Effect of preharvest calcium sprays on quality attributes and flesh browning of Zhonghuashoutao peach fruit

A non-melting flesh peach(Prunus persica L.cv.Zhonghuashoutao) was used to study the effect of preharvest spraying of calcium nitrate on fruit quality and flesh browning during storage.The results showed that the calcium content of Ca-sprayed fruit was increased significantly by 11.5% and 16.1% in peel and flesh,respectively.The flesh firmness was en-hanced by 7.8% in Ca-sprayed fruit,which maintained firmness for longer time during storage.However,the soluble solids content and titratable acidity were not influenced by the preharvest calcium sprays.The respiration rate of Ca-sprayed fruit was not restrained apparently,although the climacteric peak of fruit was delayed by one day.In addition,preharvest calci-um-spraying increased the content of total phenolics and polyphenol oxidase activity during the period of shelf life after cold storage,but the activity of lipoxygenase decreased significantly in Ca-sprayed fruit.The incidence and severe degree of flesh browning in calcium-sprayed fruit were not decreased apparently during the period of shelf life after stored for 4 weeks,but the browning rot was inhibited to a large extent.