Influência do peso molecular do polímero na morfologia, interação e liberação de flavonoides em filmes de poli (álcool vinílico)

Abstract

Active packaging works in favor of product quality, reducing the oxidation reactions that occur when food comes into contact with air. In an attempt to produce a film with these characteristics, the incorporation of flavonoid into the PVA was proposed. Polyvinyl alcohol (PVA), widely used in the packaging industry, is a synthetic polymer, which in this work received quercetin, a flavonoid, with antioxidant power. The films were prepared by the casting method, varying the molecular weights of the PVA and the following concentrations of quercetin: 0, 50 and 100 mg. The films were evaluated for homogeneity and dispersion of material by FT-IR, X-ray Diffraction and Atomic Force Microscopy. For the Determination of Antioxidant Potential (ABTS, DPPH and CF) extracts were prepared following the European Regulation (2011) to simulate different types of food. The water absorption rate and the quercetin release profile of the films were investigated. In the FT-IR analyzes the main functional groups of the materials were identified, in the X-ray diffractograms the characteristic peaks of the materials. The PVA films with quercetin presented antioxidant power, mainly the low molecular weight films submitted to the greasy simulant (95% Ethanol: 5% Water). The dispersion of compounds was affected by the preparation methods and the water absorption rate of the PVA decreased with the insertion of quercetin into the PVA. The formulation with high molecular weight PVA with 100 mg of quercetin presented the best values in the evaluated items in this work, for the use of active packaging with antioxidant action.