Keywords: anti–browning solutions, chitosan coating, edible coatings, apple quality, fresh cut apples, ascorbic acid, citric acid, firmness, colour, CO2, carbon dioxide, ethylene, microorganisms
Effects of antibrowning solution and chitosan–based edible coating on the quality of fresh–cut apple
Fresh–cut apples were treated with an antibrowning solution and with a chitosan–based edible coating associated to antibrowning agents and the effects on the deterioration at low temperature were studied. The combined effect of ascorbic acid (AA), citric acid (CA) and chitosan was also evaluated. Control, coated and uncoated apples were packed in polyethylene terephthalate trays and the changes in headspace atmosphere, colour, firmness and microbial growth measured along ten days of storage at 5°C. The samples coated with 1% AA + 2% CA + chitosan maintained a good colouration until day 6, similar to those treated with 1% AA + 2% CA without chitosan. Afterwards, the fruits became darker and similar to the control. A slight reduction in the rates of CO2 production was observed in all samples. Ethylene increased continuously during storage although gas production was extremely low. Texture did not change for all treatments; showing values around 9.0 to 10.0 N. Growth of Salmonella, and total and fecal coliforms were not detected. The chitosan coating treatment was the most effective in inhibiting growth of moulds and yeasts, with count of 1.7 CFU g−1. Chitosan coating could be an alternative for preserving quality of fresh–cut 'Gala' apples. Results from this study suggest that.