Roles of ROS in physiological, microbial and metabolomic alterations of fresh–cut sugarcane under red and blue light irradiation

Effects of red and blue light treatment on physiological quality, microbial loads, redox status and metabolomics profiles of fresh-cut sugarcane in vacuum and plastic packages were investigated during 15 d storage. The results showed that light synergistic vacuum treatment delayed the decrease of pH and the increase of respiration rate and microbial loads, enhanced antioxidant capacities and related enzymes activities. Light treatment was beneficial to 1 O 2 generation, but had opposite effects on O 2 − , H 2 O 2 and malondialdehyde. O 2− and H 2 O 2 was negatively associated with CAT, sucrose, fructose, glucose, 2-oxoglutaramate, liquiritigenin and dihydromyricetin, positively with PPO and malondialdehyde. Only phenylacetaldehyde exhibited a negative correlation with 1 O 2 . The biosynthesis of sugars, amino acids and flavonoids were the principal metabolite pathways corresponding to oxidative stress in fresh-cut sugarcane. It could be concluded that the concentration of ROS, especially O 2− and H 2 O 2 , should be appropriate to kill bacteria and retain the quality of fresh-cut sugarcane.