Eficácia da atividade antioxidante e caracterização de embalagens ativas biodegradáveis formuladas com amido de mandioca e derivados de cacau e café

Abstract

At the search for antioxidants naturally occurring in plants as alternative to synthetic antioxidants, the main objectives of this study were evaluated the use of coffee and cocoa phenolic compounds as antioxidant additive for bio-based cassava starch-plasticizers packaging, also characterize the thermo and mechanical properties of the bio-based films. Shelf life over accelerated oxidation (63%RH/30°C) of Palm oil (PO) packed with the bio-based materials with phenolic compounds additives (coffee powder and cocoa powder) were monitored for 45 days. PO packed with cassava starch films (without antioxidants) (C1), LDPE (C2) and without packaging (C3), served as controls. Results have indicated that after 45 days of storage products packed with biobased films containing the highest phenolic compounds concentration presented the lowest oxidation. To evaluate the thermo and mechanical properties a bio-based film without additives (C) served as control. Results have indicated that bio-based films containing the additives affected the materials IR spectrums, water vapor permeability, thermal and mechanical properties (p<0,05). The water vapor permeability had a decrease when the additives were increased at high concentration (FB – 1.0% of cocoa powder and 0.23% of coffee extract, FC – 1.7% of cocoa powder and 0.39% os coffee extract), the elongation and the tensile strength of the films demonstrated its values at - 17.86 until 312% and 42.33 until 54.67%, comparing with control (C), depending its concentration. The glass transition temperature (Tgs) were significantly (p<0.05) altered, with maximum additives concentration there was an increase in the Tgs number; however at minimum additives concentrations (FA – 0.30% of cocoa powder and 0.07% of coffee extract) was a decrease in Tgs number. Thus, the combination of coffee and cocoa phenolic compounds in the biobased cassava starch-plasticizers packaging conferred the highest antioxidative properties. Also the physical properties of edible films can be affected by the cocoa and coffee additives, altering biofilm performance.