A comparative evaluation of the macronutrient and micronutrient profiles of soybean-fortified gari and tapioca

Transcription

1 A comparative evaluation of the macronutrient and micronutrient profiles of soybean-fortified gari and tapioca Adelodun Lawrence Kolapo and Morenike Olayinka Sanni Abstract Background. and tapioca are storage-cupboard convenience foods obtained from the tubers of cassava (Manihot esculenta Crantz). They are important staples in Nigeria and many African countries where malnutrition is a major problem. is a quick-cooking food made from partly gelatinized starch and gari is a fermented, roasted, granular food made from cassava pulp. Objective. and tapioca are nutritionally inferior and need to be fortified. This paper reports the macroand micronutrient profiles of soybean-fortified gari and tapioca. Methods. and tapioca were fortified with soybean flour or soybean residue at 25% of dry weight. Standard methods were used for the determination of proximate parameters such as crude protein, fat, ash, carbohydrate and moisture content. All the samples were analyzed for phosphorus, calcium, magnesium, potassium, sodium, manganese, iron, copper and zinc. Results. Unfortified tapioca had significantly lower (p <.05) proximate values (protein: 0.31%; fat: 0.17%; ash: 0.34%) than unfortified gari (protein: 1.50%; fat: 1.56%; ash: 1.35%). The fortification of both gari and tapioca significantly (p <.05) increased the contents of crude protein, phosphorus, fat, and ash as well as all the monitored macro- and micronutrients. These values (%) increased from , , and for gari-soybean fortified gari; and , , and for tapioca to soybean fortified tapioca respectively. flour increased the nutrient content of the fortified gari and Adelodun Lawrence Kolapo is affiliated with The Polytechnic, Ibadan, Nigeria. Morenike Olayinka Sanni is affiliated with Ajayi Crowther University, Oyo, Nigeria. Please direct queries to the corresponding author: Adelodun Lawrence Kolapo, Biology Department, The Polytechnic, Ibadan, Nigeria; adelodunkolapo@yahoo.com. tapioca compared to soybean residue. Data from this study suggest that both soybean flour-fortified tapioca and soybean flour-fortified gari are effective means of meeting the daily requirements of minerals, protein, and energy. Conclusions. Both soybean flour-fortified tapioca and soybean flour-fortified gari could be used to fight macronutrient and micronutrient deficiencies, not only in Nigeria and other African countries where these two cassava products are staples, but also in other cassavaconsuming developing nations. Key words: Fortification, gari, macronutrient, micronutrient, Millennium Development Goals, tapioca Introduction Food fortification has been shown to be an important method of combating malnutrition across various sociocultural and economic groups, and it ensures adequate dietary intakes without changing cultural habits [1]. Clydesdale and Wierier [2] stated that food fortification is highly sustainable and fairly inexpensive and can be implemented relatively quickly. By adding whole foods such as soybeans, food fortification supplies a wide array of biologically available nutrients and should be preferred to piecemeal fortification through addition of individual vitamins and minerals. In the treatment of malnutrition, fortification of food with individual nutrients is always less desirable than the addition of whole foods. Malnutrition is a major problem facing developing countries, and micronutrient deficiency is an important feature of this hydra-headed problem. A recent report indicated that there was a high level of undernutrition among schoolchildren in Abia State, Nigeria, and that the diet was too low in micronutrients and too high in carbohydrates [3]. The Home-Grown Feeding and Health Program of the Federal Government of Nigeria 90 Food and Nutrition Bulletin, vol. 30, no , The United Nations University.

2 Evaluation of soybean-fortified gari and tapioca 91 is attempting to remedy micronutrient deficiency [Aminu and Begin*]. Ihekoronye [4] stated that the choice of food to be fortified depends on several factors: the food must be widely consumed, preferred by the population at risk, centrally processed, available and affordable. A potential candidate for fortification is cassava, a major staple food in Africa that is widely consumed as gari, lafun, fufu, and tapioca [5]. Raw cassava is toxic and must be processed before consumption to reduce the toxicity. Pamplona-Roger [6] noted that since the nutritional value of cassava is limited, it should not be the basis of any diet. Unfortunately, many Nigerians continue to consume cassava-based meals two or three times every day [5, 7]. Fortification of cassava with available legumes is therefore an urgent necessity, not only in Nigeria, but also in other cassava-consuming nations. Previous studies have described the methods of processing and the characteristics of soybean-fortified gari and tapioca, both of which are storage cupboard convenience foods [8, 9]. is made from partly gelatinized cassava starch, and is in the form of granules or pearls. It has to be cooked for 3 5 minutes with sweetener and milk before consumption. Cooked tapioca looks and tastes like oatmeal which has ~11% protein, but tapioca is nutritionally inferior with only 1 2% protein. is a fermented, roasted, granular food which can be consumed as processed or stirred into hot water and eaten with a of stew. also has 1 2% protein. Both gari and tapioca therefore need to be fortified with soybeans. The aim of this study is to describe the macronutrient and micronutrient profiles of soybean-fortified gari and tapioca. Processing of soybean-fortified gari and tapioca flour and soybean residue were prepared from soybean seeds as previously described by Sanni and Sobamiwa (fig. 1) [8]. residue was used on the same day it was prepared. The procedures for the production of soybean-fortified gari and soybeanfortified tapioca have been described previously [8, 9]. Three batches each of soybean-fortified gari and soybean-fortified tapioca were produced. Batch 1 was unfortified, whereas batches 2 and 3 were fortified with soybean residue and soybean flour, respectively. Previous reports showed that soybean fortification of tapioca and gari at the 25% level improved the protein content of the product adequately without significantly lowering its sensory attributes [8, 9]. Therefore all fortifications in the present study were done at 25% concentration on a dry weight basis. All tapioca products were made with, while gari products were made with both and TMS analysis All samples were analyzed for crude protein, phosphorus, calcium, magnesium, potassium, sodium, manganese, iron, copper and zinc. For analysis of nitrogen (crude protein) and phosphorus, the samples were first digested in a hot sulfuric acid solution with SeO 2 catalyst according to a method adapted from Novozamsky et al. [10], and the resulting solution was used for subsequent analyses. For phosphorus s Materials and methods Raw materials Boiling (20 min) Improved cassava cultivars TMS and were obtained from the Root and Tuber Improvement Programme (RTIP) of the International Institute of Tropical Agriculture, Ibadan, Nigeria. These improved varieties were chosen because they are early maturing and high yielding. The clones were collected from RTIP to ascertain the varieties, since market cassava tubers were often mixed and could no longer be classified. s were purchased from a local market, sorted, and cleaned manually. Drying Dry milling Dehulling Wet milling Filtration with muslin cloth * Aminu FT, Begin F. Addressing macronutrient deficiencies in school-age children through home-grown school feeding and health program (HGSF&HP): A review of policy and programmatic options. Paper presented at the 37th Annual Scientific Conference of the Nutrition Society of Nigeria, 8 11 November 2006, Abeokuta, Nigeria. flour residue milk FIG. 1. Processing of soybean flour and soybean residue. Source: Sanni and Sobamiwa [8]

3 92 A. L. Kolapo and M. O. Sanni analysis, the ascorbic acid method adapted from Murphy and Rilly [11] using an acid molybdate solution was employed. The popular Berthalot (indophenol reaction) method adapted from Searle [12] was used for nitrogen analysis, and the crude protein (NX6.25) was estimated. Other nutrients were determined after ashing in a muffle furnace at 500 C. The methods described by Jones and Case [13] and Hunter et al. [14] were used for the nutrient analysis. AOAC [15] methods were used for the determination of proximate characteristics such as fat content, ash content, and moisture content. Statistical analysis Data were expressed as means ± SD. The statistical significance of differences was assessed by analysis of variance. A two-tailed p value less than.05 was considered to indicate statistical significance. Values that were significantly different were separated by Duncan s multiple range test with the use of SPSS for Windows, version Results The proximate compositions of soybean-fortified gari, soybean-fortified tapioca, and controls are shown in table 1. Unfortified tapioca had significantly lower (p <.05) proximate values than unfortified gari. In all fortified samples, fortification significantly (p <.05) increased the crude protein, fat, and ash contents. flour appeared to be a better fortifier than soybean residue, since the proximate values of soybean flourfortified tapioca were significantly higher than those of soybean residue-fortified tapioca. There appeared to be a varietal influence on the proximate values, since the proximate values of gari made from cassava varieties TMS and were significantly different (p < 0.05). (table 1). On the other hand, there was no significant difference (p >.05) in the moisture contents of unfortified and fortified tapioca and gari. Table 2 shows the mineral compositions of unfortified gari, unfortified tapioca, soybean residue-fortified tapioca, soybean flour-fortified tapioca and soybean flour-fortified gari. After fortification, there was a TABLE 1. Proximate composition of unfortified and soybean-fortified tapioca and gari (per 100 g) residue-fortified, TMS Protein (%) 0.31 ± 0.0 e 5.94 ± 0.0 c ± 0.01 a 1.5 ± 0.00 d 1.00 ± 0.00 e 9.31 ± 0.02 b Fat (%) 0.17 ± 0.02 e 2.49 ± 0.02 c 5.45 ± 0.02 a 1.56 ± 0.02 c 1.49 ± 0.02 d 4.31 ± 0.02 b Ash (%) 0.34 ± 0.03 d 0.56 ± 0.04 c 1.41 ± 0.0 b 1.35 ± 0.0 b 1.64 ± 0.02 a 1.64 ± 0.01 a Carbohydrate (%) ± 0.8 a ± 0.44 c ± 0.56 e ± 0.9 a ± 0.08 b ± 0.05 d Moisture (%) 4.30 ± 0.2 a 5.11 ± 0.3 a 4.76 ± 0.4 a 3.61 ± 0.8 a 3.62 ± 1.7 a 4.83 ± 0.4 a Values are means ± SD (n=3). Values in the same row with different superscripts are significantly different (p <.05). TABLE 2. Mineral composition of unfortified and soybean-fortified tapioca and gari cassava residue-fortified, cassava cassava cassava TMS cassava cassava Calcium (%) 0.01 ± 0.00 f 0.02 ± 0.00 e 0.03 ± 0.00 c 0.02 ± 0.00 d 0.11 ± 0.00 a 0.04 ± 0.00 b Magnesium (%) 0.01 ± 0.00 c 0.01 ± 0.00 c 0.05 ± 0.01 a 0.02 ± 0.00 c 0.04 ± 0.01 b 0.03 ± 0.00 c Potassium (%) ± e ± d ± a ± b ± c ± a Crude phosphorus (%) 0.03 ± 001 c 0-05 ± 0.01 b 0.12 ± 0.01 a 0.06 ± 0.01 b 0.04 ± 0.00 bc 0.11 ± 0.01 a Sodium (ppm) 1.10 ± 0.29 b 1.93 ± 0.06 b 1.41 ± 0.20 b 5.24 ± 2.94 a 4.03 ± 0.37 ab 3.14 ± 0.08 ab Manganese (ppm) 2.24 ± 0.01 f 5.84 ± 0.00 e ± 0.05 b 8.11 ± 0.05 c 6.71 ± 0.01 d ± 0.71 a Iron (ppm) ± 0.08 f ± 0.11 d ± 0.00 d ± 0.17 c ± 1.24 e ± 0.8 a Copper (ppm) 1.79 ± 0.01 d 3.55 ± 0.00 c 6.26 ± 0.03 b 3.57 ± 0.02 c 3.54 ± 0.07 c 8.75 ± 0.05 a Zinc (ppm) 3.31 ± 0.15 f 7.80 ± 0.14 e ± 0.08 a 8.12 ± 0.05 d ± 0.16 c ± 0.0 b Values are means ± SD (n=3). Values in the same row with different superscripts are significantly different (p <.05).

4 Evaluation of soybean-fortified gari and tapioca significant increase (p <.05) in both the macronutrient and the micronutrient contents of soybean residuefortified tapioca. flour-fortified tapioca had an improved nutrient content in relation to protein, fat and all the minerals evaluated compared to soybean residue-fortified tapioca. Also, there were significant differences in the macronutrient and micronutrient contents of unfortified gari obtained from the two cassava varieties (table 2). It was noted that there was an increased difficulty in processing soybean residue-fortified products because of the rubbery texture of the mixture which made granulation difficult. Discussion In view of the nutritive qualities of both soybeanfortified gari and soybean-fortified tapioca, their use in famine relief in Africa and in other impoverished and malnourished populations of the world has been suggested [9]. The proximate values of fortified products in the present study are in agreement with our earlier reports [8, 9]. The crude protein content of soybeanfortified gari in the present study (9.31%) compared favorably with values of 7.7% to 12.3% reported earlier for soybean-fortified gari [9] and 6.5% to 16.4% for soybean-fortified maize tortillas [16]. Similarly, the fat contents of 2.4% to 4.6% reported for soybean-fortified tapioca [9] and 1.7% to 12.2% for soybean-fortified maize tortillas [16] compare favorably with the present values of 2.49% to 5.45%.The mineral contents of the fortified products in our study were also similar to those reported for soybean-fortified maize tortillas. The use of soybean flour instead of soybean residue in the fortification of tapioca appears to hold a greater promise, considering the nutritive qualities of the fortified products. This is probably due to the large nutrient loss that accompanies soybean residue production. Apart from the nutritional deficiency of soybean residue-fortified products, Sanni and Sobamiwa [8] reported an increased difficulty in processing soybean 93 residue-fortified products, which was also confirmed in the present study. In addition, when carbohydrate foods are fortified with legumes, especially oily legumes, bioavailability improves. This kind of fortification is cost-effective, with the added benefits of providing phytoestrogens and protecting against cancer [17]. For these reasons, fortification by soybeans is preferred for most people except for the very few who do not tolerate soybeans. Other methods of fortification include the addition of vitamins (e.g., vitamins A, B, and E) and minerals (e.g., calcium, iodine, iron, and zinc). These piecemeal additions are fraught with problems. When many products are fortified with the same nutrients and young children aged 1 8 years consume them, they may unwittingly exceed the tolerance level. Random fortification may also result in nutrient imbalance [17] or hypervitaminosis [18]. The Direction de l Alimentation et de la Nutrition Appliquée, Porto- Novo, Benin, authorized the enrichment of gari with iron, iodine, and vitamin A, although the quantities added were not stated [19]. -fortified gari and soybean-fortified tapioca should be recommended for vulnerable groups, especially children. The recommended dietary allowances (RDAs) of calcium, phosphorus, magnesium, iron, and zinc for children aged 4 to 8 years are 800, 500, 130, 10, and 10 mg per day, respectively. The RDA of protein is 24 to 28 g per day [20]. Data from the present study suggest that one 100-g portion of soybean flour-fortified tapioca would provide 30 mg, 120 mg, 50 mg, 5 mg, 1.5 mg, and 12.5 g of calcium, phosphorus, magnesium, iron, zinc, and protein, respectively, whereas an equal amount of soybean flour-fortified gari would supply 40 mg, 110 mg, 30 mg, 7 mg, 1.4 mg, and 9.3 g of the respective nutrients (table 3). This indicates that both soybean flour-fortified tapioca and soybean flour-fortified gari are potent means of meeting the daily requirement of phosphorus, magnesium, iron, zinc, and protein of children, especially given that children and adults may consume gari one to three times daily. In 2000, the world pledged through the Millennium TABLE 3. Recommended daily allowance (RDA) of nutrients for 4- to 8-year-old children and amount of nutrients obtainable from 100 g of unfortified and fortified tapioca and gari RDA cassava flourfortified, cassava flourfortified, Calcium (mg) Phosphorus (mg) Magnesium (mg) Iron (mg) Zinc (mg) Protein (g)

5 94 A. L. Kolapo and M. O. Sanni Development Goals (MDGs 1 and 2) to halve hunger and ensure universal primary education by the year It has since been recognized that school feeding programs could be a key to achieving these goals, because they bring many synergies that support each other. In response, the Federal Government of Nigeria launched a Home-Grown School Feeding and Health Program in 2005 [Aminu and Begin]. The results of the present study demonstrate that both soybean flourfortified tapioca and soybean flour-fortified gari are potential foods that could be used in such a program. This becomes more plausible because both products may be derived from locally sourced materials, thus making the Nigerian government s program similar to the Indonesian version described by Minarno.* Conclusions is a ready-to-eat convenience food, whereas tapioca is a quick-cooking food. -fortified gari and soybean-fortified tapioca are part of the ongoing efforts to curtail malnutrition, which is known to exacerbate * Minarno G. Example of a successful school feeding programme in Asia. Paper presented at the 37th Annual Scientific Conference of the Nutrition Society of Nigeria, 8 11 November 2006, Abeokuta, Nigeria. many diseases prevalent in Nigeria and Africa. These value-added products can also be produced to diversify the monotonous Nigerian diet and be a fortress against diseases. This study reveals that fortification of tapioca and gari with soybean flour produced a more beneficial effect, both in nutritional qualities and ease of processing. Both soybean flour-fortified tapioca and soybean flour-fortified gari are possible foods that could be used to fight macronutrient and micronutrient deficiencies in Nigeria and other African countries where cassava products are staples. Both are suitable for use in the fast-growing urban centers all over Africa and could be promoted in place of the empty-calorie drinks and fast foods that are continually advertised. Acknowledgments We express our sincere appreciation to The Polytechnic, Ibadan, for providing a conducive atmosphere for the work, Ajayi Crowther University, Oyo for providing the time and the Root and Tuber Improvement Programme (RTIP) of the International Institute of Tropical Agriculture for providing the cassava tubers. The data from this article was originally presented at a conference in Ghent, Belgium July 21 26, 2008: Global Cassava Partnership of the 21st Century for Genetic improvement. References 1. Mora JO. Issues in food fortification. Nutr Rev 1995; 4: Clydesdale FM, Wierier KL, eds. Fortification of foods. A report of the International Nutritional Anemia Consultative Group (INACG). Orlando, Fla, USA: Academic Press, Onimawo IA, Amabangwu KE, Eluwa MA. Nutritional status of school age children assessed by anthropometric and dietary methods. Niger J Nutr Sci 2006;27: Ihekoronye CN. Food fortification programs to eradicate iron deficiency anemia in the developing countries. Niger J Nutri Sci 2006;27: Sanni MO, Sobamiwa AO, Rosling H, Eyinla CM. The importance of cassava as sustenance for Ibadan small scale gari processors. Proceedings of the 6th Symposium of International Society for Tuber and Root Crop- African Branch(ISTRC_AB) 1995: Pamplona-Roger GD. Encyclopedia of medicinal plants. Madrid: Graficas Rewudas, Amadi BC. The impact of the invention of a mechanical gari processing machine on cultural aspects of gari consumption and cassava farming in Nigeria. Oxford Agrarian Studies 1983;12: Sanni MO, Sobamiwa AO. Processing and characteristics of soybean-fortified gari. World J Microbiol Biotechnol 1994;10: Kolapo AL, Sanni MO. Processing and characteristics of soybean-fortified tapioca. J Women Tech Educ 2005; 4: Novozamsky I, Houba VJG, Van Eck R, van Vark W. A novel digestion technique for multi-element plant analysis. Commun Soil Sci Plant Anal 1983;14: Murphy J, Rilly J. A modified single solution method for the determination of phosphate in natural waters. Anal Chim Acta 1962;27: Searle PL. The Berthalot or indophenol reaction and its use in analytical chemistry of nitrogen. Analyst 1984;109: Jones JB Jr, Case VW. Sampling, handling and analyzing plant tissue samples. In: Westerman RL, ed. Soil testing and plant analysis, 3rd ed. SSSA Book Series No. 3, SSSA, Madison, WI. 14. Hunter RC, Halverson TL, Anderson RD. Quality assurance for plant tissue analysis by ICP-AES. Commun Soil Sci Plant Anal 1984;15: AOAC. Official methods of analysis, 14th ed. Washington, DC: Association of Official Analytical Chemists, Obatolu VA, Okoruwa A, Iken JE. Improvement of home-made maize tortilla with soybean. Int J Food Sci Technol 2007;42: Tijani J, Olanrewaju BJ. The Food Fortification Initiative in Nigeria an overview. J Women Tech Educ 2005; 4: Davis A. Let s eat right to keep fit. London: Harper Collins, Yessoufou A. Improved gari. Spore Magazine 1994;52: Wardlaw GM. Perspective in nutrition. New York: McGraw-Hill, 1999.