Effect of natural fermentation on nutritional composition and anti-nutrients in soy-wara (a Nigerian fried soy-cheese)

Abstract

This study was carried to evaluate the effect of natural fermentation on nutritional composition and anti-nutrients in soy-wara. A total of 100 samples consisting of five treatments of 20 samples per each treatment were studied. Yellow soybeans were soaked and fermented for 24 hrs, 48 hrs, 72 hrs and 96 hrs respectively at 27±2oC with 0 hr as control. Fermented soybeans were used for soy-wara production and soy-wara samples were evaluated for nutritional (amino acid, vitamin and mineral profile) and antinutritional (phytate, tannin and trypsin inhibitor activity) qualities. Results of amino acids analysis showed that tryptophan, isoleucine, methionine, phenylalanine, leucine and lysine contents in the fermented soy-wara ranged from 3.49 to 6.75, 21.94 to 24.41, 20.60 to 23.98, 22.11 to 27.15, 33.16 to 36.51 and 24.16 to 26.27 mg/100 g respectively. The values of thiamine, riboflavin and niacin contents in the fermented soy-wara ranged from 1.60 to 1.87, 1.44 to 1.71 and 2.21 to 2.78 mg/100 g respectively. The mineral elements calcium, iron, potassium, sodium, phosphorus and magnesium contents in the fermented soy-wara ranged from 17.65 to 19.08, 6.94 to 8.41, 29.76 to 30.69, 8.31 to 9.42, 27.52 to 28.55 and 21.02 to 24.83 mg/100 g respectively. Soaking and fermentation reduced the tannin content from 115.64 to 43.26 mg/100 g; phytate content from 153.81 to 47.16 mg/100 g, trypsin inhibitor from 96.56 to 1.10 mg/100 g and protease inhibitor from 98.11 to 1.2 mg/100 g respectively. In conclusion, natural fermentation of the legume reduced anti-nutritional factors and improved the nutrient composition of the product.