Aproveitamento sustentável dos resíduos de pescado para obtenção de revestimentos/filmes, aplicação na conservação pós-colheita de goiabas (psidium guajava l.), estudo da estabilidade e funcionalidade desses filmes

Abstract

In the present study, a coating based on myofibrillar proteins (PML), corn starch (AM), and gum arabic (GA) were used to verify the rheological behavior and its influence on the extension of the shelf life of 'cortibel' guavas. Subsequently, the effect of the mixture PML/glycerol 10% (Gly) – coating A, and PML/Gly/GA at concentrations of 30 and 40% (w/w) of Gly, called coatings B and C, respectively, was evaluated. in the quality of 'paloma' guava. For technological characterization, the functional properties and moisture sorption behavior of PML and Gly-based films were evaluated at concentrations of 5, 10, 15, 30, and 40%. After selecting the best behavior of the PML-based films, the interactions between PML and GA were analyzed in the different proportions (10.0:0.0; 9.5:0.5; 9.0:1.0; 8 .5:1.5; 8.0:2.0 and 7.5:2.5), called E1, E2, E3, E4, E5 and E6, respectively. Among the analyzed coatings (PM; AM; GA), AM had the highest viscosity (p ≤ 0.05), followed by PML and GA, characterizing very viscous, viscous, and very diluted dispersions, respectively. The loss of mass and firmness of fruits coated with PML and AM showed lower (p ≤ 0.05) percentages on the evaluated days. Coating C (1%PML/40%Gly/1%GA) delayed the ripening rate (p ≤ 0.05) of the coated fruits. In the sorption process, films obtained curves of type II (5% glycerol) and III (10 to 40% glycerol), in which high concentrations of Gly resulted in an increase in their water content and a decrease in hysteresis until their disappearance. The E4 blend film (8.5%PML/1.5%GA/40%Gly) showed greater compatibility and integration into the structure, with low permeability to water vapor, a property required for food packaging. It is concluded that the application of coatings had a positive contribution by delaying the maturation process and increasing the commercial life of 'cortibel' and 'paloma' guavas. Fish PML films with low glycerol addition can be industrially processed and used to protect food, as they showed low hygroscopicity. The incorporation of GA in the mixed films (PML/Gli/GA) had an important effect on the technological properties, due to the interaction with myofibrillar proteins and glycerol.