Effect of Natamycin on physical properties of starch edible films and their effect on Saccharomyces Cerevisiae activity

Abstract

The effectiveness of using a tapioca starch–glycerol matrix containing natamycin to control Saccharomyces cerevisiae activity in a model system was studied and the effect of the formulation on physico-chemical properties was also evaluated. The presence of natamycin tended to depress firmness at break and Young modulus and to increase strain at break. Colour was also affected by antimycotic presence. The importance of these changes will be determined by the characteristics of the product to which the antimicrobial film will be applied. The films developed were capable of acting as a hurdle against S. cerevisiae in food systems during storage: they acted as an effective reservoir of the antimycotic which was also available to prevent an external contamination. The films containing 1.85 mgnatamycin/dm2 of natamycin developed a fungistatic effect till 72 h of storage, while those with a 3.70-mg natamycin/dm2 concentration developed a fungicidal action allowing the selection of the proper formulation according to the antimicrobial goal pursuit. As natamycin addition affects mechanical properties and colour of the films, it is advisable to use the lower natamycin concentration that allows the attainment of the goal pursued for film application.