Nutritive Quality of Whole Soybeans Heat-Treated in a Continuous Flow Processor

Abstract

Whole soybeans were roasted in a continuous particulate medium processor using salt as the heat transfer medium. Two levels of initial bean moisture content (13 and 23%) and three levels of initial salt temperature (225, 250 and 275°C) were used. The effect of heat treatment on trypsin inhibitor content and protein solubility was determined while employing three roasting residence times (15,30 and 60s) and four pre-cooling holding times of 0, 5, 10 and 15 min. It was found that at the higher levels of treatment, trypsin inhibitor destruction was sufficient for feeding, and protein solubility levels indicated that treatment was not excessive. The relationship between trypsin inhibitor and soluble protein levels was investigated and the results seem to suggest that the two may not be directly correlated.