Effects of roasting level on physicochemical, sensory, and volatile profiles of soybeans using electronic nose and HS-SPME-GC-MS

We applied oven-roasting on soybean in order to investigate their physicochemical, sensory, and volatile profiles using electronic nose and HS-SPME-GC-MS. Results revealed a temperature dependent kinetic on the physicochemical index except fat content. Roasting at 200 degrees C for 20 min decreased the protein dispersibility index about 38%; while, lipoxygenase and peroxidase were entirely inactivated. The primary heat sensitive amino acids were methionine, arginine, and cysteine. Electronic nose showed certain capacity to discriminate varying roasted soybeans. Out of 41 volatile compounds identified in soybean headspace, 2,5-dimethylpyrazine showed the highest abundance of 411.18 mu g/Kg. Regression model suggested the association of hexanal and aliphatic alcohols with beany flavor, while pyrazines, heterocycles, and furanoids showed a positive correlation with roasted flavor. The selected flavor markers can be used to predict the development of flavor in roasted soybeans. Our study emphasized the effect of roasting level on nutritive value and flavor profiles of soybeans.

Automated summary

The study found that the physicochemical properties of roasted soybeans are temperature-dependent, with primary heat-sensitive amino acids including methionine, arginine, and cysteine. The volatile compound 2,5-dimethylpyrazine showed the highest abundance, while the regression model indicated a correlation of hexanal and aliphatic alcohols with beany flavor, and pyrazines, heterocycles, and furanoids with roasted flavor.