Effects of Red Jujube Polyphenol Precoating on Grape Storage Quality
Grapes were used as experimental materials,grape fruits were coated with different concentrations of red jujube polyphenol solutions at 0.5%,0.7%,0.9%and 1.1%concentrations.The sensory evaluation,decay rate,weight loss rate,soluble solid content,titratable acidity,ascorbic acid content,oxidoreductase and polyphenol oxidase activity of the grapes were measured every 48 hours,the effects of different concentrations of red jujube polyphenols on the quality of grape post harvest storage were studied,in order to provide reference for grape post harvest storage.The results showed that compared with the control group,the coating group could significantly reduce the decay rate and weight loss rate of grapes during storage,and significantly reduce the respiratory intensity of grapes in the early stage of storage,thereby inhibiting the reduction of titratable acid,soluble solids,and ascorbic acid content.The titratable acid,soluble solid content,and ascorbic acid content of group D coated with film were 0.208%,4.31%and 3.49 mg·(100g)-1 higher than those of the control group after 16 days,respectively;the activities of polyphenol oxidase and oxidoreductase in the coating group were effectively inhibited compared with the control group,group B and group A were particularly significant in terms of coating.Therefore,the precoating treatment of red jujube polyphenols could effectively maintain the internal and external quality of the fruit,made it suitable for post harvest storage of grapes.