Effects of combined treatment with chitosan, d-isoascorbate sodium and γ-aminobutyric acid on enzymatic browning and flavor quality of Paojiao

Abstract

In this study, non-targeted metabolomics and GC-MS were used to investigate the effect of anti-browning treatment (adding 0.20% chitosan, 0.15% d-isoascorbate sodium and 0.10% γ-aminobutyric acid) on enzymatic browning and flavor of Paojiao, respectively. The results showed that compared with untreated Paojiao, the browning index of treated Paojiao was significantly reduced (P < 0.01), and the activities of phenylalanine ammonia lyase (PAL), peroxidase (POD), and polyphenol oxidase (PPO) were inhibited. In total, 944 metabolites were detected, including 59 differential metabolites. KEGG enrichment results showed that the anti-browning treatment mainly inhibited the browning of Paojiao through arachidonic acid metabolism and phenylpropanoid biosynthesis. Furthermore, the anti-browning treatment increased the richness of the flavor components of Paojiao, especially the esters. Overall, the anti-browning treatment could effectively inhibit the browning of Paojiao and improve its flavor, thereby providing a theoretical reference for the production and processing of high-quality Paojiao products.