Microbiological Evaluation of Edible Coated Fresh-Cut Cantaloupe

Abstract

This work aimed to investigate the effectiveness of the incorporation of chitosan as an antimicrobial additive in the edible methyl cellulose coating on the microbiological quality of fresh-cut cantaloupe. Cantaloupe slices were coated with edible coating solutions after washing in chlorinated
water. The coating solutions were mixtures of 3% methyl cellulose and 2% glycerol that contained 0, 1, 1.5 and 2% of chitosan respectively. The slices were drained, packed on polystyrene trays and wrapped with polyvinylchloride film. The samples were stored at 10°C for 15 days. During storage, samples including a control (cantaloupe slices without coating) were collected every five days for microbiological analysis of mesophillic aerobes, psychrotrophs, lactic acid bacteria, yeast and mold, Staphylococcus aureus, total coliforms, Escherichia coli and Salmonella spp. Applications of 1.5 and 2% chitosan in the methyl cellulose coating of fresh-cut cantaloupe produced a better microbiological quality in the products. Chitosan reduced the growth of mesophillic aerobe (3.3 log cfu g^-1), psychrotrophs (3.9 log cfu g^-1), lactic acid bacteria (3.1 log cfu g^-1), yeasts and molds (1.1 log cfu  g^-1) and total coliform (3.8 log cfu g^-1). Moreover, S. aureus, Salmonella sp. and E. coli were as low as <10 cfu g^-1, <10 cfu g^-1 and 0 MPN g^-1, respectively.