Effect of O-Phenyl Phenol Coating on Storage Quality of Postharvest Gonggan Citrus

In order to extend the storage time of Gonggan citrus and explore the preservation effect of o-phenyl phenol (OPP) combined with wax coating on postharvest Gonggan citrus fruit, Deqin Gonggan citrus fruit was used as test material to study effects of 0.2% OPP combined with wax coating on quality of postharvest Deqin Gonggan citrus fruit stored at room temperature, and decay rate, hardness, titratable acidity (TA), total soluble solids (TSS), ascorbic acid (V_C), cell membrane permeability, malondialdehyde (MDA), superoxide dismutase (SOD) and catalase (CAT) were measured during the storage time. The results showed that controlled fruit began to rot after 6 days of storage and fruit treated with 0.2% OPP combined with wax coating began to rot after 12 days of storage, and decay rate of treated group was obviously slower than the controlled group during anaphase storage, as markedly extending storage time of postharvest Gonggan citrus at ambient temperature (P<0.05). Compared with the controlled fruit, the fruit treated with 0.2% OPP combined with wax coating maintained higher contents of TSS, TA and V_C. The treatment with 0.2% OPP coating obviously retarded fruit softening, reduced loss of water in fruit and kept higher hardness of fruit during storage. Furthermore, the result also indicated that the treatment with 0.2% OPP effectively maintained higher SOD and CAT activities of Gongan citrus fruit during latter stage of storage, reduced MDA accumulation and delayed increment of fruit cell membrane permeability during storage compared with the control, thus, efficiently delayed quality deterioration of postharvest Gonggan citrus fruit during storage at room temperature. Therefore, the treatment with 0.2% OPP combined with wax coating could be used as an effective way to preserve the freshness of gonggan citrus fruit after harvest.