Optimizing polylactic acid: synthesis, properties, and regulatory strategies for food packaging applications

Polylactic acid, a biodegradable polymer derived from renewable resources, is increasingly used in food packaging due to its transparency, renewability, and food safety. However, its mechanical properties, heat resistance, and barrier performance present significant challenges that limit its application. Currently, there is a lack of comprehensive literature addressing methods to optimize polylactic acid’s performance for various food packaging application. Hence, this review provides an overview of polylactic acid production processes, including the synthesis of lactic acid and lactide, as well as methods such as polycondensation and ring-opening polymerization. We critically examine the advantages and limitations of polylactic acid in various food packaging contexts, focusing on strategies to enhance its mechanical properties, barrier performance against oxygen and water vapor, surface hydrophobicity, thermal stability, and resistance to ultraviolet light. Furthermore, we summarize recent advancements in polylactic acid applications for food packaging, highlighting innovations in antioxidant, antimicrobial, and freshness indicator packaging. These developments underscore the significant potential of polylactic acid in the food packaging sector and offer valuable insights for future research directions.