Preparation and Characterization of Biocomposite Films with Enhanced Oxygen Barrier and Antioxidant Properties Based on Polylactide and Extracts from Coffee Silverskin

In the food packaging industry, significant efforts have been dedicated to addressing the pressing market demand for environmentally friendly and sustainable products. Biocomposite films based on compostable and biobased polymers represent a sustainable alternative to conventional packaging materials, offering biodegradability and enhanced functional properties. Additionally, there is growing interest in utilizing waste materials from agriculture and the food industry. This study focuses on the development of multifunctional eco-sustainable biocomposite films by combining poly(lactic acid) (PLA) as a biopolymeric matrix and extracts derived from coffee silverskin (CS), a significant agro-industrial waste byproduct of the coffee roasting process. Extracts of coffee silverskin were obtained via extraction with several solvents. Several properties of the prepared biocomposites were measured using techniques such as scanning electron microscopy (SEM), infrared spectroscopy (FTIR, ATR), differential scanning calorimetry (DSC), and oxygen and water vapor permeability, together with mechanical and physico-chemical characterization and measurements of water content, film solubility, and degree of swelling. The results demonstrate that optimized formulations of PLA/CS biocomposite films exhibit enhanced oxygen barrier properties, reduced permeability, and significant antioxidant activity. These findings underscore the potential for agro-waste valorization in creating eco-friendly food packaging solutions.