Effect of pulse electric field pretreatment on the cold storage quality of loquat (Eriobotrya japonica Lindl. Cv. Guizhoupipa)

Loquat fruit is highly susceptible to chilling injury during low-temperature storage, leading to tissue browning and quality deterioration, which severely limits its postharvest commercial value. This study investigated the efficacy of pulsed electric field (PEF) pretreatment in maintaining the quality of cold-stored loquat fruit at 1°C. The results showed that PEF pretreatment exerted dose-dependent effects on fruit quality preservation. Treatment at 0.3 kV/cm effectively suppressed browning and reduced the decay rate to 23.20 ± 2.44% after 16 days of storage, significantly lower than that of the control (46.93 ± 1.14%). Additionally, this treatment better maintained fruit firmness, minimized weight loss, and preserved higher vitamin C content, thereby improving both visual and nutritional quality. However, quality declined at a higher PEF intensity of 0.5 kV/cm, likely due to excessive electroporation-induced cellular damage. During early storage, the 0.3 kV/cm treatment increased total phenolic content by 72.36% and sustained higher total flavonoid levels (0.84–0.99 mg/g) throughout storage. Concurrently, polyphenol oxidase (PPO) activity decreased to 33.94 ± 0.66 U/g by day 16, while peroxidase (POD) activity remained consistently lower than in the control. The elevated accumulation of antioxidant compounds, coupled with the inhibition of key browning-related enzymes, appears to be the primary mechanism by which PEF alleviates chilling-induced browning. In conclusion, PEF pretreatment offers an effective strategy for extending the shelf life of cold-stored loquat fruit and shows potential for application in other chilling-sensitive fruits.