Aplicação de matrizes biopoliméricas para revestimento de grãos de cafés especiais

Abstract

The valorization of specialty coffees has sparked the interest of producers and researchers in seeking sustainable alternatives that ensure the preservation of grain quality after harvest. Among the promising strategies, the use of edible and biodegradable coatings stands out, acting as physical and biochemical barriers, protecting the grains against adverse environmental factors. In this context, the present work aims to develop, characterize, and apply coatings based on Aloe vera, pectin, and starch, incorporating them as protective coatings for specialty coffee beans. The chosen biopolymers exhibit high availability, renewability, and excellent compatibility with food systems, while Aloe vera is known for its antioxidant and antimicrobial properties that can contribute to maintaining the quality of the grains. Formulations were prepared by varying the proportions of pectin and starch, with the addition of Aloe vera extract, aiming to optimize the physicochemical properties of the films, such as viscosity, transparency, thickness, water solubility, along with microscopic and adhesion analyses on the beans. The coffee beans were coated by immersion and stored under controlled conditions for determined periods, being monitored for water activity, coloration, volatile compound profiles, and preservation of sensory attributes. The results indicate that coatings based on starch showed superior performance in grain coating, promoting lower oxidation, and maintenance of desirable visual characteristics. The proposed approach proves promising as a clean and effective technology to increase the shelf life and quality of specialty coffees, potentially being incorporated as an innovative step in post-harvest processing. This study also reinforces the importance of applying functional biopolymers in the agroindustry, contributing to product value addition, loss reduction, and promoting sustainability in the coffee production chain.