| Soybean protein, soybean triglyceride, soybean lipoxygenase and pancreatic lipase were mixed to prepare the soymilk model system according to the content of components and the enzyme activity in the real soymilk.The ferrous oxidation of xylenol orange assay and headspace solid phase microextraction-gas chromatography-mass spectrometry were used to determine the lipid hydroperoxides and volatile flavor substances.The results showed that lipoxygenase catalyzed the oxidation of triglyceride to produce lipid hydroperoxide equivalent to 3.958 mmol/L H2O2, and the total amount of produced volatile flavor substances was 43.80 mg/kg. When the triglyceride hydrolysate was as enzymatic substrate,the lipid hydroperoxide was equivalent to 52.243 mmol/L H2O2, and the total amount of produced volatile flavor substances was 668.42 mg/kg. The flavor substances of soymilk and model system in the same reaction condition were analyzed by principal component analysis, and the model system and three soymilk samples were concentrated in the similar areas of the score map. The flavor produced by the soymilk model system had a good similarity with the characteristic flavor of the real soybean milk. |
