Advancements in microbial production of polyhydroxyalkanoates (PHA) from wastes for sustainable active food packaging: An eclectic review

Search for alternatives to synthetic plastics led to the development of eco-friendly degradable polymers of natural origin termed ‘bioplastic’ which is a sustainable option to reduce the reliance on fossil fuel resources and address the needs of pressing environmental problems. Food packaging has become an important aspect of supply chain management that not only governs the food from spoilage but also contributes to a sensible biocompatible material, safe for human consumption as there is a recent concern on microplastic leaching. Polyhydroxyalkanoates (PHAs), derived from microorganisms, are extensively used as a polymeric base for packaging applications in food industries as they offer advantages such as biodegradability, non-toxicity, hydrophobicity, thermoplasticity, and superior barrier properties, thereby making them a promising alternative to conventional synthetic plastics. However, challenges related to material properties, performance, and cost of the product must be addressed for PHA to make it an economical and feasible packaging material. Recent developments in PHA formulations in terms of technology, additives, and production factors have led to improvement in the polymer properties and beaconed the advent of active packaging. PHA-based packaging systems can redefine food industry packaging, turning it from a passive physical entity into an active solution that sustainably ensures food quality and safety. This review examines the sustainable microbial production of PHA from waste resources, recent advancements in PHA formulations, and their impact on material properties. It highlights emerging trends in active food packaging with PHA, such as controlled-release, antimicrobial and antioxidant properties, advanced barrier properties and spoilage indicators.