Internal browning (IB) is a main problem of Queen pineapple during cold storage. The effects of exogenous salicylic acid (SA) or abscisic acid (ABA) on IB alleviation of the pineapple during cold storage were investigated. ‘Sawi’ pineapples were peduncle-infiltrated with 2 mM SA or 380 µM ABA for 3 d at 13°C followed storage at 13°C for 14 d. IB incidence and IB-related factors including lipid peroxidation, antioxidant capacity and antioxidant enzymes activities of the tissue adjacent to core were investigated after storage for 7 and 14 d followed by 2 d at room temperature (RT). Both SA and ABA treatments obviously alleviated IB development. ABA lowered TP content, MDA accumulation and the activities of LOX, PAL and PPO and induced POD activity. SA lowered PAL and PPO activity, delayed LOX activity and MDA increase, enhanced phenols, antioxidant activity and both antioxidant enzyme yields. Both ABA and SA peduncle infiltration alleviated IB incidence of Queen pineapple during cold storage. Although ABA could reduce the IB incidence better than SA, due to the efficiency of lower reactions of browning-related enzymes and lipid peroxidation, exogenous SA application might be a better choice for commercial use. Abbreviations: Total phenols (TP), Malondialdehyde (MDA), Lipoxygenase (LOX), Phenylalanine ammonia lyase (PAL), Polyphenol oxidase (PPO), Peroxidase (POD) and Internal browning (IB)

The purpose of this study was to investigate the effects of salicylic acid (SA) dips incorporated with ultra violet-C (UVC) irradiation on postharvest quality of longan fruit cv. ‘Dor’ during refrigerated storage at 10°C. The longan fruit were dipped in SA solution at the concentration of 0, 1.0, 2.0 and 3.0 mM before irradiated with 6.6 kJ m-2 UVC. Physicochemical quality attributes including peel colour, taste attributes, fruit decay, sensorial qualities and bioactive compounds were monitored. SA dips incorporated with the UVC irradiation maintained the outer peel lightness (L*), total ascorbic acid (TAA) content and crispness score of flesh as well as lowered colour difference (∆E*) value of outer peel and the reduction total antioxidant capacity (TAC) of the flesh during storage. All treatments did not affect the fruit taste attributes including total soluble solids (TSS), total acidity (TA) and TSS/TA ratio. The fruit dipped with 2.0 and 3.0 mM SA incorporated with the UVC irradiation effectively delayed the fruit decay as well as inhibited off-flavour. The fruit dipped with 2.0 mM SA incorporated with UVC irradiation showed the highest acceptability score and also enhanced the activity of antioxidant enzymes such as ascorbic acid peroxidase (APX), superoxide dismutase (SOD) and catalase (CAT).