Polyhydroxyalkanoates (PHAs) are promising biodegradable polymers known for their biodegradability and eco-friendly properties. Recent studies indicate that PHAs can reduce the environmental impact by up to 50% compared to petroleum-based plastics. This comprehensive review evaluates the application of PHAs in sustainable food packaging, covering over 100 studies published between 2018 and 2023. The review highlights advancements in PHA production, with a focus on submerged and solid-state fermentation methods, achieving up to a 60% improvement in production efficiency through optimized culture selection. Sustainable extraction and purification methods have been identified, reducing energy consumption by 30%. Blending PHAs with other biodegradable polymers like polylactic acid, starch, and cellulose enhances material performance, with up to a 40% improvement in mechanical properties. The incorporation of antimicrobial agents and essential oils has been shown to extend the shelf life by 25% while maintaining food safety standards. This review underscores the potential of active PHA-based packaging in improving the barrier properties by 35% when combined with coatings, positioning PHA as a key material for the future of environmentally responsible and safe food packaging.

The environmental impact of plastic waste is a growing global challenge, primarily due to non-biodegradable plastics from fossil resources that accumulate in ecosystems. Biodegradable polymers like polyhydroxyalkanoates (PHAs) offer a sustainable alternative. PHAs are microbial biopolymers produced by microorganisms using renewable substrates, including agro-industrial byproducts, making them eco-friendly and cost-effective. This study focused on the isolation and characterization of PHA-producing microorganisms from agro-industrial waste, including chickpeas, chickpeas with bean residues, and starch. Screening via Sudan Black staining identified PHA-accumulating strains such as Brevibacillus sp., Micrococcus spp., and Candida krusei, among others. To assess the potential for PHA biosynthesis, solid-state fermentation (SSF) was conducted using agro-industrial waste as substrates, along with a mixed culture of the isolated microorganisms. The highest observed yield was a PHA accumulation of 13.81%, achieved with chickpeas containing bean residues. Structural and thermal characterization of the PHAs was performed using Fourier-transform infrared spectroscopy with attenuated total reflectance (FTIR-ATR), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA). FTIR-ATR spectra indicated polyhydroxybutyrate (PHB), suggesting it as the synthesized PHA type. This study highlights the potential of agro-industrial waste for sustainable PHA production and eco-friendly bioplastics.