Effect of Postharvest Dipping in CaCl_2 Solutions with Some Adjuvants on the Fruit Quality and Calcium Concentration of 'Fuji' Apples during Storage

摘要

The objective of this research was to extend storage periods by increasing calcium contents of 'Fuji' apple fruits. To achieve this, apple fruits were dipped in CaCl_2 solution containing adjuvants, then changes of fruit quality and calcium contents of apple fruits during storage at 3 - 5 °C were determined. CaCl_2 + wax treatment had more calcium contents in peel and flesh of apple fruits than CaCl_2, CaCl_2 + chitosan, and CaCl_2 + Ag treatments. In the determination of calcium form, water solublecalcium was the highest followed by exchangeable, HAc fraction calcium, and HC1 fraction calcium in all treatments. The treatment of CaCl_2 + wax which had the highest calcium contents in flesh also had the highest contents of physiologically active calcium such as water soluble and exchangeable calcium among treatments tested. Incorporation of adjuvants to CaCl_2 solution resulted in increase of calcium concentration in the cell wall showing the highest in CaCl_2 + wax among the treatments tested. Alltreatments of dipping application did not affect changes of potassium and magnesium concentrations in cell wall during storage. The degree of fruit firmness decreased during storage, but the application of CaCCl_2+ adjuvant retarded the decrease. The treatment of CaCl_2 + chitosan showed best results in keeping of fruit firmness among treatments. But dipping treatments did not show effectiveness in the contents of soluble solid and acid. The fruit weight decreased during storage, but the application ofCaCCl_2 + adjuvant slowed the rate by increasing calcium contents in the flesh.