Edible Films and Coatings

This books opens with a review of the latest advances in edible film composition, including the use of macromolecules in the structural matrix, bioactive compounds, diffusion, and application in food systems. Continuing, the authors investigate edible coatings based on natural polymers (soy protein-SPI and potato starch) considering the effect of process variables such as drying temperature and time. Kinetic modeling was used to study the drying behavior of potatoes after applying the coating. The Fick equation was considered to calculate the mass diffusivity. The following chapter describes cases of application of edible coatings, based on hydrocolloids, in different types of food and evaluates their impact in the shelf life of those food products. A study is presented wherein edible films were developed from cassava starch, hydroxypropyl methylcellulose, glycerol as plasticizer, and the antimicrobial potassium sorbate. Oregano powder was added in order to obtain composite films. A mechanical test was performed until rupture and the parameters elastic modulus, stress, and strain at rupture were obtained. The potential application of WPC-based edible coatings with Origanum virens essential oils, as antimicrobial and antioxidant agent, is presented as a case study in two traditional Portuguese sausages. WPC-based edible films were prepared by heat-induced gelation using the conventional solvent casting method. The effect of glycerol as plasticizer and the addition of plant extracts or essential oils to the films is addressed to assess their effect on the film properties. Afterwards, the authors describe the hydrocolloids and essential oils that can be used in the production of active packages, as well as their benefits. The use of essential oils in biofilms has inhibited the growth of several microorganisms, such as Escherichia coli, Staphylococcus aureus, Salmonella enteritidis, Listeria monocytogenes, and Lactobacillus plantarum. In the final presented study, vegetable foods were prepared from blanched Cucurbita moschata Duchesne ex Poiret and enriched with probiotics, particularly Lactobacillus casei or enriched with probiotics and fortified with iron (Fe). In order to extend the shelf life of the product, it was tested with the application of edible coatings combined, and not combined, with a drying process.