Regulation of carotenoid synthesis and chlorophyll degradation in mangoes by red visible light irradiation during storage

This study reveals the mechanism by which red light (RL, 655 nm) regulates mango pigmentation during storage. Specifically, RL triggered rapid chlorophyll degradation, reducing chlorophyll a and b levels by 29.17 % and 47.62 % respectively at 3 d compared to control. It substantially boosted β-carotene synthesis, resulting in 191.63 % higher β-carotene and 238.21 % more violaxanthin myristate by 9 d. Additionally, activities of phytoene synthase (PSY) and phytoene desaturase (PDS) peaked earlier at 5 d in the RL group, achieving respective activities of 3.32 × 10 3 U/L and 2.29 × 10 3 U/L, respectively. These results demonstrate results demonstrate that early RL-induced chlorophyll removal initiates the β-carotene biosynthetic route, promoting pigment deposition and accelerating peel coloration. Our findings thus offer not only a mechanistic explanation but also a viable technological strategy for improving postharvest mango quality through non-chemical means.