Components Analysis and Flour Preparation of Tofu Whey

The aim of this study is to analyze the composition of tofu whey and spray-dry it into flour, so as to provide the basis for recycling this by-product of tofu manufacture. The results showed that tofu whey contain 3.19% of total solids, including 3.12% of soluble solids; 1.19% of carbohydrate, including 0.45% of reducing sugar, 0.26% of oligosaccharide and 0.48% of polysaccharide; 0.47% of protein; 0.49% of crude fat; 0.54% of total ash, including 0.048% of calcium, 0.042% of magnesium, 0.032% of sulfate ion and 0.060% of chloride ion; 0.20% of saponin and 0.04% of isoflavone. Tofu whey can be prepared into flour by the spray-drying method. The whey flour contained 5.55% of moisture, 23.60% of protein, 18.22% of polysaccharide, 13.67 % of oligosaccharide, 3.86% of saponin, 0.98% of isoflavone and 1.2% of calcium. This study suggested that tofu whey is rich in functional or nutritional ingredients and is worth recycling. Spray-drying whey into flour is a potential way for treatment of tofu whey, especially for those small and medium-sized factories.