Physico-chemical and antimicrobial properties of casein-chitosan edible films as food quality and food safety

Edible films can be useful in extending product shelf life and the surrounding environment to enhance the quality of food products protecting from physical, chemical, biological deterioration. Casein and chitosan are natural materials for producing edible films. These films are also able to incorporate as barriers to water vapor, oxygen and carbon dioxide and as carrier substances to inhibit pathogenic and spoilage microorganisms. Observations were conducted to the formulations of the casein and chitosan solution ratio 1: 1; 1:2; 1:3 and 1:4 (ml:ml) in order to determine one that yields the best solution. The objectives of this study was to characterize physicochemical (water vapor permeability, water activity, and film solubility) and antimicrobial properties of casein-chitosan (Staphylococcus aureus, Lactobacillus bulgaricus, Escherichia coli, and Salmonella sp.). The effect of the casein-chitosan on edible films was monitored. The best solution on casein:chitosan ratio = 1:4 (ml:ml). The greatest water vapor permeability with 0.1140 g.mm/m(2).h.kPa, film solubility with 32.809% and water activity with 0.709. Antimicrobial activity of edible films casein-chitosan against Staphylococcus aureus, E.coli, Salmonella sp. and Lactobacillus bulgaricus was ratio solution dependent.