Light exposure reduced browning enzyme activity and accumulated total phenols in cauliflower heads during cool storage

• Light exposure inhibited PPO and POD activities, thus reduced browning occurrence.
• Light exposure induced PAL activity and accumulated TP content.
• Light exposure delayed vitamin C deterioration during storage compared to darkness.
• Light exposure accelerated fresh weight loss during storage.

Effects of continuous light exposure (24 μmol m−2 s−1) on browning enzyme activity and total phenol (TP) content in fresh cauliflower heads were investigated during 7 d storage at 7 °C using darkness as the control. Results showed that light exposure inhibited polyphenol oxidase activity (PPO) by 26% and peroxidase (POD) by 16%, as well as lowering the browning index (BI) by 33%, compared to darkness, at the end of storage. Light exposure also induced 43%, 35%, and 20% increases in phenylalanine ammonia lyase (PAL) activity at 1, 3, and 5 d storage, respectively, thus accumulating 41% more de novo TP content than in darkness after 7 d storage. In addition, vitamin C content deteriorated during storage under both light and dark conditions, with light exposure preserving vitamin C content 30% more than in darkness. However, light exposure accelerated fresh weight loss, with the largest value of 1.8% at the end of storage.