Novel functional polysaccharides as edible coatings for cheese

One of the problems occurring during cheese ripening and later on, throughout the distribution chain, is the occurrence of molds and the loss of water. Usually, this problem is solved by the use of synthetic coatings where an antimicrobial agent is introduced. Polysaccharide coatings have an oilfree appearance, a low caloric content and can be used to increase the shelf life of foods. The objective of this work was to study the ability of polysaccharides from different and novel sources to be used as coatings for cheese. The tested materials were: chitosan, galactomannan of Gleditsia triacanthos and agar of Glacilariae birdiae. Different formulations were tested with the addition of plasticizer (glycerol and sorbitol), oil and Tween 80. The surface properties of the cheese and the wetting capacity of the coatings on the cheese (in terns of the spreading coefficient) were determined. Based on the values of the spreading coefficient of the polysaccharides solutions the three best solutions for each polysaccharide were chosen. For the chosen solutions, the water, oxygen and carbon dioxide permeability of the films were determined, as well as solubility, opacity and chromaticity. The solutions of G. triacanthos present the best properties to coat the cheese. The O2 consumption and CO2 production rate, as well as the weight loss, of the cheese with and without coating were measured. The gas exchange rates of the cheese were found to decrease in the coated cheese. Also the weight loss from the cheese was lower in the coated cheese.Fundação para a Ciência e Tecnologia (FCT) Queijo Saloio S.A.Valnatura project (EU