However, it contains anti-nutritional factors, such as trypsin inhibitor, goitrin, soybean antigen and so on [6,7]. The anti-nutritional factors may be defined as those ...
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Journal of Chemical and Pharmaceutical Research, 2015, 7(11):494-498
Research Article
ISSN : 0975-7384 CODEN(USA) : JCPRC5
Effect of germination process on some anti-nutritional factors, proximate composition, mineral and vitamin contents of soybean Grace Oluwatoyin Ogunlakin*, Sogo James Olatunde, James Abiodun Adeyanju and Olanike Oyindamola Leke Department of Food Science and Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo State, Nigeria _____________________________________________________________________________________________ ABSTRAST This study was undertaken to evaluate the effects of germination process on proximate composition, some minerals, vitamins and anti-nutritional factors of soybean. For this purpose, soybeans were germinated for 2, 3 and 5 days respectively after which the samples were evaluated for proximate, anti-nutritional factors, mineral and vitamin content. There was general decrease in the proximate composition (moisture, protein, fats, and crude fibre) of the samples as germination days increased with the exception of ash and carbohydrate which increased with corresponding days of germination. Minerals and vitamins where also increased with increase in germination days. The results showed that anti-nutritional factors (phytic acid, tannins, trypsin inhibitors and oxalates) evaluated decreased as germination days increased. These findings show that germination process could significantly affect anti-nutritional factors, vitamins, minerals and proximate content of soybean. Germination could be effectively used to reduce stress factor in soybeans as well as to increase the contents of both minerals and vitamins. Key words: Germination, Proximate composition, Minerals, Vitamins, Anti-nutritional factors. _____________________________________________________________________________________________ INTRODUCTION Soybean (Glycine max (L) Merrill) belongs to the family leguminoisae and sub-family papilionnideae. It is a cheap and good source of protein for both animals and human consumption [1,2]. Soybean contains about 40% protein which is almost twice of other pulses and high quality of oil of about 20% [3]. It is an excellent source of high quality protein, less saturated fat with no cholesterol and a great amount of dietary fibre [4]. Soybean is a good source of minerals and vitamins like calcium, iron, phosphorus, zinc, magnesium, thiamin, riboflavin, folacin [5]. However, it contains anti-nutritional factors, such as trypsin inhibitor, goitrin, soybean antigen and so on [6,7]. The anti-nutritional factors may be defined as those substances generated in natural food stuffs by the normal metabolism of species and by different mechanisms (e.g. inactivation of some nutrients, diminution of the digestive process, or metabolic utilization of feed) which exert effects contrary to optimum nutrition [8]. Also, according Yin et al. [9], most of anti-nutritional factors have a negative effect on digestion, absorption, efficiency of utilization and metabolism of protein and growth rate in simple stomach farm animals fed on raw or poorly processed (undercooked) soya bean meal. It is only when attention is given to removing anti-nutrients from foodstuff can the full potential of those foods being realized.
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Grace Oluwatoyin Ogunlakin et al J. Chem. Pharm. Res., 2015, 7(11):494-498 ______________________________________________________________________________ Though, it has been reported that major anti-nutritional factors in soybeans such as trypsin inhibitors and lectins are heat labile and can be destroyed with heat [9]. But the thermal treatment process could also destroy other essential nutrients in soybean. It has also been reported that there is still low-levels of anti-nutritional factors such as phytoagglutinin after heat treatment [10]. There is therefore need to consider alternative methods of removing antinutrient which are non-thermal and cost effective. One of such methods is germination. Therefore, the present study was designed to study on the effect of germination process on some anti-nutritional factors, vitamins and proximate composition of soybean. These results would further confirm germination as an authentic method of anti-nutrient removal and its impact on vitamins, and proximate composition of soybean. EXPERIMENTAL SECTION Materials Soybean seeds were purchased from Bodija Market in Ibadan. Sample preparation The soybean was sorted, weighed and steeped (soaking in water for germination) for 12 hours with the addition of 1ml hydrogen peroxide to prevent rotten/fermentation. After 12 hours it was drained, sprayed thinly on bed for 5 days, it was sprinkled with water three times a day for those days while the un-germinated sample was kept as reference sample. The germinating samples were kilned to stop germination process on day 2, 3 and 5 respectively, and allowed to equilibrate with the atmospheric humidity. The sprouts were dehulled and cleansed, after which they were dried and ground into powder before analysis was carried out. Proximate analysis The moisture, ash, protein, fat, fibre and carbohydrate contents were determined using standard method [11]. Determinations of vitamins and minerals Riboflavin, thiamine and niacin were determined using standard method [11] while ascorbic acid was determined according to the method of Pearson [12]. The mineral elements (calcium, phosphorus and iron) were determined using the analytical method of determining mineral constituents of food products [13]. Determination of anti-nutritional factors Phytic acid, trypsin inhibitors, tannin and oxalates were determined using standard method [11]. RESULTS AND DISCUSSION Proximate composition of the samples The results of the proximate composition of the various flour blends are presented in Table 1 which showed significant difference (p
