Effects of tree-spray of liquid calcium compound on the changes in cell wall components, cell wall hydrolases, and cell wall structure during cold storage of non-astringent persimmon fruits

摘要

An experiment was conducted to study the effects of tree spray of liquid calcium compounds (LCC) extracted from oyster shells on the fruit quality, cell wall components and structure, and cell wall hydrolases in persimmon cv. Fuyu fruits during 60 days of cold storage. The calcium content of flesh and cell wall was maintained at high levels in LCC-sprayed fruits. Pectin content, ethylene production, and respiration showed no difference between LCC-sprayed and untreated fruits. There was no difference in alpha and beta-galactosidase activities at harvest, but were lower in stored LCC-sprayed fruits. Fruit firmness was significantly higher in treated fruits than non-sprayed fruits at harvest and even after 60 days of storage. The acidity, soluble solids, and total sugars were unaffected. An electron microscopic study revealed severe degradation of middle lamella during storage of untreated fruits, while LCC-sprayed fruits showed a relatively sound structure.