Revestimentos comestíveis à base de amido de mandioca com óleos de polpa e amêndoa de pequi

Abstract

Biodegradable films based on cassava starch represent excellent alternatives for edible and sustainable coatings to replace traditional petrochemical polymers. Vegetable oil emulsions can increase the flexibility of polymers, improving their mechanical properties, being safe and environmentally friendly, which has increased interest in their application in the food industry. In this context, the aim of this study was to add emulsions of pequi pulp and kernel oil to starch and pectin matrices to produce films, as well as to evaluate the effect of the emulsions on the properties of the film for food coating. The emulsions were observed under an optical microscope and scanning electron microscopy, showing the stability and dispersion of the oil droplets after 24 hours. The results of the analyses of the mechanical properties (puncture, Young's modulus, traction and elongation) showed improvements in the elasticity and flexibility of the material. The moisture barrier properties (contact angle, wettability and water vapour permeability) of the films allow them to be characterised as hygroscopic materials. The treatments proved to be compatible with the composites present in the mixtures, as represented by the XRD and FTIR analyses. Thus, the application of pequi pulp and kernel oil to cassava starch films showed the importance of emulsion stability in polymeric matrices, suggesting the use of higher concentrations of oils for food coating applications.