CHITOSAN SOLUTIONS WITH DIFFERENT DEGREES OF ACETYLATION AS COATING ON CUT APPLE

Abstract

In this study we analyzed the protective properties of different types of chitosan on minimally processed apples, concerning water loss, surface color changes and antifungal activity. Seven different chitosanbased formulations with variable molecular weight and degrees of acetylation were prepared and used to coat sliced apples which were stored in a greenhouse at 28o C and RH 80%. The coatings, with concentration of 2.0g/L, independent of chitosan type, had no significant effect in protecting the samples against loss of mass by water vapor permeation. Along the storage time, all samples resulted in similar dehydration. Gradual browning was observed in cut fruit, whereas chitosan did not maintain natural color of the cut surfaces. Concerning antifungal activity, chitosans with low molecular weight and low degree of acetylation was the best formulation, reducing in around 50% the fungal incidence after 10 days of storage.

Keywords

• Edible coating
• fungicide
• minimally processed fruit
• enzymatic browning