Abstract: The α-galacto-oligosaccharides raffinose and stachyose are abundant in legumes such as soybean of a person lack α-galactosidase in the digestive tract. Human is unable to digest these sugars,resulting in flatulence. So,the non-digestible oligosaccharides(NDO) are the major cause for human flatulence. The use of α-galactosidase is promising as a means to overcome this problem,and to increase the consumption of soy products. In this study,recombinant coffee bean α-glactosidase prepared by our lab was used to hydrolyzing raffinose and stachyose. The change of soy oligosaccharides were detected before and after the enzyme treatment by TLC and HPLC. Based of the traditional processing technology of soybean products,a new technology of enzyme adding method was proposed.

Key words: soy oligosaccharides； flatulence； recombinant &alpha, -galactosidase；