South Indian Journal Of Biological Sciences 2016; 2(1); 207 212 ONLINE ISSN: 2454 4787 Research Article Preliminary phytochemical and nutritional profiles of an underutilized vegetable Sechium edule (Jacq.) Swartz. Greeshma Premkumar 1, * 1 Carmel College, Mala, Affiliated to University of Calicut, Kerala, India * Corresponding author: Greeshma Premkumar; E mail: greeshu10@gmail.com; Tel.: +919497623911 Received 1 August 2015; Revised 21 September 2015; Accepted 29 September 2015; Published 2 January 2016 Abstract The current investigation deals with the extraction and preliminary phytochemical and nutritional characterization of one of the underutilized crop, Sechium edule (Jacq.) Swartz. The phytochemical analysis revealed the presence of wide array of phytochemical including flavinoids, phenol, coumarin, tannin, terpinoids, saponin, steroids. The nutrient analysis was achieved by fresh Sechium edule (Jacq.) Swartz. by analysis of total sugar, phenol, protein, vitamin c, and carbohydrate, minerals such as iron, manganese, zinc, and calcium. The methanolic extract had significant quantity of minerals. However calcium was present in high quantity than iron, manganese and zinc. Sugar and carbohydrate contain very lower amount. Indicating that the fruit Sechium edule (Jacq.) Swartz are phytochemical rich and lower carbohydrate content used to prevent chronic disease cardiovascular disease, metabolic syndrome, high blood pressure and diabetes. Keywords: Sechium edule. Phytochemicals, Minerals, Extracts, Analysis 1. Introduction Plants dominate in the earth by their abundance. The green plant is fundamental to all other life. The oxygen we breathe, the nutrients we consume, the fuels we burn and many of the most important material we use where produced by plants. Fruits and vegetables have historically been considered rich sources of some essential dietary micronutrients and fibers and more recently have been recognized as important sources for and more recently have been recognized as important sources for a wide array of phytochemical that individually, or in combination may benefit health. About 600 species constitute the global diversity in vegetable crops. However, presently only one fourth is utilized as a major vegetable crops and rest are named as minor, underutilized, rare vegetables, wild edible vegetables or so on (Aberoumand and Deokule 2009). The distinction between underutilized and life support species is by no means strict. The life support species help to sustain life in stress prone habitats under abiotic stresses like temperature, soil and water and in emergency situations (Paroda et al., 1988) 207
Most of the vegetables and fruits were mainly consumed for their nutritional values without much considering their medicinal importance and very few species have been explored for chemicals and biological studies. Cucurbitaceae family includes 130 genera and 800 species have a large range of fruit characteristics which are eaten when mature or immature Sechium edule, is a delicious and versatile vegetable member of the cucurbit family which is fast becoming one of the top specialty vegetables in the United States (Cushnie and Lamb 2005). It is also known as sayote, choko, chocho, chow chow and vegetable pear, mirliton pear, this prolific climbing plant originated in Mexico and Guatemala and is now an important food in tropical and subtropical regions of the world. The chayote is an herbaceous perennial climbing vine which may up to 50 feet or more in length. The plants with yellow, greenish white flowers, are monoecious The pear shaped fruits about the size of a mango have a smooth or spiny, white to pale green skin with a firm, delicate nut flavored flesh. 2. Materials and methods 2.1. Collection of vegetables Fresh Sechium edule (Jacq.) Swartz. were procured from Elite supermarket, Thrissur, in the month of November 2015 for experimental purposes. The vegetables are extracted by cold extraction method using methanol. 2.2. Molisch s test For this test 2 ml of aqueous extracts was taken in a test tube. To the extract added 2 drops of molisch s reagent. Gently poured concentrated H2SO4 along the side of the test tube. Reddish brown ring was formed at the junction between H2SO4 and the aqueous extract indicating the presence of carbohydrate. 2.3. Benedict s test Five mili liter of benedict s reagent was mixed with the extract. Boiled for 2 minutes and cooled for some time. Appearance of an orange precipitate indicated a positive test for carbohydrates. 2.4. Fehling s test Filtrate was treated with 2 ml of each Fehling s solution A and B and mixed and boiled. Formation of red precipitate which indicates the presence of carbohydrate. 3.5. Biuret test Three mili liter of biuret reagent was added to a test tube containing equal volume of aqueous extract. Appearances of violet colour indicated the presence of protein. 3.6. Nitric acid test Three mili liter of concentrated nitric acid was taken in a test tube. The extract was added slowly along the side of the test tube. Protein gives a dark ring at the zone of contact between nitric acid and the extract. 3.7. Dragendroff s test Few drops of Dragendroff s reagent were added to the extract. Observed for the formation of orange yellow precipitate indicated for the presence of alkaloids. 208
3.8. Mayer s test Few drops of Mayer s reagent were added to the extract. Observed the formation of white or cream colour precipitate as an indication for the presence of alkaloids. 3.9. Wagner s test Few drops of Wagner s reagent were added to the extract. Observed the formation of reddish brown precipitate which indicated the presence of alkaloids. 3.10. Marquis test To the sample solution 3 ml of concentrated H2SO4 and 2 drops of 40% formaldehyde. A dark orange or purple precipitate was indication of alkaloids. 3.11 Analysis of total sugar Ten gram sample was taken and added 1mL concentrated HCl and 50 ml water refluxed in water bath for 1 h. Neutralized with Na2CO3 till effervescence ceases. Made up to 100 ml with water. 10 ml Fehling s A and B were taken in a conical flask and boiled. Methylene blue indicator was added and titrated with the sample taken in the burette till the brick red colour appears. 3.12. Test for phenol Standard was prepared by dissolving 250 mg gallic acid and 250 ml distilled water. Blank is prepared using 47 ml of distilled water added 1 ml phenol reagent with 50 ml 20% Na2CO3.1.4763 kg sample was taken and added 1 ml and 46 ml distilled water and 1 ml folin reagent with 50 ml 20% Na2co3 solution. Absorbance at 760nm was recorded 3.13. Test for protien Briefly, 1.2 g of the sample was weighed and transferred to a 500 or 800 ml kjeldhal flask. To this 0.45 g CuSO4, 15 gm K2SO4/Na2SO4 and 40 ml concentrated H2SO4 was added. Flask was heated gently at low flame until the initial frothing ceases. Continue heating for about an hour or more until the colour of the digest is pale blue. Cool the digest and 200 ml of water were added slowly. Cool and added a piece of granulated zinc or anti bump granules and carefully pour down the side of the flask sufficient sodium hydroxide solution to make the contents strongly alkaline before mixing the acid and alkaline layer. Connect the flask to distillation apparatus. To the condenser fit a delivery tube which dips just below the surface of the pipette volume of standard and contained in a conical flask receives. Mixed the contents of the digestion flask and boiled until 150 ml have distilled in to the receiver. 5 drops of methyl red indicator was added and titrated with 0.1 N NaOH solutions. 3.14. Test for minerals Stock solution was prepared by pipetting 1 ml of 9 element standard in to a 100 ml standard flask and make up to using water. Working standards are prepared from stock solution by appropriate dilution so that all the standards fall within the linear range of the element of interest. Mixed standards of all elements of interest were prepared. 5.0 ml concentrated HNO3, 0.5 ml concentrated HCl and 1.0 ml H2O2 was added and allow 15 minutes self digestion. Tighten the cap and kept for digestion in the MDS. After digestion quantitatively transfer the contents in to 50 ml tube and make up to 50 ml using extra pure water. Digested solutions were determined by ICP MS. 209
3. Results and discussion Preliminary phytochemical screening of Sechium edule consist of primary metabolite, carbohydrate and protein and secondary metabolites, saponin, phenol, flavonoids, steroids, tannin, terpenoids, coumarin. The medicinal importance of tannins, saponins, flavonoids, alkaloids, steroids and which are components of traditional herbal preparation used in managing various ailments has been reported (Okoegwale et al., 2001). Flavonoids are known for their antioxidant activity, and hence they help to protect the body against cancer and other degenerative disease such as arthritis and type II diabetes mellitus. Steroids are administered mostly to athletes to increase muscles and bonesynthesis. Saponins are expectorants, cough suppressants and administered for hemolytic activities (Sofowora 1993; Okwu 2005; Kotzekidou et al., 2008; Ejele 2010; Ugbogu et al., 2010). Tannins are well known for their antioxidant and antimicrobial properties as well as for soothing relief, skin regeneration, as antiinflammatory and diuresis. Table 1. Preliminary phytochemical analysis of Sechium edule (Jacq.) Swartz. Tests Methanolic extract Carbohydrates Molisch s test + Benedict s test + Fehling s test + Proteins Biuret test + Nitric acid test + Alkaloids Dragendroff s test Wagner s test Marqui s test Mayer s test Flavanoids NaOH test + H2SO4 test + Phenol FeCl3 + Steroids Liebermann Burchard test + Coumarins FeCl3 test + Fluorescence test + Cardiac glycosides Keller kiliani test Tannins FeCl3 test + Terpenoids Salkowski test + note: (+) Positive Test, ( ) Negative Test In this study the selected mineral constituents iron, calcium and zinc and manganese of Sechium edule revealed that their concentration is comparatively varied. Calcium (Ca) content was high as compare to other minerals. Sechium provided maximum 27.89 ppm calcium. Second abundant mineral was iron (Fe). Manganese was also provide 3.61 ppm. Minimum amount was provided in zinc (1.39 ppm). The Sechium edule contain vitamin C. Vitamin C is very important in the daily food as it has a variety of roles in the life processes. The carbohydrate content in Sechium is 5.19%.total sugar and protein content is very little amount. In short form the result it is clear that Sechium edule (Jacq.) Swartz. 210
Contain valuable phytochemicals like carbohydrate, protein, flavonoids, phenol, steroids, coumarins, tannins, terpenoids and saponin and many important minerals. Table 2. Nutrient analysis of Sechium edule (Jacq.) Swartz. S.No Parameters Results 1 Total sugar 2.74% 2 Phenol 0.0048% 3 Protein 0.94% 4 Vitamin C 0.16% 5 Carbohydrate 5.19% 6 Iron 10.67 ppm 7 Manganese 3.61 ppm 8 Zinc 1.39 ppm 9 Calcium 27.89 ppm 4. Conclusion The phytochemical screening of fruit extract of Sechium edule showed the presence of saponin, phenol, flavonoids, steroids, tannin, terpenoids, coumarin. The methanolic extract had significant quantity of nutrients. Indicating that the fruit of Sechium edule is phytochemical rich and carbohydrate is also present which are used to prevent chronic disease like cardiovascular disease, metabolic syndrome, high blood pressure and diabetes. Sechium edule (Jacq.) Swartz is one of the underutilized tropical vegetable commonly called as chow chow grows abundantly without much care and attention. The phytochemical and nutrient contents of the underutilized vegetable, Sechium edule (Jacq.) Swartz serve as supplements for food and also have the potential to improve the health status of its users as a result of the presence of various compounds vital for good health. So we have to popularize this vegetable and exploit its potential. Conflict of interest statement We declare that we have no conflict of interest. References 1. Aberoumand A, Deokule SS. (2009). Studies on nutritional values of some wild edible plants from Iran and India. Pakistan Journal of Nutrition, 8(1), 26 31 2. Cushnie TPT, Lamb AJ. (2005). Antimicrobial activity of flavonoids. International Journal of Antimicrobial Agents, 26 (5), 343 356. 3. Ejele AE. (2010). Effect of plant extracts on the microbial spoilage of Cajanus cajan. International Journal of Tropical Agriculture and Food Systems, 4(1), 46 49. 4. Kotzekidou P, Giannakidis P, Boulamatsis A. (2008). Antimicrobial activity of some plant extracts and essential oils against food borne pathogens in vitro and on the face of inoculated pathogens in chocolate. LWT Food Science and Technology, 41, 119 127 211
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