Insight into the Oxidation Mechanism of Coconut Globulin by Atmospheric Cold Plasma Focusing on Side Chain Amino Acids

Atmospheric cold plasma (ACP), a novel non-thermal processing technology, generates active substances that stimulate protein oxidation in protein-based foods. Nevertheless, the precise mechanism through which ACP initiates amino acid oxidation on protein side chains remains ambiguous. This study primarily aimed to elucidate the mechanism of ACP-induced oxidation of coconut globulin, focusing on the process of amino acid oxidation. Analysis of protein oxidation products indicated a positive correlation between the extent of protein oxidation and the voltage and duration of ACP treatment. By analyzing the composition of amino acids and active ingredients, the study identified that the most significant changes amino acids were methionine, cysteine, and arginine, and center dot OH was the primary free radicals. The findings from oxidation kinetics and dynamic simulation indicated that center dot OH predominantly oxidized methionine, followed by L-cysteine and L-arginine. These results offer theoretical framework for understanding protein oxidation by ACP and suggest potential applications in protein-based food.