Soybean (Glycine max (L.) Merrill) is one of the most studied vegetables, due to its use as sources of edible oil and protein for human and animal feeding. The presence of trypsin inhibitors in soy grain restrict its utilization and requires heating to improve the nutritional quality. However, excessive heating may reduce the protein quality. Soybean cultivar BR-36 containing normal content of trypsin inhibitors and soybean cultivars (BRM 95 5297 and BRM 95 5262) with low content of trypsin inhibitors were used. Soybean flour with 10 and 16% moisture were heated at 95°C in five different retention times ( 15, 25, 50, 75 and 100 min) and, then, the respective kinetic inactivation parameters for the trypsin inhibitors and protein insolubilization were estimated. By the first-order reaction for inactivation of trypsin inhibitor and protein insolubilization, the rate constant of trypsin inhibitor reaction incresead, resulting in decreasing heating time of BRM 95-5297 and BRM 95-5262 cultivars when compared to BR-36 cultivar. The increase of 6% moisture in flours also increased the rate constant of reaction for inactivation of trypsin inhibitors and for protein insolubilization.
antinutritional factors; heating treatment; kinetics parameters; protein insolubility; retention time
