Temporal dynamics of enzyme-driven polyphenol modifications in stored eggplant (Solanum melongena L.)

The Postharvest handling of eggplants (Solanum melongena L.) significantly affects their metabolic profile and enzymatic response. Limited information is available regarding the enzymatic or oxidative degradation of polyphenols in eggplants and their free radical scavenging potential (FRSP) under variable storage temperature. The present study was conducted on postharvest storage of eggplant fruits under ambient (AS) and cold storage (CS) conditions. Polyphenol content and degradation products were evaluated in eggplant fruits using biochemical methods, whereas the FRSP was analysed using DPPH, ABTS, and FRAP assays. Polyphenol oxidase (PPO) and peroxidase (POD) were key enzymes involved in the polyphenol degradation of eggplant. PPO (18.4–53%) and POD (9.8%) activities were reduced under cold storage as compared to the ambient storage conditions. Oxidative enzyme activities and FRSP were correlated to the phenolic content under AS and CS conditions. Storage of eggplants at CS conditions reduced the phenolics degradation significantly.