Improving postharvest quality and antioxidant capacity of sweet cherry fruit by storage at near-freezing temperature

To improve postharvest quality of sweet cherry, the effect of near-freezing temperature (NFT) storage was evaluated by analyses of postharvest characteristics, biological compounds and antioxidant property. The fruit were stored at 5 degrees C, 0 degrees C and NFT (determined by biological freezing curve) respectively. NFT extended the longest storage period (up to 100 d) and maintained the consumable and better sensory quality. NFT storage delayed the senescence by suppressing respiration rate, softening, malondiadehyde accumulation and decay rate. Compared to 0 degrees C storage, the decay rate of fruit stored at NFT was approximately 4 similar to 8-fold lower at the end of storage and shelf-life. NFT also reduced weight loss and biological disorder (such as pitting and pedicel browing) during sweet cherry storage. Moreover, NFT delayed color changes and improved the levels of soluble solids content (SSC), titratable acidity, ascorbic acid, total phenolic compounds, total flavnoids and total anthocyanins in sweet cherry. The SSC in fruit at NFT was about 1.2-1.4 fold higher than that of 0 degrees C in both cultivars sweet cherry during shelf life after 80 days of cold storage. Additionally, NFT storage also enhanced antioxidant property and delayed the peak value of antioxidant capacity in fruit. These results suggested that NFT storage could be considered as a preservation method for improving postharvest quality and antioxidant property of sweet cherry fruit.