Filmes biopoliméricos de pectina e proteína isolada de girassol: desenvolvimento, caracterização e aplicação sustentável do mesocarpo de pequi.

Abstract

The packaging used for food products is mostly made of synthetic polymeric materials, especially plastics, which contribute significantly to greenhouse gas emissions and the contamination of terrestrial and aquatic environments. Given the growing demand for environmentally responsible solutions, biopolymers from renewable sources, such as carbohydrates and proteins extracted from agro-industrial wastes, are emerging as promising alternatives for the development of sustainable packaging materials. In this context, this study aimed to develop and characterize biopolymeric films formulated from isolated sunflower protein combined with commercial citrus pectin in different proportions. Additionally, the replacement of commercial pectin with pectin extracted from the mesocarp of pequi (Caryocar brasiliense Camb.) was investigated as a strategy to further enhance the sustainability of the produced material. Among the main results obtained, the formation of films with favorable oxygen and water vapor barrier properties was highlighted, particularly the film containing 80% protein and 20% pectin, which exhibited the lowest permeability values. This blend was selected for comparative evaluation between commercial citrus pectin and pectin extracted from pequi mesocarp. The extracted pectin showed a degree of esterification above 50%, comparable to that of commercial pectin. The substitution did not result in differences regarding barrier properties. However, significant differences were observed in the mechanical properties. Most of the blends, as well as the pure protein films, were biodegradable within 10 days of soil exposure, demonstrating the sustainability of the packaging. It was concluded that it is feasible to produce films based on commercial pectin or pectin extracted from pequi mesocarp combined with protein isolated from sunflower seeds, representing a sustainable alternative to conventional plastic packaging.