EFFECT OF SOAKING, COOKING AND CRUDE ALPHA-GALACTOSIDASE TREATMENT ON THE OLIGOSACCHARIDE CONTENT OF COWPEA FLOURS

The effects of soaking, cooking and crude alpha-galactosidase treatment on the level of stachyose and raffinose present in cowpea flours were investigated. Soaking for 16 h resulted in an average reduction of 26.2 % for stachyose and 28.0 % for raffinose, while cooking for 50 min resulted in a reduction of 28.6 % for stachyose and 44.0 % for raffinose. On the other hand, treatment of cowpea flours for 2 h at 50-degrees-C with crude fungal preparations having an alpha-galactosidase activity equivalent to 64 units mug-1 protein, brought about a mean decrease of 82.3 % for stachyose and 93.3 % for raffinose. These results show that the enzyme treatment was more effective in removing the raffinose-family oligosaccharides and hence could be a useful technique for control of the flatulence-inducing activity of cowpea flours.