Effect of combined cell wall degrading enzyme treatment on the total dissolved solids and sugars of soymilk

Abstract

Soymilk from different varieties of soybean was treated with combinations of cell wall hydrolyzing enzymes (glucanase, cellulose, arabanase, hemicellulase and xylanase). Treated samples and control were evaluated for Total Dissolved Solids (TDS) and different sugars (glucose, raffinose, sucrose, fructose, xylose, maltose, lactose, stachyose, starch, galactose, cellulose) using HPLC. Mean TDS of all enzyme-treated soymilk samples (235.8-268.3 ppm) was significantly (p≤0.05) higher than the control (167.8 ppm), it also increased significantly (p≤0.05) after sterilization. Sugars
present in the enzyme-hydrolyzed soymilk were significantly (p≤0.05) different from the control. Sucrose content was depleted after enzyme treatment. The change in content of glucose, xylose, fructose, maltose, raffinose, starchyose had high correlation with TDS. Possible chemical modification of sugars impaired their detection despite increases in TDS. Use of TDS for rapid monitoring of enzyme hydrolyses of soymilk cell-wall sugars is feasible.