DEVELOPMENT OF BIOPOLYMERIC FILMS BASED ON PECTIN AND PROTEIN OBTAINED FROM AGRI-FOOD WASTE

One of the biggest challenges today is climate change, caused by the emission of greenhouse gases such as carbon dioxide, methane and nitrous oxide. In its 2022 Emissions Gap Report, the United Nations proposes several routes of action, among which the promotion of circular material flows stands out. One way to work on this route is to use agri-food waste as raw material, given that today around a third of all food produced for human consumption in the world is wasted.
Therefore, the aim is to reuse waste to produce biopolymeric films whose objective is to replace petroleum-derived polymers in different applications, such as edible food packaging and coatings.
Therefore, the present work aimed to produce biopolymeric films using the casting technique using citrus pectin at concentrations of 0.8, 1.6, and 3.2% (w/v) and isolated sunflower seed protein at concentration 2% (w/v), coming from sunflower pressing cake.
The films were characterized regarding their mechanical, thermal, morphological properties and the chemical groups present by FTIR. It was observed that the addition of pectin to the protein film led to an increase of up to 193% in the tensile strength limit, a reduction of up to 82% in elongation and an improvement in thermal stability, increasing the temperature of greatest percentage loss of mass from 129 °C to up to 232 °C. The films had a dense appearance without cracks or apparent pores.
In parallel, pectin was extracted from the pequi peel, obtaining a yield of 11.99 ± 2.05% and a degree of esterification of 81.63 ± 11.49%. The pectin obtained showed film-forming capacity and, therefore, it is expected to be applied in film formulations with protein isolated from sunflower seeds in order to reuse agri-food waste.