Effect of AAPH oxidation on digestion characteristics of seed watermelon (Citrullus lanatus Var) kernels protein isolates

Abstract Seed watermelon kernel is a typical complex food with high fat and protein contents. During storage and processing, it is often affected by various factors to undergo interactions between components, which lead to its quality change. In this experiment, seed watermelon kernels were used as research objects, and the effects of 2'-Azobis (2-amidinopropane) dihydrochloride (AAPH) on seed watermelon kernel protein isolates (WMP) were investigated. The structure and digestion characteristics of WMP after oxidation were studied. The results showed that with the increase of AAPH concentration (0.05-5 mol/L), WMP showed obvious aggregation, and its solubility decreased from 6.76 mg/mL to 9.59 mg/mL. The free sulfhydryl content of WMP was 18.24 mmol/g decreased to 11.25 mmol/g, α -helix decreased and β -sheet decreased in secondary structure, and its disulfide bond increased by 43.06 mmol/g from 39.57 mmol/g, enthalpy (ΔH) and denaturation temperature increased (T d ) ( p