Effect of lipoxygenase‐induced oxidation on molecular structure and digestive properties of arachin and conarachin

Lipid oxidation products can affect the molecular structure and digestibility of peanut protein isolates. Lipid-oxidizing systems (LOS) is a simulation system which uses oxygen-free radicals generated by the reaction of linoleic acid and lipoxygenase as oxidants.The simulation system was established to mediate oxidation of arachin or conarachin. Degree of oxidation (DOX) of peanut protein isolates (PPIs) was measured as quantity of LA to generate LOS. This study analyzed the effect of lipid oxidation-derived free radicals on the molecular structure and digestive properties of arachin and conarachin and observed substantial changes in carbonyl content, total sulfhydryl content, and number of disulfide bonds as quantities of LA increased, thus indicating significant oxidation of two proteins. Further, it was found that arachin was more stable than conarachin in a LOX-catalyzed oxidizing system. When the amount of LA was 3 and 5 ml, the maximum surface hydrophobic characteristic values of arachin and conarachin reached the maximum, which were 235 ± 10 and 349 ± 13, respectively. This study laid a theoretical foundation for the application of peanut protein in food products. Practical applications peanut protein has generated interest because it is the best source for the wall material for the preparation of nanoparticles and microcapsule particles due to its good biocompatibility and biodegradability, The structure-activity relationship between arachin and conarachin is of great guiding significance for the improvement of peanut protein molecular modification and functional properties.This study laid a theoretical foundation for the application of peanut protein in food products.