Elaboração e aplicação de filme a base de amido na conservação de queijo tipo mussarela

Abstract

The environmental impact caused by packaging has increased interest in the use of biodegradable materials to replace conventional plastics. The use of starch suggests many applications because it is a renewable and biodegradable. Cassava is a root that has a low production cost and is easy to grow. The aim of this work was to produce biodegradable films by extrusion from blends of cassava starch, glycerol, poly (butylene adipate co-terephthalate) (PBAT), butylated hydroxytoluene (BHT) and/or oregano essential oil and apply it as packing for the conservation of mozzarella type cheese. Analyses were performed on films: tensile and perforation tests, water vapor permeability (WVP), opacity and sorption isotherm. The mozzarella type cheese slices were packed in three formulations (F1, F2, and F3) and stored in a chamber at 8±1⁰C and 55% relative humidity (RH). The physicochemical characteristics (moisture, protein, ash) and microbiology of the food product were analyzed during storage (10 days). The essential oil incorporated in the film contributed to the reduction of tensile strength and increased elongation, films of starch and PBAT blends showed an elongation of 56.7%, while those added with essential oil showed 74.4% of elongation. The additive BHT contributed to reduce the the WVP. The addition of 1% of additives in the films showed no effect on solubility. The films showed an opacity average of 55%, being considered opaque which contribute as a light barrier. During storage there were moisture losses due to high WVP of films. Escherichia coli and Salmonella spp. were absent in food product, but for mesophylic microorganisms, yeasts and molds it was observed a growth. The oregano essential oil could have been volatilized during processing, which explains why it didn’t work as antimicrobial agent. The biodegradable films can be an alternative for packaging of mozzarella type cheese, however, further studies must be performed to ensure and enhance the activity of antimicrobial essential oils to allow its use in packaging, so they can be considered active packaging. Also, further studies are necessary to improve the barrier properties of bioplastics.