Lipid-Enriched Biopolymer Films for Active Packaging: A Review of Structure, Properties, and Preservation Performance

Amid growing environmental concerns regarding the use of non-biodegradable plastic packaging and its potential emerging contaminants, such as microplastics, currently among the most pressing global challenges, researchers in the food sector are increasingly pursuing sustainable alternatives. In this context, various organic sources have been explored for the development of innovative biocompatible films. These films exhibit properties such as low water vapor permeability, transparency, and biodegradability, and have recently gained active functionalities. These enable the extension of the shelf life of packaged foods by controlling microbial activity and oxidative degradation. Lipid-based compounds derived from animal and plant sources-including phospholipids, essential oils, free fatty acids, and saturated and polyunsaturated fatty acids-have proven highly effective when incorporated into films, leading to significant physicochemical, mechanical, and microbiological improvements in both the films and the packaged products. Owing to their high hydrophobic capacity, these lipids markedly reduce water vapor permeability, which is crucial for extending the shelf life of high-moisture foods. Studies have shown that the incorporation of lipid compounds can increase film tensile strength by up to 37% and enhance antioxidant activity by over 75%. Moreover, many of these compounds exhibit antibacterial and antimicrobial activities, becoming active on the surface of food in contact. However, many bioactive compounds have poor dispersion in aqueous solutions, limiting their effectiveness in the final product. When encapsulated with the aid of a lipid fraction, the bioavailability of these compounds is improved, and their release can be effectively controlled. This review aims to consolidate recent research on the production of biopolymer films incorporating various types of lipid compounds, highlighting their enhancements and potential applications in active food packaging systems.