Desenvolvimento e caracterização de embalagens biodegradáveis de colágeno e resíduos agroindustriais (mesocarpo de coco verde e bagaço de azeitona).

Abstract

Synthetic polymers derived from petroleum are an environmental concern because they are neither renewable nor biodegradable. Biodegradable films made from natural polymers, such as polysaccharides, lipids, and proteins, have emerged as promising and sustainable alternatives for food packaging. Waste from the production of olive oil and green coconuts are potential raw materials for biodegradable polymers. Thus, the objective of this study was to develop and characterize biodegradable packaging produced from the by-products of olive oil and green coconut processing. First, green coconut mesocarp (FMC) flour was produced and characterized, presenting a promising physicochemical composition, with low moisture content (11.77%), lignocellulosic composition (9.71%, 41.69%, 0.02%, and 38.07% for hemicellulose, cellulose, soluble lignin, and insoluble lignin, respectively), phenolic compounds (9.49 EAG.g⁻¹), and antioxidant activity (146.87 μM Trolox.g⁻¹, 185.34 μM FeSO₄.g⁻¹, and 728.4 IC₅₀ expressed in mg of fruit L⁻¹ of DPPH). The flour also demonstrated hydrophobic capacity, with swelling power ranging from 10.80 to 11.50 and water solubility from 16.36 to 19.06, making it a viable alternative for the food and packaging industries. FMC exhibited remarkable thermal stability, maintaining its physical and chemical properties even in the face of temperature variations (29 to 600°C). This characteristic is particularly important for applications that require heating, such as the production of pasta and plastic packaging, contributing to the reduction of environmental impacts from coconut waste in the food chain. Next, six packaging formulations were developed, varying the concentrations of green coconut mesocarp flour and including the by-product of olive oil extraction (SBTA) using the casting method. The addition of mesocarp flour provided rigidity to the packaging. The inclusion of agri-food residues resulted in rapid degradation, beginning from the third day, demonstrating the biodegradability of the packaging. Based on the results, it is suggested that the inclusion of green coconut mesocarp flour in packaging is a promising option for biodegradable materials. This could significantly contribute to the reduction of environmental impacts associated with the disposal of agri-food waste and synthetic packaging. After characterizing the packages, one was selected based on its physical and mechanical properties and applied to gluten-free cakes made with millet flour. These cakes were evaluated over six days of storage at different temperatures (5°C and 25°C). The biodegradable packaging preserved the yellow tone of the millet cakes and reduced moisture loss, with significant differences observed between the evaluation days, leading to a marked reduction in water activity. Although the biodegradable packaging did not maintain the moisture content, the incorporation of SBTA and FMC exhibited antimicrobial properties, potentially increasing the product’s shelf life. These results indicate a promising application of packaging to impart antifungal properties to products, though further testing is needed to improve its effectiveness.