Combination of EGCG and CPPU Treatment Alleviates Pericarp Browning by Boosting Antioxidant Activity and Inhibiting Chlorophyll Degradation in “Feizixiao” Litchi After Harvest

ABSTRACT Fresh litchi fruit is highly susceptible to pericarp browning after harvest. The efficacy of combined epigallocatechin‐3‐gallate (EGCG) and fochlorfenuron (CPPU) treatment attributes in alleviating pericarp browning in litchi fruit were investigated. The results showed that the combined treatments effectively suppressed pericarp browning and mitigated the decline in chromaticity, chlorophyll, and phenolic content. The combined treatment inhibited the accumulation of malondialdehyde and hydrogen peroxide. Following the treatments, enhanced antioxidant activity was observed, as evidenced by increased DPPH radical scavenging capacity and improved reducing power. Enzyme activity assays revealed elevated levels of phenylalanine ammonia lyase (PAL) and catalase (CAT), but decreased activities of polyphenol oxidase (PPO), peroxidase (POD), and laccase (LAC). Furthermore, the expression of key genes related to chlorophyll degradation ( LcCLH2 , LcPPH , LcNYC1 , LcPPH1/2 , LcPAO , LcRCCR ) and enzymatic browning ( LcPPO , LcPOD , and LcLAC ) was effectively regulated. The combined treatment of EGCG and CPPU might provide a practical strategy by preserving chlorophyll and phenolic compounds, and enhancing antioxidant capacity to extend the storage life of green mature litchi varieties.