Bacterial volatile organic compounds supplemented with light-emitting diode lighting enhance antioxidant capacity and delay senescence in broccoli

Bacterial volatile organic compounds (BVOCs) are biological volatiles that can have a positive effect on the postharvest preservation of fruits and vegetables. In the present study, fumigation of broccoli with BVOCs released by Lysinibacillus fusiformis supplemented with light-emitting diode (LED) white light irradiation reduced the accumulation of reactive oxygen species in broccoli during senescence, enhanced the synthesis and accumulation of antioxidant substances, and increased antioxidant enzyme activity in stored broccoli. Compared to the control group (CK), transcriptomic and metabolic analyses of the composite treatment group (LED-BVOCs) on the 4 days of storage identified 3/1, 7/0, 1/1, 20/6, and 6/1 differentially expressed genes (DEGs)/differentially abundant metabolites in metabolic pathways related to ascorbic acid, glutathione, glucosinolate, polyphenols, and methionine, respectively, and there were 4 DEGs involved in the regulation of senescence during ethylene signal transduction. It is evident that LED-BVOCs treatment can effectively regulate the metabolic processes of antioxidants in broccoli during storage. Overall, the LED-BVOCs treatment improved the antioxidant capacity and reduced ethylene production in stored broccoli, thus delaying senescence. Our study provides new insights on the ability of using BVOCs as biopreservatives to improve the antioxidant capacity and delay senescence of broccoli during storage.