiratory rate and ethylene production. Since mangosteen fruit is climacteric fruit, postharvest attributes may be related to climacteric respiration and ethylene production. Postharvest application of substances that can suppress respiration and ethylene production may help prolong shelf-life of mangosteen fruit during storage. The objective of the research was to study the effects of CPPU and CoSO 4 on postharvest quality and physiological changes of mangosteen fruit during storage. The research was done at Postharvest Laboratory, Faculty of Agriculture, Laboratory of Food and Agricultural Product Process Engineering, Laboratory of Environmental and Agricultural Building, Faculty of Agricultural Technology, Bogor Agricultural University (IPB), starting from February to May The research was divided into two stages. The first experiment covered physical and chemical changes of mangosteen fruit treated with CPPU and CoSO 4 during storage, while the second one involved the study of physiological and its relation to color development of mangosteen fruit treated with CPPU and CoSO 4 during storage. The experimental design was arranged in a completely randomized block design with 2 factors and 3 replications. The first factor was cobalt sulphate (CoSO 4 ) at four concentrations 0, 500, 1000, and 2000 ppm, while the second one was CPPU at four concentrations 0, 10, 20, and 30 ppm. The combination of the above factors provided 16 treatments with 48 experimental units. Each experimental unit comprised 40 mangosteen fruit. For the second experiment, the design was as in the first experiment, but only cobalt sulphate at 0, 2000 ppm, and CPPU at 0, 30 ppm were used with 5 mangosteen fruit per experimental unit. The fruits used in the experiment were harvested at stage 1 (light greenish yellow with 5-50% scattered spots)

6 on the same day and were of similar sizes. The harvested fruit were transported at night to laboratory. In the following morning, the fruit were sorted, and washed with tap water to remove the dust. After washing, the fruit were air dried, and then treated with solution of fungicide TBZ 1 ppm for 30 seconds and air dried. Following fungicide application, airdried fruit were dipped in the solution of CoSO 4 and CPPU for 30 seconds according to its concentrations used in the treatments. To facilitate the absorption of the solution by fruit, tween20 (1%) was added. After application, treated fruits were air dried, then stored at o C (76-96% RH). Fruit resistance (FR), pericarp water content (PWC), fruit and sepal color, weight loss (WL), total soluble solids (TSS), and titratable acidity (TA) were measured every two days in the experiment one. Respiration rate was measured every 3 hours on the first day, followed by 6 hours in the second day, 12 hours, and 24 hours in the following days up to day 27. Ethylene production was measured every day up to storage day 12. Analysis of variance was done using SPSS statistics 17.0 and treatment means were compared using Duncan s Multiple Range Test (DMRT) at P<0.05. The results showed that Postharvest treatment with CPPU was found to be effective to promote lightness of mangosteen fruit at day 4 and day 6, while CoSO 4 tended to accelerate the darkening in both fruit and sepal. The resistance of mangosteen fruit was considered as low (less than 2 kgf/cm 2 ), representing that fruit were still easily to be opened during 30 days of storage. CPPU and CoSO 4 were less effective in inhibiting fruit hardening. Titratable acidity was significantly reduced in CPPU-treated fruit at the end of storage, while total soluble solids were not clearly affected by the treatment. TSS/TA ratio was significantly higher in fruit treated with CPPU at the end of storage. Respiration rate of mangosteen fruit was low and remained constant with prolonged storage period. CPPU and/or CoSO 4 could considerably decrease the respiration rate, but less effective in inhibiting ethylene production during storage at o C (78%-96% RH). In conclusion, Postharvest treatments of either CPPU or CoSO 4 were found to have low effectiveness on the component of postharvest quality of mangosteen fruit although sporadic significances were observed among observed times. Mangosteen fruit is a climacteric fruit with high ethylene production after harvest. However, no clear peak of respiration was observed during cold storage. Fruit color changes were closely associated with ethylene production. Keywords: Climacteric fruit, shelf life, color development, ethylene production, respiration rate.

7 Copyright of IPB, year 2010 Copyright reserved 1. Forbidden to quote part or all of these writings without including or mentioning the source. a. Be cited only for educational purposes, research, writing papers, drafting reports, writing criticism or review an issue; b. Quotation must not harm the affairs of IPB. 2. Prohibit publication and reproduction of part or all of the paper in any form without permission of IPB or the writer.

8 EFFECTS OF CPPU AND CoSO 4 ON POSTHARVEST QUALITY OF MANGOSTEEN FRUIT (Garcinia mangostana L.) DURING STORAGE CHEA SINATH A Thesis As Partial fulfillment of the Requirement to obtain Master of Science Degree in Agronomy and Horticulture GRADUATE SCHOOL BOGOR AGRICULTURAL UNIVERSITY BOGOR 2010

9 Title Name : Effects of CPPU and CoSO 4 on Postharvest Quality of Mangosteen Fruit (Garcinia mangostana L.) during Storage. : Chea Sinath Registration Number : A Major : Master of Science in Agronomy and Horticulture Approved: Advisory Committee Prof. Dr. Ir. Roedhy Poerwanto, M.Sc (Chairman) Dr. Ir. Darda Efendi, M.Si (Member) Dr. Ir. Sutrisno. M.Agr (Member) Agreed: Graduate Coordinator of Major Dean of Graduate School Dr. Ir. Munif Ghulamahdi, MS Prof. Dr. Ir. Khairil Anwar Notodiputro, MS Examination Date: 2 nd of September, 2010 Date of Completing studies:

10 ACKNOWLEDGEMENT My study and thesis research would not have been accomplished without the help of many people. Special thanks to Prof. Dr. Ir. Roedhy Poerwanto, MSc, Dr. Ir. Darda Efendi, MSi, and Dr. Ir. Sutrisno, M.Agr, as supervisory committee, for all of guidance and encouragement as well as invaluable academic advices for the whole period of my study and research at IPB. Special thanks also are to be given to the Department of Agronomy and Horticulture and Department of Agricultural Technology for the full support given to enable the successful completion of this research. I am very grateful to all the invaluable lecturing staff as well as lab and technical staff of Agronomy and Horticulture Department who have imparted knowledge and help. Extended thanks are expressed to all fellow students of Agronomy and Horticulture Department and KNB Scholarship. Of these fellows, I would like to express my deepest thanks to close friends Sanou Faye, Dahono and Herman who always providing a helping hand and good advices. I wholeheartedly thank to research team of mangosteen fruit postharvest such as Ismadi, Mesil, and Hatifah, who made my master research a great experience of team working. Further, I am highly indebted to my affectionate parents, brother (Na Bunnan), sisters (Na Dany, Na Chantha, Na Chan Thu, Chea Veasna, Chea Ratana and Chea Phalla) and other family members who always inspire and encourage me for higher education, and finally to Miss Bao Lian who contributes immensely in providing psychological supports and good constructed advice during busy time of my study and research. The research was financially supported by Hibah Tim Pasca Sarjana, and additional funding was provided through my study sponsor-dikti under Developing Countries Partnership Program. Bogor Agricultural University, September 2010 MSc. Agronomy and Horticulture

11 BIOGRAPHY Chea Sinath was born on the 2 nd of March, 1981 in Takeo province to Mr Na Cheam and Mrs Sok Kimngy from Cambodia. Chea Sinath was born the fifth of eight children. In 2001, he finished Senior High School from Heng Somrin Prey Lovea High School and continued with Bachelors Degree study in Agronomy and graduated in August 2005, from the Royal University of Agriculture. After Bachelors level, he had worked for Cambodian Agricultural Research and Development Institute (CARDI) as research assistant in Agronomy and Farming systems office for a year. In 2006, he continued with higher teacher training (Bachelor +1) at National Institute of Education and started teaching at Prek Leap High School located in Phnom Penh since In 2008, he was awarded by the Indonesian Government to do Masters Degree in Bogor Agricultural University, majoring in Agronomy and Horticulture under the Developing Countries Partnership Program (KNB Kemitraan Negara Berkembang) with official permission from the Cambodian Ministry of Education, Youth and Sports for a period of Master Degree study program in Indonesia.

12 TABLE OF CONTENTS LIST OF TABLES... LIST OF FIGURES... LIST OF APPENDICES... vii viii ix I. INTRODUCTION Background Objective Hypotheses... 2 II. LITERATURE REVIEW 2.1. Mangosteen Fruit Development and Maturity Indices Mangosteen Fruit Quality and Color Development Causes of Mangosteen Fruit Hardening Fruit Ripening and Senescence Ethylene Biosynthesis and its Physiological Effects Ethylene Action and Methods for Inhibiting Ethylene Responses Cytokinin and its Physiological Effects Cobalt Sulphate (CoSO 4 ) and its Effects III. MATERIAL AND METHODS 3.1. Time and Place Plant Material and Treatment Observed Variables Physical Attributes Fruit Resistance Pericarp Water Content Weight Loss Fruit and Sepal Color Chemical Attributes Total Soluble Solids Titratable acidity Physiological Variables Respiration Rate Ethylene Production Statistical Analysis IV. RESULTS AND DISCUSSION 4.1. Physical Changes of Mangosteen Fruit during Storage Fruit Resistance Pericarp Water Content Weight Loss Fruit Color... 22

13 Lightness a/b ratio Hue angle (h o ) Sepal Color Lightness a/b ratio and Hue angle Visual Observation Chemical Changes of Mangosteen Fruit during Storage Total Soluble Solids ( o Brix) Titratable Acidity (%) TSS/TA ratio Physiological Changes and its Relation to Color Development Respiration Rate of Mangosteen Fruit Ethylene Production of Mangosteen Fruit Lightness and Hue angle of Mangosteen Fruit V. CONCLUSIONS AND SUGGESTION REFERENCES APPENDICES... 47

14 LIST OF TABLES Page 1 Harveste mangosteen maturity indices developed in Malaysia Effects of CPPU and CoSO 4 interaction on pericarp water content (%) of mangosteen fruit during storage at day Effects of CPPU and CoSO 4 interaction on a/b ratio of sepal of mangosteen fruit during storage at day 22 and day Effects of CPPU and CoSO 4 interaction on hue angle of sepal of mangosteen fruit during storage at day 22 and day Effects of CPPU and CoSO 4 interaction on TSS &TA ratio of mangosteen fruit during storage at day Effects of CPPU and CoSO 4 interaction on respiration rate of mangosteen fruit during storage vii

15 LIST OF FIGURES Page 1 The ethylene synthesis pathway Resistance of mangosteen fruit treated with CPPU during storage Resistance of mangosteen fruit treated with CoSO 4 during storage Weight loss of mangosteen fruit treated with CPPU during storage Weight loss of mangosteen fruit treated with CoSO 4 during storage Changes in skin lightness of mangosteen fruit treated with CPPU during storage Changes in skin lightness of mangosteen fruit treated with CoSO4 during storage Changes in skin color (a/b) of mangosteen fruit treated with CPPU during storage Changes in skin color (a/b) of mangosteen fruit treated with CoSO 4 during storage Changes in skin color (h o ) of mangosteen fruit treated with CPPU during storage Changes in skin color (h o ) of mangosteen fruit treated with CoSO 4 during storage Changes in sepal color (L) of mangosteen fruit treated with CPPU during storage Changes in sepal color (L) of mangosteen fruit treated with CoSO 4 during storage Changes in sepal color (a/b) of mangosteen fruit treated with CPPU during storage Changes in sepal color (a/b) of mangosteen fruit treated with CoSO 4 during storage Changes in sepal color (h o ) of mangosteen fruit treated with CPPU during storage Changes in sepal color (h o ) of mangosteen fruit treated with CoSO 4 during storage viii

16 18 Changes in total soluble solids of mangosteen fruit treated with CPPU during storage Changes in total soluble solids of mangosteen fruit treated with CoSO 4 during storage Changes in titratable acidity of mangosteen fruit treated with CPPU during storage Changes in titratable acidity of mangosteen fruit treated with CoSO 4 during storage Changes in TSS/TA of mangosteen fruit treated with CPPU during storage Changes in TSS/TA of mangosteen fruit treated with CoSO 4 during storage Respiration rate of mangosteen fruit treated with CPPU and CoSO 4 during storage Ethylene production of mangosteen fruit treated with CPPU and CoSO 4 during storage Changes in lightness of mangosteen fruit treated with CPPU and CoSO 4 during storage Changes in Hue angle (h o ) of mangosteen fruit treated with CPPU and CoSO 4 during storage ix

17 LIST OF APPENDICES Page 1 Effects of CPPU and CoSO 4 on fruit resistance (kgf/cm 2 ) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on pericarp water content (%) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on weight loss (%) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on lightness (L) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on a value (red-green) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on b value (yellow-blue) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on a/b value of mangosteen fruit during storage Effects of CPPU and CoSO 4 on hue angle of mangosteen fruit during storage Effects of CPPU and CoSO 4 on lightness (L) of sepal of mangosteen fruit during storage Effects of CPPU and CoSO 4 on a value (red-green) of sepal of mangosteen fruit during storage Effects of CPPU and CoSO 4 on b value (yellow-blue) of sepal of mangosteen fruit during storage Effects of CPPU and CoSO 4 on a/b ratio of sepal of mangosteen fruit during storage Effects of CPPU and CoSO 4 on hue angle of sepal of mangosteen fruit during storage Effects of CPPU and CoSO 4 on total soluble solids ( o Brix) of mangosteen fruit during storage x

18 15 Effects of CPPU and CoSO 4 on titratable acidity (%) of mangosteen fruit during storage Effects of CPPU and CoSO 4 on TSS &TA ratio of mangosteen fruit during storage Changes in respiration rate of mangosteen furit treated with CPPU and CoSO 4 during storage ` Ethylene production of mangosteen fruit treated with CPPU and CoSO 4 during storage Images of mangosteen fruit treated with CPPU and CoSO 4 during storage xi

19 I. INTRODUCTION 1.1 Background Indonesia is one of the major mangosteen producers in Southeast Asia. The production of mangosteen in 2007 was 112,722 ton with average yield of 9.42 ton/ha. Indonesia exports fresh mangosteen to China (including Hong Kong and Taiwan), Japan, Singapore, the Netherlands, France and Saudi Arabia (Osman and Milan, 2006). The volume of export was 9,093,245 kg in 2007 and increased to 9,465,665 kg in 2008, which valued at USD 4,951,442 and USD 5,832,534 in 2007 and 2008, respectively (Ditjen Hortikulura, 2009). Indonesian mangosteen export is only 8.06% from the total production 112,722 ton in Many issues are involved in low fruit quality and have resulted in a barrier for exports and low export value, namely (i) gamboge, a physiological disorder evident by exudating latex onto the fruit surface and aril rendering the fruit unsuitable for eating, (ii) brown spot (burik) on the fruit skin, and (iii) short shelf life of mangosteen fruits (pericarp hardening, color changes to dark blackish purple, and fruit calyx turns brown within a few day). Generally, the fruit will soften within a few days after harvested. On the contrary, mangosteen fruit hardens and causes difficulty in opening after prolonged storage. Mechanical injury of fruit during storage and handling of mangosteen often causes fruit hardening (Kader, 2003). A drop of 10 cm can cause slight pericarp damage, indicated as hardening at the point of impact within 24 h. Higher drops cause significantly greater damage and often lead to downgrading of the fruit (Tongdee and Suwanagul, 1989; Ketsa and Atantee, 1998). Azhar (2007) reported that optimal temperature for endurance of skin color and calyx was 10 o C, and temperature storage less than 10 C (50 o F) leads to rapid hardening and darkening of pericarp when fruit are returned to ambient temperature (Uthairatanakij and Ketsa, 1995). Storage at 4 C (39.2 F) or 8 C (46.4 F) can lead to significant hardening of the pericarp (Augustin and Azudin, 1986), although the flesh may still be acceptable after 44 days. However, storage of mangosteen fruit at temperature above 15 o C can also cause hardening and result in opening difficulty. Anggraini (2008) found that chitosan coating

20 2 treatment was more effective to inhibit pericarp hardening, and shelf-life of mangosteen fruit could be kept as long as 20 days after treatment (Ekaputri, 2009). Changes of fruit color are one of maturity parameter. Inayati (2009) found that fruits coated with wax, chitosan and coconut oil suspension could inhibit fruit hardening from 14 days to 20 days. In climacteric fruits, ethylene production at the onset of ripening controls the changes of color, aroma, texture, flavour, and other biochemical and physical attributes (Lelievre et al., 1997). Since mangosteen fruit is climacteric fruit (Qanitah, 2004), postharvest quality changes may be related to climacteric respiration and ethylene production. Co 2+ is a potent inhibitor of ethylene biosynthesis. Application of cobalt sulphate is expected to change the climacteric respiration of mangosteen during storage. Williams and Golden (2002) found that the enzyme ACC was inhibited by Cobalt sulphate (CoSO 4 ). Forchlorfenuron (CPPU) is a type of synthetic cytokinins, which is responsible for the maintenance of chlorophyll, protein, and RNA levels. Although CPPU has been found to be effective in improving postharvest quality of many fruits when applied at preharvest, its direct postharvest application has not yet been reported. Therefore, research on postharvest application of CPPU and CoSO 4 needs to be conducted. 1.2 Research Objective The objective of the research was to study the effects of CPPU and CoSO 4 on postharvest quality and physiological changes of mangosteen fruit during storage. 1.3 Research Hypotheses 1. Ethylene production can be decreased by application of CoSO 4 because CoSO 4 can inhibit ethylene biosynthesis. This has resulted in better shelflife of mangosteen fruit. 2. Application of CPPU can delay changes of sepal color because it can delay chlorophyll degradation. 3. Combination of CPPU and CoSO 4 can extend shelf-life of mangosteen fruit longer than individual application.

21 II. LITERATURE REVIEW 2.1 Mangosteen Fruit Development and Maturity Indices Mangosteen fruits are produced singly at the end of the branchlets, and usually do not mature and ripen uniformly. The tree will bear coexisting generations of fruit, resulting from successive generations of flowers. Therefore, not all the fruits will reach maturity or ripen at the same time. Mangosteen fruits take 5 to 6 months to mature from fruit set. Initially, fruit growth is dominated by the pericarp, with aril dry matter not increasing until 20 days from anthesis and then continuing throughout the fruit development. At 13 weeks the fruit shows the highest percentages of pulp, rind, sugar and acid: 29.37%, 69.14%, 18% and 0.49%, respectively (Kanchanapom and Kanchanapom, 1998). During ripening, a thick, clear green cortex changes to dark purple or red purple. Enclosed by the rind are 4-8 edible white segments. The flavor is slightly acidic, but sweet (Nakasone et al., 1998). At present, there is no standard or uniform maturity index that is universally used. Countries such as Malaysia, Thailand and Australia have developed their own maturity indices for harvesting to meet various marketing purposes. For harvesting maturity indices used by growers in Australia, fruit harvested at stage 1 with pale yellow-green color, ph 3.9, rind thickness 9.0 mm, Brix%<12, and firmness index 7.9, and stage 2 with botchy pink color, ph 3.3, rind thickness 7.7mm, Brix%<14 and firmness index 6 are not acceptable. Fruit harvested at stage 3 with pinkish red, ph 3.2, rind thickness 7.4mm, Brix%>16, and firmness index =5; fruit harvested at stage 4 with maroon-red, ph 3.2, rind thickness 7.2mm, Brix%>16, firmness index 5; and stage 5 with maroon-violet, ph 3.2, rind thickness 7.0mm, Brix%>16, firmness index=5 are acceptable. Fruit harvested at stage 6 with violet-black, ph 3.6, rind thickness 6.8mm, Brix%<14, and firmness index=5 is also unacceptable. However, Tongdee and Suwanagul (1989) reported that fruits are at the edible, ripe stage when the skin has darkened to a reddish purple, no latex remains in the skin, and the flesh segments separate easily from the skin, and soluble solids content ranges from 17 to 20% and titratable acidity ranges from 0.7 to 0.8 (ph = 4.5 to 5.0) (Kader, 2002).

22 4 Table 1. Mangosteen Maturity Indices Developed in Malaysia Stages Skin Color changes Stuitability This fruit is yellowish green with red patches. At this stage the pulp and the rind are not separable The fruit is pale yellow or green, with pink spots scattered over the part of the skin. The fruit has the light yellow- pink color with pink patches scattered all over the skin. The skin and pulp can be separated. The fruit is evenly pink in color. The patches of pink seen in stage 2 enlarge and merge so as to become congruent. The pulp can be separated from the rind. The fruit color is now red brownish red. Separation of the pulp and rind is easy. The fruit, if harvested at this stage would develop a poor flavor The quality of the pulp is still low. Fruit harvested at this stage will give a good quality flavor. Fruit at this stage is suitable for export. The fruit is also suitable for export. Fruit and half fruit showing color changes 5 6 The fruit is red-purple in color. No gum is presented in the rind. The pulp and rind are readily separated. The fruit is now purple, dark purple or black. The rind contains no gum. Pulp and rind are readily separated. The fruit is suitable for consumption. The fruit is suitable for consumption. Sources: MOA (2002)

23 5 2.2 Mangosteen Fruit Quality and Color Development The quality of mangosteen (Garcinia mangostana L.) fruit is measured not only by external factors such as color, shape, size, skin blemishes, latex staining and insect damage, but also by internal factors such as translucent flesh, yellow gummy latex and hardening pericarp which are also very important for consumer acceptance (Teerachaichayut et al., 2006). Fruit color is a major criterion used to judge maturity and for grading of mangosteen fruit. The fruit are usually harvested at different stages according to colour, from light greenish yellow with scattered pink spots to dark purple. After harvest, the purple color continues to develop very quickly. For high fruit quality, the minimum harvest color stage is that of distinct irregular, pink red spots over the whole fruit. If fruit are harvested with a light greenish yellow with scattered pink spots, the fruit do not ripen to full flavor (Tongdee and Suwanagul, 1989; Paull and Ketsa, 2004). ` The color of mangosteen (Garcinia mangostana L.) fruit changes from green to purple black after harvest as the fruit ripens, and is used as a quality guide for growers and consumers. During the postharvest period, hue angle values and pericarp firmness decreased significantly, while soluble solids contents increased. Anthocyanin contents in the outer pericarp were higher than in the inner pericarp and increased to a maximum at the final color stage (Palapol et al., 2009). Commercial production has been limited by slow growth, long juvenile periods of years and short shelf-life of fruits when mature (Wiebel et al., 1992). Keeping quality of mangosteen fruits is longer compared to other tropical fruits. Long storage of fruits leads to hardening of pericarp and opening of fruit become difficult (Radha et al., 2007). Palapol et al. (2009) indicated that fruit harvested at stage 1 developed rapidly to the purple black stage (stage 6) within 9 days with color development from stage 5 to stage 6 being slower than other stages. During color development, the a * /b * value increased slightly from stage 1 to stage 3, and then increase sharply to stage 6. The increase in the a * /b * values correlated well with color development. When fruit at the six different stages of maturity were harvested and kept at 25 o C, each stage fully developed to the purple black stage 6. No matter at what stage the fruit were harvested, they all ripened, and no significant differences in sensory evaluation and fruit quality,

24 6 including hue angle values, firmness, soluble solids content (SSC) and titratable acid (TA), when the fruit were accessed at stage 6 (Palapol et al., 2009). Calyx freshness of mangosteen fruit strongly affects quality value during periods of storage. Fresh mangosteen fruit has green and fresh calyx, but the freshness becomes brown after a few days. Research conducted by Suryanti et al. (1999) showed that mangosteen fruit harvested at green and fresh peel with purple spots and calyx freshness could maintain its freshness for 6 days of storage. Optimum temperature for retention of peel and calyx color is 10 o C (Azhar, 2007). Ekaputri (2009) found that treatment of chitosan 1.5% could retain color of mangosteen peel and calyx. Beeswax 6% treatment and BAP 20 ppm could retain calyx color for 21 days after treatment, but it started wrinkling after 15 days of treatment (Pratiwi, 2008). Anggraeni (2008) reported that combination of 0.01 mm- thick plastic wrapping and chitosan coating 1.5%, and plastic wrapping with wax Britex gave a better effect on inhibiting changes of peel and calyx color for 30 days of storage at room temperature, and 35 days at temperature 15 o C. 2.3 Causes of Mangosteen Fruit Hardening Generally the fruit will soften during a few days after harvested, but mangosteen fruit become harden that causes difficulty in opening fruits for consumption. Mechanical injury of fruit during storage and handling of mangosteen often causes fruit hardening (Kader, 2003). A drop of 10 cm can cause slight pericarp damage, indicated as hardening at the point of impact within 24 h. Higher drops cause significantly greater damage and often lead to downgrading of the fruit (Tongdee and Suwanagul, 1989; Ketsa and Atantee, 1998). Storage temperature less than 10 C (50 o F) leads to rapid hardening and darkening of pericarp when fruit are returned to ambient temperature (Uthairatanakij and Ketsa, 1995). Storage at 4 C (39.2 F) or 8 C (46.4 F), can lead to significant hardening of the skin (Augustin and Azudin, 1986), although the flesh may still be acceptable after 44 days. Ideal storage temperature for mangosteen is 15 o C. Temperature above 15 o C mangosteen fruit hardens and results in opening difficulties.

25 7 Anggraini (2008) reported that chitosan-coated treatment gave better effects on inhibiting pericarp hardening change, while shelf-life of mangosteen fruit could be kept as long as 20 days after treatment (Ekaputri, 2009). Dangcham et al. (2008) found that when pericarp hardening occurred, pericarp firmness and lignin contents increased while total phenolics decreased and fruit at the red-brown and red-purple maturity stages stored at 6 o C had higher lignin contents than of those stored at 12 o C. Of the phenolic acids predominant in the hardened pericarp, p- coumaric acid declined whereas sinapic acid increased throughout the storage time. Application of low O 2 (0.25%) to red-purple fruit during storage at 6 o C (84% RH), or at room temperature (30 o C, 71.5% RH) following storage at 6 o C, did not reduce pericarp hardening and there were no significant differences in firmness, lignin and total free phenolics when compared with fruit in normal air conditions. The results also suggested that increase in pericarp firmness of mangosteen fruits results from induction of lignin synthesis, associated with an increase in phenylalanine ammonia (PAL) and peroxydase (POD) activity and gene expression. Recent research conducted by Palapol et al. (2009) showed that pericarp firmness of mangosteen fruit decreased from stage 1 to stage 6, 779.3, 201.3, 136.0, 98.4, 66.5 and 46.5 N, respectively when stored at temperature 25 o C. Increases in pericarp lignin contents are at least part of the reason for the tissue hardening. Bunsiri (2003) found that 3 hours after impact, lignin contents increased in the damaged pericarp Fruit Ripening and Senescence Ripening and senescence are the ultimate phases in the developmental events of fruits that result in the expression of the quality characteristics inherent to the fruit (Paliyath et al., 2008) and this phenomenon involves structural, biochemical, and molecular changes that in many cases bear the hallmarks of programmed cell death (Arora, 2008). Degradation of structural elements such as the cell wall and the plasma membrane results in a loss of compartmentalization of ions and metabolites, leading to the loss of tissue structure and ultimately homeostasis (Paliyath et al., 2008).

26 8 Fruit ripening is accompanied by a number of biochemical events, including changes in color, sugar, acidity, texture, and aroma volatiles that are crucial for the sensory quality. At the late stages of ripening, some senescence-related physiological changes occur that lead to membrane deterioration and cell death. All biochemical and physiological changes that take place during fruit ripening are driven by the coordinated expression of fruit ripening-related genes. These genes encode enzymes that participate directly in biochemical and physiological changes. They also encode regulatory proteins that participate in the signaling pathways, and in the transcriptional machinery that regulate gene expression and set in motion the ripening developmental program (Bouzayen et al., 2010). For the consumers and distributors, the process of ripening corresponds to those modifications that allow fruit to become edible and attractive for consumption (Bouzaye et al., 2010). Fruits have classically been categorized based upon their abilities to undergo a program of enhanced ethylene production and an associated increase in respiration rate at the onset of ripening. Fruits that undergo this transition are referred to as climacteric and include tomato, apple, peach, and banana, whereas fruits that do not produce elevated levels of ethylene are known as non-climacteric and include citrus, grape, and strawberry (Barry and Giovannoni, 2007). The relationship existing between the climacteric respiration and fruit ripening has been questioned following the discovery that ripening on the vine of a number of fruit may occur in the absence of any increase in respiration (Salveit 1993; Shellie and Salveit 1993). More recently, it has been reported that the presence or absence of a respiratory climacteric on the vine depends upon prevailing environmental conditions (Bower et al. 2002). These observations indicate that the respiratory climacteric is probably not an absolute trigger of the ripening process, but secondary and consequential to the process of ripening. An ethylene burst that precedes respiratory climacteric has been shown during the ripening of banana (Pathak et al. 2003). Senescence of leaves, flowers and fruits can be regulated by an array of external and internal factors. Many environmental stresses (such as extreme temperatures, drought, nutrient deficiency, insufficient light/shade or total darkness) and biological insults (such as pathogen infection) can induce

27 9 senescence. Internal factors influencing senescence include age, levels of plant hormones and other growth substances, and developmental processes such as reproductive growth (Gan, 2004). Ethylene plays a key role in promoting senescence of climacteric fruits and flowers although it is less effective in stimulating non-climacteric fruits and flowers to senesce. Other promotions of senescence process include sugar, jasmonic acid (JA), salicylic acid (SA), brassinosteroids (BRs), and abscisic acid (ABA), while cytokinins (CK), Polyamines (PAs), Auxin, Gibberellins are considered to delay senescence process (Gan, 2004) Ethylene Biosynthesis and its Physiological Effects Ethylene is synthesized by most tissues in response to stress. In particular, it is synthesized in tissues undergoing senescence or ripening (Davies, 2004). Chaves and Mello-Farias (2006) provide a thorough review of the ethylene synthesis pathway that the end of the ethylene synthesis pathway involves three enzymes to convert methionine into ethylene (Figure 1). Two of these enzymes are involved in the formation and oxidation of the immediate precursor of ethylene, 1-aminocyclopropane-1-carboxylic acid (ACC). ACC-synthase converts S-Adenosylmethionine (SAM) into ACC and is the rate-limiting step in the pathway. ACC-oxidase catalyzes the conversion of ACC to ethylene. The final conversion of ACC to ethylene is oxygen dependent (Kende, 1993). Ethylene is a plant hormone influencing plant processes such as the so called triple response, maintenance of the apical hook in seedlings, stimulation of defense responses in response to injury or diseases, release from dormancy, shoot and root growth and differentiation, adventitious root formation, leaf and fruit abscission, flower induction in some plants, induction of femaleness of dioecious flower, flower opening, flower and leaf senescence, fruit ripeing (Davies, 2004). Of particular economic importance is the role of ethylene as an inducer of fruit ripening (Bleecker and Kende, 2000). Through this action, it induces changes in certain plant organs, such as textural changes, color changes, and tissue degradation. Some of these changes may be desirable qualities associated with ripening; in other cases, it can bring damage or premature decay (Silva, 2008). In

28 10 climacteric fruits, ethylene is generally thought to be regulate fruit ripening by coordinating the expression of gene responsible for 1) enhancing a rise in the rate of respiration, 2) autocatalytic ethylene production, 3) chlorophyll degradation, 4) pigment synthesis (carotenoids and flavonoids), 5) conversion of starch to sugars, production of aroma volatiles, and 7) increase of activities of cell wall-degrading enzymes (pulp and peel softening), 8) changes in ph (Grey et al., 1992; Lelievre et al., 1997; Seymour et al., 1993). Kader (2002) recommended that respiration of mangosteen fruit kept at 20 o C should be 6-10ml CO 2 /kg/hr. Palapol et al. (2009) measured ethylene production of mangosteen fruit stored at temperature 25 o C and found that ethylene production at stage 1 increased linearly until stage 5 (dark purple) by 5 days, then decreased slightly after stage 5. Figure 1. The ethylene synthesis pathway (modified from Chaves and Mello- Farias, 2006).

29 Ethylene Action and Methods for Inhibiting Ethylene Responses Ethylene inhibitors reduce or eliminate the biological activity of ethylene.these compounds can be divided into two groups: inhibitors of ethylene biosynthesis and inhibitors of ethylene action. The first are substances that interact with the ethylene biosynthesis pathway through inhibition of key enzymes, ACC synthase, and ACC oxidase. The 1-aminoethoxyvinylglycine (AVG) and the amino-oxyacetic acid (AOA) are inhibitors of ethylene biosynthesis, while silver thiosulfate (STS), silver nitrate, and 1-methylcyclopropene (1-MCP) are inhibitors of ethylene action (Ferrante and Francini, 2008). Yang and Hoffman (1984) indicated that aminoethoxyvinylglycine (AVG) and aminoethoxycetic acid (AOA) disrupt ACC synthase, while cobalt (Co 2+ ) and α-aminois-butyric acid (AIBA) disrupt ACC oxidase. Blocking ethylene effects at the receptor level is more effective as it will protect against both endogenous and exogenous ethylenes (Serek and Reid, 1993). The silver ion (Ag + ) has proved to be a potent inhibitor of ethylene action in ornamentals. STS is generally applied as a pretreatment solution to cut flowers. The persistence and mobility of STS allows very short pulse treatments. In potted plants STS is applied as an aqueous spray. Beneficial effects of STS are reported for a great variety of cut flowers and potted plants. STS treatment prevents petal senescence induced by ethylene and prolongs the vase life (Arora, 2008). 1- Methylcyclopropene (1-MCP) has been reported to be a non-toxic antagonist of ethylene action (Sisler and Serek, 1997) that blocks the physiological action of ethylene (Sisler et al.,1996). Applications of 1-MCP to delay fruit ripening and extend the storage life have been extensively reported in both climacteric and nonclimacteric fruit (Watkins, 2006). The use of 1-MCP for harvested fruits and vegetables represents a revolutionary advance in postharvest science and practices. The gas works by attaching to a site (receptor) in fruit tissues that normally binds to ethylene. Binding of ethylene to these sites is how plant tissues perceive that ethylene is present in the environment. If ethylene binding is prevented, ethylene no longer promotes ripening and senescence (Huber et al., 2003).

30 Cytokinin and its Physiological Effects Cytokinins are derivatives characterized by an ability to induce cell division in tissue culture, and the most common cytokinin base in plants is zeatin. It is biosynthesized through the biochemical modification of adenine and transported from roots to shoots. The effects of cytokinins include cell division, morphogenesis, growth of lateral buds, leaf expansion, delay leaf senescence, enhancement of stomatal opening in some species, chloroplast development (accumulation of chlorophyll and conversion of ethioplasts into chloroplasts) (Davies, 2004). A synthetic cytokinin N 1 -(2-Chloro-4-pyridyl)- N 3 -phenylurea (CPPU) is known to be effective for enhancing fruit enlargement by stimulating cell division and/or cell expansion in many kinds of fruits including Actinidia deliciosa kiwifruit (Iwahori et al., 1988; Lewis et al., 1996; Cruz-Castillo et al., 2002). Jo et al. (2003) reported that a single application of CPPU at the concentration of 16 mg l days after pollination was effective for increasing the fruit size of a local selection. The effectiveness of CPPU application on fruit development of Actinidia deliciosa kiwifruit was largely influenced by the time of application and concentration (Cruz-Castillo et al., 1999). Antognozzi et al. (1996) found that spraying application of CPPU 20 ppm on Actinidia deliciosa (A. Chev.) fruitlets inside the canopy 2 weeks after full bloom influenced fruit growth soon after treatment and yield per vine were about 25% higher than the control. The chlorophyll content was higher in CPPU treated fruits. During storage, the differences in carbohydrate content disappeared and treated fruits performed as well as control ones, maintaining good quality for up to 6 months. Cruz-Castillo et al. (2002) reported that the cytokinin-active compound, N 1 -(2-chloro-4-pyridyl)- N 3 -phenylurea (CPPU), applied at different flowering dates, affected final Hayward kiwifruit size. Recent research conducted by Kim et al. (2006) showed that fruit size of hardy Kiwifruit was increased and fruit weight was doubled when CPPU was applied at concentration of 5-10 mg l -1 and at 10 days after petal fall (DAPF). Although a significant reduction in the concentrations of total soluble solids (TSS), titratable acids (TA) and ascorbic acid (AsA) in the CPPU-treated fruits

31 13 was recorded, the TSS/TA ratio and AsA content per fruit increased by the treatment. CPPU application at petal fall induced abnormally protruding fruit tip Cobalt Sulphate (CoSO 4 ) and its Effects Cobalt sulfate is an inorganic salt of divalent cobalt. It is the usual source of water-soluble cobalt, because it is more economical and has less tendency to dehydrate than cobalt chloride or cobalt nitrate (Budavari et al., 1996). Co 2+ is a potent inhibitor of ethylene biosynthesis. Williams and Golden (2002) studied purification and characterization of ACC oxidase from Artocarpus altilis and found that the enzyme ACC was inhibited by cobalt sulfate (CoSO 4 ). When applied in concentration of 0.1 mm, activity of enzyme ACC was only (0.09 ± 0.01) kat ml extract, and its percentage inhibition reached 97.1%, compared to control (1.11±0.03) kat ml extract. Singh and Agrez (2000) reported that single exogenous spray applications of CoSO 4 (200 mg/l) to fully-grown panicles of 'Kensington Pride' mango before anthesis, was most effective for improving fruit set, fruit retention and yield, compared to aminoethoxyvinylglycine (AVG), aminooxyacetic acid (AOA), and ethylene action inhibitor silver thiosulphate (STS).

32 III. MATERIALS AND METHODS 3.1. Time and Place The research was done at Postharvest Laboratory, Faculty of Agriculture, Laboratory of Food and Agricultural Product Process Engineering, Laboratory of Environmental and Agricultural Building, Faculty of Agricultural Technology, Bogor Agricultural University (IPB), starting from February 2010 to May Plant Material and Treatment The research was divided into two stages. The first experiment covered physical and chemical changes of mangosteen fruit treated with CPPU and CoSO 4 during storage, while the second one involved the study of physiological and its relation to color development of mangosteen fruit treated with CPPU and CoSO 4 during storage. The experimental design was arranged in a completely randomized block design with 2 factors and 3 replications. The first factor was cobalt sulphate (CoSO 4 ) at four concentrations (0, 500, 1000, and 2000 ppm), while the second one was CPPU at four concentrations (0, 10, 20, and 30 ppm). The combination of the above factors provided 16 treatments with 48 experimental units. Each experimental unit comprised 40 mangosteen fruit. For the second experiment, the design was as in the first experiment, but only cobalt sulphate at 0, 2000 ppm, and CPPU at 0, 30 ppm were used with 5 mangosteen fruit per experimental unit. The fruits used in the experiment were harvested from local orchard (Purwakarta) at stage 1(light greenish yellow with 5-50% scattered spots) on the same day and were of similar sizes. The harvested fruit were transported at night to Postharvest Laboratory. In the following morning, fruit were sorted, and washed with tap water to remove the dust. After washing, the fruit were air dried, and then treated with solution of fungicide TBZ 1 ppm for 30 seconds and air dried. Following fungicide application, air-dried fruit were dipped in the solution of CoSO 4 and CPPU for 30 seconds according to its concentrations used in the treatments. To facilitate the absorption of the solution by fruit, Tween 20 (1%) was added. After application, treated fruits were air dried, then immediately stored at o C (76-96% RH) which is an ideal storage temperature for mangosteen fruit.

33 Observed Variables Physical Attributes Fruit Resistance (kgf/cm 2 ) Mangosteen fruit was pressed until breakdown to see the level of easiness for fruit to be opened by using fruit resistance tool. The observation was done every two days with 16 times of observation, each of which two fruits were used Pericarp Water Content (%) Pericarp sample (g) were weighed, and placed in the paper envelope. The sample was dried in oven at 105 o C for 96 hours, then cooled down in desiccators and weighed. PWC was calculated using formula: Pericarp water content (%) = a b 100, where a = Fresh weight (g) Weight Loss a b = dried constant weight (g) Loss of fruit weight is measured based on the percentage of the reduction in the weight since the beginning up to the end of the storage period. The weight loss was calculated using the following formula: Weight loss (%) = W Wi W Fruit and Sepal Color 100, where W = Weight at initial storage (g) Wi = Weight at i th observation (g) The observation of fruit and sepal color was conducted every two days to see colour development during storage. Fruit and sepal color was measured using Color Reader CR-10 that was already calibrated. The tool consists of color notation (color system L, a, and b). Color system L means the brightness with value 0 (black) until 100 (white). The color system a and b is chromaticity coordinate. It means that chromatic mixture of red and green with value +a from 0 to +60 for red and a from 0 to -60 for green color. b value means that chromatic yellow and blue mixture with the value of +b from 0 to +60 for yellow color and the value b from 0 to -60 for blue color. The colour reading was measured twice at the equatorial region of each fruit and two sepals, and averaged to give a value for each fruit and sepal. The results were presented as lightness (L*, where

34 16 0=/black, 100= white color), a/b ratio and hue angle (h o ) with red-purple at an angle of 0 o, 90 o representing yellow color, and 180 o bluish-green color (Palapol et al., 2009). Hue angle was calculated using the following formula: Hue angle (h o ) = arctan (b/a) Chemical Attributes Total Soluble Solids (TSS) To measure total soluble solids on fresh juice, the white fresh of the arils with seeds, is wrapped in cheesecloth, and squeezed by hand to separate juice from seeds. Pulp liquid is placed on the prism of digital refractometer. TSS was reported as o Brix Titratable Acidity (Titration method AOAC 1984) Analysis of titratable acidity of the mangosteen fruit was measured in duplicate by using the titration method. Pulp was weighed as much as 10 g and put in a glass baker. Distilled water was added to get a solution of 100 ml, and then filtered with filter paper. Twenty five ml of the filtrate were titrated with 0.1 N NaOH using phenolphthalein (pp) as an indicator until the solution turns pink. Titratable acidity was calculated with following formula: TA(%) = ml NaOH N NaOH 64 df 100 mg sample Where, ml NaOH = NaOH Volume N = NaOH normality (0.1 N) df = dilution factor 64 = Equivalent weight of citric acid

35 Physiological Variables Respiration Rate Five fruits were weighed and placed in 3.3 L- glass jar and sealed with wax to prevent the entry of gas O 2 and CO 2 and stored in 15 o C. The carbon dioxide concentration measurement was done by using Shimadzu Infrared Gas Analyzer Model IRA-107, while O 2 was measured using Oxygen Portable Tester Model POT-101. The measurement was done every 3 hours on the first day (after treatment), every 6 hours on the second day, every 12 hours, and followed by every 24 hours. The rate of respiration was calculated with the following fomula: R = dx dt V W, where R = Respiration rate (ml kg-1 h -1 ) x = CO 2 concentation (%) t = Time (hour) V = Free volume (ml) W = Fruit weight (kg) Ethylene Production To measure ethylene production rate during period of storage, 5 treated fruits were packed in the 3.3 L-glass jar and kept in the temperature 15 o C. Gas Chromatograph (GC) with the FID system (Flame Ionization Detector) which was connected with a chroma-integrator D-2000 was used. The measurement was done by using the column (2000 mm x 4 mm) and the column activated mesh alumina. The column temperature for the measurement was 60 o C and injector temperature was 110 o C. N 2 carrier gas flow rate was 30 ml/minute and gas pressure 5 kg/cm 2. Mangsosteen fruit was incubated in the air-locked stopples, and sample was taken as much as 1 ml. Only 0.5 ml was injected into gas chromatograph. The measurement was done every 24 hours up to d13 of storage. Ethylene production rate was expressed as µl kg -1 h -1. Ethylene concentration was calculated based on the following formula:

36 18 Sample (ppm) = Sample peak area Standard peak area standard ( ppm) EP = de dt V W 3.4. Statistical Analysis Where, EP = Ethylene production rate (µl/kg/h) E = Ethylene concentration (ppm) t = time (hour) V = Space volume (L) W = Product weight (kg) All the recorded data was entered and stored in Microsoft Excel Analysis was performed using SPSS statistics Analysis of variance was done and treatment means were compared using Duncan Multiple Range Test (DMRT) at P<0.05.

37 IV. RESULTS AND DISCUSSION Experiment one: Physical and Chemical Changes of Mangosteen Fruit Treated with CPPU and CoSO 4 during Storage 4.1. Physical Changes of Mangosteen Fruit Fruit Resistance (kgf/cm 2 ) Fruit softening is closely associated with ripening process. The resistances of mangosteen fruit were similarly noticed during storage from d0 to day 30 at o C (76-96% RH) in both fruit treated with CPPU and CoSO 4 (Figure 2, 3). The results showed that mangosteen fruit could be stored at 15 o C for 30 days without affecting fruit hardness, and treatments applied had no effect on fruit hardening during storage period, except at day 16 and day 30 (Appendix table 1). At d16, CPPU 20 and 30 ppm had higher fruit resistance than CPPU 10 ppm and control fruit, while fruit treated with CPPU 20 ppm was most resistant and significantly different from CPPU 0, 10 and 30 ppm at day 30 (Appendix table 1). High resistant fruit treated with CPPU 20 ppm (2.70 kgf/cm 2, and 2.22 kgf/cm 2 at day 28 and d30, respectively) was due to fungal infection at the end of storage. Our results were consistent with Azhar (2007), who reported that mangosteen fruit pericarp was not difficult to be opened after 30 days of storage at 15 o C. The results also confirmed the findings by Inayati (2009), who found that BAP, a type of cytokinins, from 0 to 40 ppm could maintain the pericarp resistance at less than 2 kgf/cm 2 during 26 days of storage at 15 o C. Resistance values equally less than 2 are categorized as low, which indicate fruit are easily to be hand-opened.

38 20 Fruit resistance (kgf/cm²) 3,00 2,50 2,00 1,50 1,00 0,50 0,00 0 ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 2. Resistance of mangosteen fruit treated with CPPU during storage. 3,00 Fruit resistance (kgf/cm 2 ) 2,50 2,00 1,50 1,00 0,50 0 ppm 500 ppm 1000 ppm 2000 ppm 0, Storage time (days) Figure 3. Resistance of mangosteen fruit treated with CoSO 4 during storage Pericarp Water Content (%) Loss of water not only affects appearance or esthetic value but also reduces saleable weight, thus causing direct economic loss. Pericarp water content (%) was predicted to be concerned with mangosteen fruit hardening. PWC at d0 was almost the same in all treatments, and tended to decrease over storage time (Appendix table 2). PWC was 3-6% reduced at d30 in both fruit treated CPPU and

39 21 CoSO 4, and no statistical differences were observed, except day 18 which showed significant interaction between CPPU and CoSO 4. Pericarp water contents in fruit treated with CPPU 0 ppm + CoSO ppm, CPPU 10 ppm + CoSO ppm, CPPU 20 ppm + CoSO 4 0 ppm, CPPU 10, 20, 30 ppm + CoSO ppm were lowest and significantly different from control fruit at day 18 (Table 2). According to Kondo et al. (2003), skin hardening of mangosteen fruit during storage at low temperature was not accompanied by moisture loss. Table 2. Effects of CPPU and CoSO 4 interaction on pericarp water content (%) of mangosteen fruit during storage at day18 CPPU (ppm) CoSO₄ (ppm) ab d ab ab a ab bcd d cd abc bcd ab ab abc bcd ab Note: Different letters indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) Weight Loss (%) Mangoteen fruit increasingly lost weight with storage time from day 0 to day 30 in either fruit treated with CPPU or CoSO 4 (Figure 4, 5). The rate of weight loss in CPPU-treated fruit was lower than control fruit although no statistical significance was observed from day 2 to day 12 (Appendix table 3). Weight loss of fruit during storage was the results of water loss through transpiration (Yaman and Bayoindirli, 2002) and loss of carbon due to respiration (Pan and Bhowmilk, 1992). In mangosteen fruit, pericarp water content was only reduced 3-6% during storage time from d0 to d30 as seen in appendix table 2. This was not proportional to weight loss which ranged from 9-12%. The results suggested that water loss from aril and other parts of the fruit, and carbon loss by respiration contributed considerably in the loss of fruit weight.

40 22 Weight loss (%) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 4. Weight loss of mangosteen fruit treated with CPPU during storage ppm 500 ppm 1000 ppm 2000 pmm Weight loss (%) Storage time (days) Figure 5. Weight loss of mangosteen fruit treated with CoSO 4 during storage Fruit Color Lightness Fruit color is one of the most important appearance quality always employed by consumers when purchasing products. The darkening of mangosteen fruit drastically increased from day 0 to day 4, and was constant from day 4 to day 16. The darkening was reaccelerated from day 18 in either fruit treated with CPPU

41 23 and CoSO 4 (Figure 6, 7). Lightness of mangosteen fruit reduced (darkening increased) from 42 to 33 (around 9%) during storage time from day 0 to day 30. CPPU 20 ppm could most effectively delay darkening of the fruit and significantly varied from other concentrations as shown in day 4 and day 6 (Appendix table 4). Skin color (L) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 6. Changes in skin lightness of mangosteen fruit treated with CPPU during storage. Skin color (L) ppm 500 ppm 1000 ppm 2000 ppm Storage time (days ) Figure 7. Changes in skin lightness of mangosteen fruit treated with CoSO 4 during storage.

42 a/b Ratio a &b ratio in mangosteen fruit was increased from day 0 to day 4 and decreased considerably up to d30 in either fruit treated with CPPU and CoSO 4 (Figure 8, 9). The increased a/b was due to accumulation of red pigments in mangosteen during storage and was strongly associated with stage of fruit ripening. Research on colour development of mangosteen fruit conducted by Palapol et al. (2009) illustrated that a/b ratio of mangosteen fruit increased sharply from stage one to stage six when stored at 25 o C. The Increase was positively correlated with anthocyanin production in mangosteen fruit. As shown in the appendix table 7 neither CPPU nor CoSO 4 had significant effect on a/b ratio of mangosteen fruit over the storage time. 1,0 Skin color (a/b) 0,8 0,6 0,4 0,2 0 ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 8. Changes in skin color (a/b) of mangosteen fruit treated with CPPU during storage. 1,0 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0 ppm 500 ppm 1000 ppm 2000 ppm 0,1 0,0 Skin color (a/b) 0, Storage time (days) Figure 9. Changes in skin color (a/b) of mangosteen fruit treated with CoSO 4 during storage.

43 Hue angle (h o ) Hue value of fruit skin decreased from day 0 to day 4 and started increasing up to day 30. The trend of hue angle indicated that fruit underwent its color development to be redder or more purplish during early days of storage, and began to gradually turn yellow due to anthocyanin degradation over prolonged storage (Figure 10, 11). Application of CPPU and CoSO 4 did not show any effect on a/b ratio and hue angle of mangosteen fruit during storage period. Skin color (h ) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 10. Changes in skin color (h o ) of mangosteen fruit treated with CPPU during storage Skin color (h o ) ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 11. Changes in skin color (h o ) of mangosteen fruit treated with CoSO 4 during storage.

44 Sepal color Lightness Sepal color is the most important criterion and strongly affects consumers acceptance when purchasing mangosteen fruit. The lightness of mangosteen fruit sepal gradually decreased over storage time (Figure 12, 13). CPPU had no effect on sepal lightness among observed days, except day 14 (Appendix table 9). At day 14 CPPU 30 ppm could better maintain lightness (higher L value). Application of CoSO 4 at applied concentrations could reduce sepal lightness of mangosteen fruit during prolonged storage with statistical significance at day 2, day 14, day 24, and day 30. CoSO ppm tended to substantially accelerate sepal darkening during storage, especially at the end of storage (Appendix table 9) Sepal color (L) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 12. Changes in sepal color (L) of mangosteen fruit treated with CPPU during storage.

45 27 Sepal color (L) ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 13. Changes in sepal color (L) of mangosteen fruit treated with CoSO 4 during storage a/b Ratio and Hue angle a/b ratio of mangosteen fruit sepal at the initial storage was negative, implying that the sepal was very fresh and green. However, sepal turned brown over prolonged storage with an increase in a/b ratio Figure 14 and Figure 15, and decreased hue value as shown in Figure 16, and Figure 17. The brown color was due to the degradation of chlorophyll, synthesis of other pigments and loss of water. 0,35 0,30 0 ppm 10 ppm 20 ppm 30 ppm Sepal color (a/b) 0,25 0,20 0,15 0,10 0,05 0,00-0, Storage time (days) Figure 14. Changes in sepal color (a/b) of mangosteen fruit treated with CPPU during storage.

46 28 Sepal color (a/b) 0,35 0,30 0,25 0,20 0,15 0,10 0,05 0,00-0,05 0 ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 15. Changes in sepal color (a/b) of mangosteen fruit treated with CoSO 4 during storage. Sepal color (h o ) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 16. Changes in sepal color (h o ) of mangosteen fruit treated with CPPU during storage.

47 29 Sepal color (h o ) ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 17. Changes in sepal color (h o ) of mangosteen fruit treated with CoSO 4 during storage. Table 3 showed that there were significant interactions between CPPU and CoSO 4 on a/b ratio of mangosteen fruit sepal at day 22 and day 26. The a/b was significantly higher in fruit treated with CPPU 0 pmm + CoSO ppm (0.37) than control (0.27) at day 22. At day 26, CPPU 30 ppm and CoSO ppm gave higher a/b (0.41) and statistically significant compared to control fruit with a/b only The result showed that application of Cobalt Sulphate was likely to accelerate redness of the sepal (increase a value) as seen in appendix table 10. Table 3. Effects of CPPU and CoSO 4 interaction on a/b ratio of sepal of mangosteen fruit during storage at d22 and d26 Day CoSO CPPU (ppm) 4 (ppm) c 0.30 bc 0.27 c 0.37 a ab 0.30 bc 0.30 bc 0.30 bc ab 0.29 bc 0.31 bc 0.34 ab bc 0.30 bc 0.33 ab 0.33 ab bc 0.31 bcd 0.27 d 0.35 ab ab 0.31 bcd 0.31 bcd 0.33 bc bc 0.30 bcd 0.35 bc 0.36 ab bcd 0.29 cd 0.32 bcd 0.41 a Note: Different letters indicate significant differences among treatment means (P < 0.05) by Duncan s ultiple range test (DMRT)

48 30 As shown in Table 4 control fruit had higher hue angle and significantly different from fruit treated with CPPU 0 ppm + CoSO ppm, CPPU 20 ppm + CoSO ppm, and CPPU 30 ppm + CoSO ppm at day 22. Hue angle of fruit treated with CPPU 0 ppm + CoSO ppm was significantly higher from the combination of CPPU 30 ppm + CoSO ppm, and control fruit at day 26. Table 4. Effects of CPPU and CoSO 4 interaction on hue angle of sepal of mangosteen fruit during storage at day 22 and 26 Day CPPU (ppm) CoSO 4 (ppm) a abc ab d bcd abc abc abc bc abc abc cd abc abc cd cd bc abc a cd cd abc abc cd cd abc bc cd abc ab abc d Note: Different letters indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) Visual Observation Visual appearance of the fruit is very important factor which strongly affect consumers acceptance whether to buy the product or not. In general, mangosteen fruit sepal turns brown soon after a few days of storage in ambient air, but the sepal freshness can be maintained longer when stored in cold storage at 15 o C, and proper postharvest treatment. In this experiment, mangosteen fruit sepal was very green and fresh during initial days of storage. However, some parts of sepal turned brown as from storage day14 and the brown part had gradually spreaded on to the whole part of the sepal from day 18. Visual effects of the treatment on the fruit was almost the same with control fruit, but CPPU 30 ppm was likely to maintain better greenness of the sepal (Appendix 19). This was an indicator that manogsteen fruit were less marketable as from day 18. The color of mangosteen fruit was reddish pink (stage 3) at the start of storage, and changed to reddish purple (stage 4) after 2 days of storage. The color of mangosteen fruit was not developed into black purple as stored in room

49 31 temperature. Instead, brown spots on fruit skin were observed at storage day 8 and the spots were gradually enlarged up to the end of storage (Appendix 19) Chemical Changes of Mangosteen Fruit Total Soluble Solids (TSS) Total soluble solids of the fruit are considered one of the basic criteria for quality evaluation. Total soluble solids of mangosteen fruit during storage decreased linearly over storage time (Figure 18, 19). CoSO 4 did not affect TSS at all observed days (Appendix table 14). At day 12 response of CPPU 30 ppm was the same with control, but significantly different from CPPU 10 ppm and CPPU 20 ppm. CPPU 30, 10 and 0 ppm gave the same response, and statistical different from CPPU 20 ppm at day 16. The reduction of total soluble solids was around 4-5% in all treatments at the end of storage (Appendix table 14). According to Palapol et al. (2009), TSS of mangosteen harvested at stage 1 was around 15% and linearly increased to 17% at stage 5 and 6 during storage at 25 o C. The findings revealed that mangosteen fruit underwent fast physiological changes under room temperature. However, those changes become very slow when fruit were stored at 15 o C as indicated in our results. Generally, TSS increases during ripening process and tends to decrease during prolonged storage which was caused by the breakdown of simple sugar content into alcohol, aldehide, and amino acids (Winarno and Aman, 1981). As reported in litchi fruit, concentrations of ascorbic acid, phenols, sugars and organic acids decrease during storage (Holcroft and Mitcham, 1996; Chen et al., 2001).

50 32 Total soluble solids ( Brix) ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 18. Changes in total soluble solids of mangosteen fruit treated with CPPU during storage. Total soluble solids( o Brix) ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 19. Changes in total soluble solids of mangosteen fruit treated with CoSO 4 during storage Titratable Acidity (TA) Titratable acidity in mangosteen fruit tended to be fluctuated during storage time (Figure 20, 21). CPPU showed significant effect on the reduction of titratable acidity at day 14, day 16, and day 30 with CPPU 20 ppm, and 30 ppm being the most effective. The effect of CoSO 4 was observed at day 8, while other observed days showed no significance at all applied concentrations (Appendix table 15). The results revealed that titratable acidity of mangosteen fruit was only

51 33 slightly reduced during 30 days of storage. The finding was similar with Palapol et al. (2009), who reported that TA in mangosteen was 0.77 gram per 100 ml at stage 1 and slightly decreased at stage 6 during storage at 25 o C. In mango fruit, titratable acidity decreased with increased storage time (Abbasy et al., 2009). Increased activity of citric acid during ripening or reduction in acidity may be due to their conversion into sugars and their further utilization in the metabolic processes of the fruit. The decreased acidity during storage demonstrated fruit senescence as reported by El-Ghaouth et al. (1991) and Garcia et al. (1998). Titratable acidity (%) 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 0 ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 20. Changes in titratable acidity of mangosteen fruit treated with CPPU during storage. Titratable acidity (%) 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0,0 0 ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 21. Changes in titratable acidity of mangosteen fruit treated with CoSO 4 during storage.

52 TSS/TA Ratio The relative sweetness or sourness of mangosteen fruit is determined by its ratio of sugars to acids. TSS/TA ratio gradually decreased according to storage time (Figure 22, 23). CPPU application was significant effective at day 14, day 16 and day 30 with concentration of 20 ppm being the most effective one. In contrast, CoSO 4 did not show any response (Appendix table 16), but significant interaction between CPPU and CoSO 4 was observed at day 18 (Table 5). The decreased TSS/TA was mainly due to the decreased total soluble solids rather than titratable acidity during storage time. The TSS &TA was noticeably higher in CPPU-treated fruit. Our results confirmed the findings by Kim et al. (2006), who reported that the TSS/TA ratio of hard kiwifruit per fruit increased with CPPU application TSS/TA ppm 10 ppm 20 ppm 30 ppm Storage time (days) Figure 22. Changes in TSS/TA of mangosteen fruit treated with CPPU during storage.

53 TSS/TA ppm 500 ppm 1000 ppm 2000 ppm Storage time (days) Figure 23. Changes in TSS/TA of mangosteen fruit treated with CoSO 4 during storage. Table 5. Effects of CPPU and CoSO 4 interaction on TSS/TA ratio of mangosteen fruit during storage at d18 CoSO₄ (ppm) CPPU (ppm) ab a bc c c bc c abc bc bc abc bc c abc abc bc Note: Different letters indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT). Experiment two: Physiological Changes and Colour Development of Mangosteen Fruit Treated with CPPU and CoSO 4 during Storage 4.3. Physiological Changes and its Relation to Color Development Respiration Rate of Mangosteen Fruit Respiration rate of mangosteen was very fluctuant during storage at hour 3 to hour 60 (Figure 24). The fluctuation was because of the adaptation of mangosteen fruit to microclimate during early storage. After adaptation, the respiration remained constant from h72. The respiration was highest at hour 3

54 36 when measured at the first three hours of storage after treatment. The peak may not represent climacteric peak, but indicated early adaptation of fruit from room temperature, where treatments were applied, to cold storage at15 o C. CPPU and CoSO 4 showed similar effect which could reduce respiration by 37%, while the combination of two substances could reduce only 28% compared to control (Appendix table 17). As shown in Table 6, there were significant interactions between CPPU and CoSO 4 at hour 300, 372, 492, 516, 540, 564, and 588. CPPU 30 ppm had the same effect to inhibit respiration as CoSO ppm and significantly different from control and the combination of the two substances at hour 300, 372 and 492. However, CPPU and/or CoSO 4 were similarly effective and statistically significant from control at hour 516, 540, 564, and 588 (Table 6). Mangosteen fruit is a climacteric fruit which shows the characteristic changes after harvesting. Kader (2003) recommended that the fruit produced CO 2 at the rate of 6-10 ml/kg/h at 20 o C could maintain postharvest quality. The amount of CO 2 recommended was similar to that found in our experiment. Although mangosteen fruit is generally grouped as climacteric fruit, many researches including our research did not find a clear climacteric pattern when fruit were stored at 15 o C. Respiration rate (CO 2 ml kg 1 h 1 ) ppm 0 ppm 30 ppm 0 ppm 0 ppm 2000 ppm 30 ppm 2000 ppm Storage time (hours) Figure 24. Respiration rate of mangosteen fruit treated with CPPU and CoSO 4 during storage. Hour 0 was the measurement before treatment.

55 37 Table 6. Effects of CPPU and CoSO 4 interaction on respiration rate of mangosteen fruit during storage CPPU*CoSO 4 Storage time (hours) ,0 9.11a 9.45 a a a a a a 0, b 8.00 b 6.85 b 7.34 b 6.83 b 8.46 b 8.23 b 30, b 7.97 b 6.60 b 8.23 b 7.52 b 8.78 b 8.42 b 30, a 9.31 a 9.49 a 8.62 b 7.30 b 8.18 b 7.34 b Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT). Day 0 means the measurement before treatment application Ethylene Production of Mangosteen Fruit Ethylene production of mangosteen fruit was produced at a very low rate from the early storage to day 5, then increased and reached its peak at day 7 during storage at 15 o C (Figure 25). After the peak, ethylene production decreased very sharply. Rate of ethylene production by the fruit did not vary significantly among the treatments. However, CPPU, CoSO 4, and the combination could reduce ethylene production as much as 65%, 55%, and 33%, respectively at the peak day. Low production rate of ethylene in CoSO 4 treated fruit were the results of the suppression of ACC enzyme activities by Co 2+ as reported by Williams and Golden (2002). Fruit treated with CPPU also showed similar effect as CoSO 4. According to Serek and Reid (1997), cytokinins were also effective to reduce the sensitivity of plants to ethylene. A previous publication by Palapol et al. (2009) indicated that mangosteen fruit harvested at stage 1 had the highest ethylene production when the fruit reached stage 5 at d5 of storage at 25 o C.

56 38 Ethylene production (µl kg 1 h 1) ppm 0 ppm 30 ppm 0 ppm 0 ppm 2000 ppm 30 ppm 2000 ppm Storage time (days) Figure 25. Ethylene production of mangosteen fruit treated with CPPU and CoSO 4 during storage. Day 0 represents measurement before treatment Lightness and Hue angle of Mangosteen Fruit L value of mangosteen fruit decreased gradually during storage up to day 10, then remained constant up to day 28 (Figure 26). CPPU and CoSO 4 did not show any significant differences over 28 days of storage. Hue angle of mangosteen fruit ranged from 60 to 70 at the early storage. However, it decreased gradually during storage up to day 10, and then increased again up to the end of storage (Figure 27). The decreased hue value at the early days of storage indicated that mangosteen fruit were under ripening process. During ripening, mangosteen fruit accumulated anthocyanins in the pericarp, which resulted in redness or purple color of mangosteen fruit. The pigment started to be degraded over prolonged storage, which led to increased hue angle. An increased hue value was due to low anthocyanins. Low anthocyanin may be the result of low ethylene production during storage or anthocyanin degradation to other compounds. According to Palapol et al. (2009) ethylene production of mangosteen fruit increased linearly with anthocyanin, while hue angle decreased sharply from stage 1 to stage 6 when stored at 25 o C.

57 39 Skin color (L) ppm 0 ppm 30 ppm 0 ppm 0 ppm 2000 ppm 30 ppm 2000 ppm Storage time (days) Figure 26. Changes in lightness of mangosteen fruit treated with CPPU and CoSO 4 during storage. Skin color (h ) ppm 0 ppm 30 ppm 0 ppm 0 ppm 2000 ppm 30 ppm 2000 ppm Storage time (days) Figure 27. Changes in Hue angle (h o ) of mangosteen fruit treated with CPPU and CoSO 4 during storage.

58 V. CONCLUSION AND SUGGESTION CONCLUSION Postharvest treatments of either CPPU or CoSO 4 were found to have low effectiveness on the component of postharvest quality of mangosteen fruit although sporadic significances were observed among observed times. The resistance of mangosteen fruit was lower than 2 kgf/cm 2, representing fruits were still easily be opened up to 30 days of storage. However, visual appearance of the fruit was less attractive as from day 18, especially sepal. Application of either CPPU or CoSO 4 was ineffective in inhibiting mangosteen fruit hardening. Application of either CPPU or CoSO 4 was found to be effective in reducing respiration rate as from hour 516, but not in ethylene production in mangosteen fruit during storage at 14 o C-16 o C (76-96% RH). Mangosteen fruit is a climacteric fruit with high ethylene production after harvest. However, no clear peak of respiration was observed during cold storage. Fruit colour changes were closely associated with ethylene production. SUGGESTION Further research on postharvest application using CPPU on mangosteen fruit is suggested, especially soon after fruits are harvested.

59 41 REFERENCES Abbasi NA, Zafar I, Maqbool M, Hafiz IA Post harvest quality of mango (Mangifera indica L.) fruit as affected by chitosan coating. Pakistan Journal of Botany 41: Arora, A Programmed cell death during plant senescence. In: Paliyath J, Morr DP, Handa Ak, Lurie S, editors. Postharvest Biology and Technology of Fruits, Vegetables, and Flowers. Wiley-Blackwell Publishing. pp Anggraeni W Penggunaan bahan pelapis dan plastik kemasan untuk meningkatkan daya simpan buah manggis (Garcinia mangostana L.) [skripsi]. Bogor: Fakultas Pertanian, Institut Pertanian Bogor. Augustin MA, Azudin MN Storage of mangosteen (Garcinia mangostana L.). ASEAN Food J 2: Azhar KS Pengkajian bahan pelapis, kemasan dan suhu penyimpanan untuk memperpanjang masa simpan buah manggis [thesis]. Bogor: Sekolah Pascasarjana, Institut Pertanian Bogor. Baker L The potential for mangosteen in eastern Indonesia. SADI-ACIAR research report. Barry CS, Giovannoni JJ Ethylene and fruit ripening. J Plant Growth Regul 26: Bleecker AB, Kende H Ethylene: a gaseous signal molecule in plants. Annu. Rev. Cell Dev. Biol. 16: Bouzayen M, Latche A, Nath P, Pech JC Mechanism of Fruit Ripening. In: Pua EJ, Davey MR, editors. Plant Development Biology- Biotechnological Perspective. Heidelberg Dordrecht London New York: Springer, pp Bower J, Holford P, Latche A, Pech JC Culture conditions and detachment of the fruit influence the effect of ethylene on the climacteric respiration of melon. Postharvest Biol Technol 26: Bunsiri A Characterization of lignin and enzymes involved in the increased firmness of mangosteen fruit pericarp after impact. Ph.D Dissertation. Kasetsart University, Bangkork. Chaves ALS, de Mello-Farias PC Ethylene and fruit ripening: from illumination gas to the control of gene expression, more than a century of discoveries. Genet Mol Biol 29:

60 42 Chen W, Wu Z, Ji Z, Su M Post-harvest research and handling of litchi in China - a review. Acta Hort. 558: Cruz-Castillo JG, Woolley DJ, Lawes GS Kiwifruit size and CPPU response are influenced by the time of anthesis. Sci. Hort. 95: Cruz-Castillo JG, Woolley DJ, Lawes GS Effect of CPPU and other plant growth regulators on fruit development in kiwifruit. Acta Hort. 498: Dangcham S, Bowen J, Ferguson IB, Ketsa S Effect of temperature and low oxygen on pericarp hardening of mangosteen fruit stored at low temperature. Postharv. Biol. Technol. 50: Davies PJ Plant Hormones: Biosynthesis, Signal Transduction, Action. 3 rd ed. The Netherlands: Kluwer Academic Publishers. pp 7-9. Direktorat Jenderal Hortikultura Data dan Satistick. [September 28, 2009]. Ekaputri DP Pengaruh pemberian kitosan dan GA3 terhadap shelf-life buah manggis (Garcinia mangostana L.) [Skripsi]. Bogor: Fakultas Pertanian, Institut Pertanian Bogor. El Ghaouth A, Arul J, Ponnampalam R, Boulet Chitosan coating effect on storability and quality of fresh strawberries. J Food Sci 56: Ferrante A, Fancini A Ethylene and Leaf Senescence. In: Khan NA, Editor. Ethylene Action in Plants. New York: Springer-Verlag Berlin Heidelberg. pp Gan S The Hormone Regulation of Senescence. In: Davies PJ, editor. Plant Hormones: 3 rd ed. Kluwer Academic Publishers, the Netherlands: Garcia MA, Martino MN, Zaritszky NE Plasticized starch-based coatings to improve strawberry (Fragaria anannasa) quality and stability. J.Agric. Food Chem. 46: Giovannoni JJ Molecular biology of fruit maturation and ripening. Annu Rev Plant Physiol Plant Mol Biol 52: Giovannoni JJ Genetic regulation of fruit development and ripening. Plant Cell Suppl 16: S170 S180. Grey J, Pigson S, Shabbeer J, Schuch W, and Grierson D Molecular biology of fruit ripening and its manipulation with antisense genes. Plant.Mol.Biol.19:69-87.

61 43 Holcroft DM, Mitcham EJ Postharvest physiology and handling of litchi (Litchi chinensis Sonn). Postharvest. Biol. Technol. 9: Huber D, Jeong, Riternou M Use of 1-Methylcyclopropene (1-MCP) on Tomato and Avocado Fruits: potential for enhanced shelf life and quality retention. Institute of Food and Agricultural Sciences, University of Florida. Inayati UK Pengaruh pemberian bahan pelapis dan sitokinin dalam memperpanjang umur simpan buah manggis (Garcinia mangostana L.) [skripsi]. Bogor: Fakultas Pertanian, Insititut Pertanian Bogor. Jo YS, Cho MY, Park JO, Park TD, and Shim KK Comparison of CPPU effect on fruit development in several Actinidia species. Acta Hort. 610: Juanasri Pengaruh umur petik, pemberian giberelin, dan spermidin terhadap kualitas buah manggis (Garcinia mangostana L.) [thesis]. Bogor: Sekolah Pascasarjana, Institut Pertanian Bogor. Kader AA Mangosteen recommendation for maintaining postharvest quality. http./rics.ucdavis.edu/postharvest2//produce/producefacts/fruitmangosteen.s html.[23 November 2003]. Kanchanapom K, Kanchanapom M Mangosteen. In: Shaw PE, Chan JrHT, Nagi S, editors. Tropical and Subtropical Fruits. AgScience Inc., USA: Kende H Ethylene biosynthesis. Annu Rev Plant Physiol Plant Mol Biol 44: Ketsa S, Atantee S Phenolics, lignin, peroxidase activity and increased firmness of damaged pericarp of mangosteen fruit after impact. Postharv. Biol. Technol. 14: Kim JG et al CPPU application on size and quality of hardy kiwifruit. Acta Hort. 110: Klee HJ, Lanahan MB Transgenic Plants in Hormone Biology. In: Davies PJ, editor. Plant Hormones: Physiology Biochemistry and Molecular Biology. The Netherlands: Kluwer Academic Publishers. pp Kondo S, Ponrod W, Kanlayanarat S, Hirau N Relationship between ABA and chilling injury in mangosteen fruit treated with spermine. Plant Growth Regulation, 39: Lelie`vre JM, Latche A, Jones B, Bouzayen M, and Pech JC Ethylene and fruit ripening. Plant Physiol. 101:

62 44 McKeon TA, Fernandez-Maculet JC, Yang SF Biosynthesis and metabolism of ethylene. Davies PJ, editor. Plant Hormones: Physiology, Biochemistry and Molecular Biology. The Netherlands: Dordrecht: Kluwer. pp MOA Business Proposal for the Commercial Cultivation of Mangosteen (Garcinia mangostana L.). Ministry of Agriculture, Malaysia. Osman B, Milan MR Mangosteen Garcinia mangostana L. William JT, Smith RV, Haq N, Dunsiger Z, editors. Southampton Centre for Underutilised Crops, University of Southampton, Southampton, UK, pp Palapol Y et al Color development and quality of mangosteen (Garcinia mangostana L.) fruit during ripening and after harvest. Postharv. Biol. Technol. 51: Paliyath G, Tiwari K, Yuan H, Whitaker BD Structural Deterioration in Produce: Phospholipase D, Membrane Deterioration, and Senescence. In: Paliyath J, Morr DP, Handa Ak, Lurie S, editors. Postharvest Biology and Technology of Fruits, Vegetables, and Flowers. Wiley-Blackwell Publishing. pp Pratiwi HH Pengaruh pelapisan dan sitokinin terhadap kesegaran cupat dan umur simpan buah manggis (Garcinia mangostana L.) [skripsi]. Bogor: Fakultas Pertanian, Institut Pertanian Bogor. Pan JC, Bhowmilk SR Shelf life of mature green tomatoes stored in controlled atmosphere and high humidity. J.Food Sci, 57: Pathak N, Asif MH, Dhawan P, Srivastava MK, and Nath P Expression and activities of ethylene biosynthesis enzymes during ripening in banana fruits and effect of 1 MCP treatment. Plant Growth Regul 40: Qanitah Kajian perubahan mutu buah manggis (Garcinia mangostana L.) dengan perlakuan precooling dan penggunaan giberelin selama penyimpanan [thesis]. Bogor: Sekolah Pascasarjana, Institut Pertanian Bogor. Radha T, Mathew L Fruit Crops. Horticultural Science Series-3. New India Publishing Agency, New Delhi, India. pp Salisbury FB, Ross CW Plant Physiology. Belmont, CA: Wadsworth, pp , Salveit ME Jr Internal carbon dioxide and ethylene levels in ripening tomato fruit attached to or detached from the plant. Physiol Plant 89:

63 45 Shellie KC, Salveit ME Jr The lack of a respiratory rise in muskmelon fruit ripening on the plant challenges the definition of climacteric behaviour. J Exp Bot 44: Serek M, Reid MS Use of Growth regulators for imporving the postharvest quality of ornamentals. Perishables Handling Quarterly Issue No. 92. Seymour GB, Fray RG, Hill P, Tucker GA Down-regulation of two-non homologous endogenous tomato gene with a single chimaeric sense gene construct. Journal of Plant Molecular Biology. 23:1-9. Sisler EC, Serek M Inhibitors of ethylene responses in plants at the receptor level: recent developments. Physiol Plant 100: Sisler EC, Dupille E, Serek M Effects of 1-methylcyclopropene and methylcyclopropene on ethylene binding and ethylene action on cut carnation. Plant Growth Regul 18: Silva E Respiration and ethylene and their relationship to postharvest handling: a farmer's guide to selling, postharvest handling, and packing produce (Midwest edition). [September 28, 2009]. Singh Z, Agrez V Fruit set, retention and yield of mango in relation to ethylene. Abstract. Acta Hort Suryanti S, Roosmani ABST, Sjaifullah Penyimpanan buah manggis segara dalam atmosphere termodifikasi pada berbagai suhu dingin. J.Hort.8: Tongdee SC Mangosteen. Second Progress Report ACIAR Project No TISTR, Bangkok, Thailand. Uthairatanakij A, Ketsa S Physico-chemical changes of pericarp of mangosteen fruits after low temperature storage. In: Vijaysegaran S, Pauziah M, Mohamed MS, and Ahmad Tarmizi S, editors. Proc. Intl. Conf. Trop. Fruits. Vol. 1, Malaysian Agric. Res. Dev. Inst. (MARDI), Serdang, Salangor, pp Watkins CB The use of 1-methylcyclopropene (1-MCP) on fruits and vegetables. Biotechnol. Adv. 24: Wiebel J, Chacko EK, Downton WJS Mangosteen (Garcinia mangostana L): a potential crops for tropical northern Australia. Acta Hort. 321: Williams OJ, Golden KD Purification and characterization of ACC oxidase from Artocarpus altilis. Plant Physiol.Biochem.40: Winarno FG, Aman Fisiologi Lepas Panen, PT. Gramedia, Jakarta.

64 46 Yaman O, Bayoindirli L Effects of an edible eating and cold storage on shelf-life and quality of cherries. Lebensm-Wis.Und-Technol 23: Yang SF, Hoffman NE Ethylene biosynthesis and its regulation in higher plants. Annu. Rev. Plant Physiol 35:

65 Appendix table 1. Effects of CPPU and CoSO 4 on resistance (kgf/cm 2 ) of mangosteen fruit during storage Treatment CPPU Storage time (days) b b b b a a a b CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT)

66 Appendix table 2. Effects of CPPU and CoSO 4 on pericarp water content (%) of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interaction ns ns ns ns ns ns ns ns * ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT)

67 Appendix table 3. Effects of CPPU and CoSO 4 on weight loss (%) of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT)

68 Appendix table 4. Effects of CPPU and CoSO 4 on lightness (L) value of mangosteen fruit during storage Treatment CPPU Storage time (days) b b b b a a ab b CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 50 50

69 Appendix table 5. Effects of CPPU and CoSO 4 on a value (red-green) of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ a b a b b a ab b Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 51 51

70 Appendix table 6. Effects of CPPU and CoSO 4 on b value (yellow-blue) of mangosteen fruit during storage Treatment CPPU Storage time (days) b 8.95 a 9.44 b 8.76 b b bc b 9.06 a 9.62 b 8.79 b b c a b ab 9.84 a a a a 9.66 ab a 9.13 b b ab CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 52 52

71 Appendix table 7. Effects of CPPU and CoSO 4 on a/b value of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 53 53

72 Appendix table 8. Effects of CPPU and CoSO 4 on hue angle of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 54 54

73 Appendix table 9. Effects of CPPU and CoSO 4 on lightness (L value) of sepal of mangosteen fruit during storage Treatment CPPU Storage time (days) bc c ab a CoSO₄ a a a a b a a a b ab ab a b b b b Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 55 55

74 Appendix table 10. Effects of CPPU and CoSO 4 on a value (red-green) of sepal of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ a b b a Interaction ns ns ns ns Ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 56 56

75 Appendix table 11. Effects of CPPU and CoSO 4 on b value (yellow-blue) of sepal of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ a a ab a ab ab b b Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 57 57

76 Appendix table 12. Effects of CPPU and CoSO 4 on a/b ratio of sepal of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns * ns * ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 58 58

77 Appendix table 13. Effects of CPPU and CoSO 4 on hue angle of sepal of mangosteen fruit during storage Treatment CPPU Storage time (days) CoSO₄ Interactoin ns ns ns ns ns ns ns ns ns ns ns * ns * ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 59 59

78 Appendix table 14. Effects of CPPU and CoSO 4 on total soluble solids ( o Brix) of mangosteen fruit during storage Treatment CPPU Storage time (days) a ab b b b a a b CoSO₄ Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 60 60

79 Appendix table 15. Effects of CPPU and CoSO 4 on titratable acidity (%) of mangosteen fruit during storage Treatment CPPU Storage time (days) ab 0.72 a b a a 0.75 a ab b b 0.62 b a b b 0.68 ab a b CoSO₄ ab ab a b Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 61 61

80 Appendix table 16. Effects of CPPU and CoSO 4 on TSS &TA ratio of mangosteen fruit during storage Treatment CPPU Storage time (days) a ab b a b a b b b a b a a b a b a b b a CoSO₄ Interaction ns ns ns ns ns ns ns ns ns * ns ns ns ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05) by Duncan s multiple range test (DMRT) 62 62

81 Appendix table 17. Changes in respiration rate of mangosteen fruitt treated with CPPU and CoSO 4 during storage Treatment Respiration rate (ml kg -1 h -1 ) at i th hour CPPU (ppm) a b CoSO 4 (ppm) b b a a Interaction ns ns ns ns ns ns ns ns ns ns ns ns ns ns ns Treatment CPPU (ppm) CoSO 4 (ppm) Interaction ns ns ns ns ns ns ns ns * * ns * ns ns ns 63 63

82 Treatment CPPU (ppm) a a a a a b 8.48 b 7.88 b 8.12 b 8.29 b 9.17 CoSO 4 (ppm) a a a a a b 7.06 b 8.32 b 7.79 b 8.19 b Interaction ns * * * * * ns ns ns Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05). Day 0 means the measurement before treatment application

83 Appendix table 18. Ethylene production of mangosteen fruit treated with CPPU and CoSO 4 during storage Treatment CPPU (ppm) Ethylene production (µl kg -1 h -1 ) at i th day ` CoSO 4 (ppm) CPPU*CoSO 4 0, , , Note: Different letters in the same column indicate significant differences among treatment means (P < 0.05). Day 0 means the measurement before treatment application

84 66 Appendix 19. Images of mangosteen fruit treated with CPPU and CoSO 4 during storage Image before treatment (day 0) Images at day 2

85 67 Images at day 4 Images at day 6

86 68 Image at day 8 Images at day 10

87 69 Images at day 12 Images at day 14

88 70 Images at day 16 Images at day 18

89 71 Images at day 20 Images at day 22

90 72 Images at day 24 Images at day 26

91 73 Images at day 28 Images at day 30