A Combination of heat treatment and chitosan coating delays ripening and reduces decay in "Gala" apple fruit

Apples (Malus domestica Borkh. cv. Gala) were heat-treated at 38C for 4days (heat treatment [HT]) before or after coated with 1% chitosan (CTS). Following treatment, apples were stored at 0C for 8weeks and 20C for 7days as shelf life. The effectiveness of the combined treatments on the ripeness, quality and decay development caused by Penicillium expansum and Botrytis cinerea was evaluated. Severe heat damage was observed on the fruits heat-treated after CTS coating (CTS+HT), appeared as external decay and internal brown after treatment. However, no damage on fruits heated before CTS coating (HT+CTS) during the whole storage. Besides the completely control of blue mold and gray mold on artificially inoculated fruits during storage, the HT+CTS treated fruit showed the lowest respiration rate, ethylene evolution, malondialdehyde and membrane leakage, and the highest firmness and consumer acceptance among the treatments. At the same time, this combined treatment could inhibit the lost of green color, titratable acidity and weight loss compared with HT alone.10 page(s