Highly effective inactivation of anti‐nutritional factors (lipoxygenase, urease and trypsin inhibitor) in soybean by radio frequency treatment

Radio frequency (RF) treatment at 27.12 MHz was employed to inactivate the anti-nutritional factors (ANFs), including lipoxygenase (LOX), urease and trypsin inhibitor to minimise deleterious effects caused by conventional hot-air heating. The effects of RF heating on the ANF activities, physicochemical properties and processing quality of intact soybean were investigated. The results revealed that ANF activities were effectively inactivated within 300 s by RF heating and inactivation rates of LOX, urease and trypsin inhibitor were 95.2% (270 s), 93.4% (285 s) and 89.4% (300 s), respectively. In addition, RF heating improved physicochemical properties and processing quality of soybean products when the trypsin inhibitor was inactivated. On the contrast, conventional thermal treatment significantly decreased functional properties and led to the formation of greater aggregates. Our results may provide a novel method to inactivate endogenous enzyme in crops without negative impact on processing quality.