Recobrimento de goiabas com filmes proteicos e de quitosana

Abstract

The objective of this study was to evaluate the effects of chitosan and protein coatings on the conservation of 'Kumagai' guavas. Chitosan coatings with and without glycerol (1:1) at 2; 4 and 6% concentrations, whey protein concentrate (WPC) coatings with glycerol (1:1) at 6 and 8% concentrations and gluten with glycerol coatings (1:1) at 10 and 12% concentrations were used. Coatings were applied by dipping guavas in the solutions for 10 seconds and dried at room temperature in a forced air circulation chamber. Subsequently, fruit were stored at room temperature (22±2 oC and 70±5%RH) for 8 days. Chitosan coating at 6% without glycerol prevented fruit ripening and fruit gave off an alcoholic smell on the 8th day. Apart from the chitosan coating at 6%, the other treatments caused similar responses when compared to control group within the fruit conservation period considered.