Microbial-Mediated Biopolymers (Exopolysaccharide) in Food Packaging: A Current Time Approach in Food Safety

Secure food delivery is a leading issue in the current time, where more than 50% of food waste is due to poor packaging. Microbial biopolymers (exopolysaccharides) present a strong option as a packaging material owing to their biocompatibility, nontoxicity, and potential application in foodstuff packaging. Exopolysaccharides (EPSs) are important biopolymers produced by microorganisms with unique characteristics that make them useful in food packaging. The molecular weight of EPS is usually between 10 and 10,000 kDa. EPS possesses antioxidant, prebiotic, and antibacterial activities, and eco-friendly and nontoxic biopolymers. EPSs produced by Lactobacillus, Lactococcus, Streptococcus, Bifidobacterium, Bacillus, and Weissella are characterized by their considerable film-forming and rheological characteristics, such as viscosity, elasticity, besides gelation, and consequently can be used to develop edible packaging, as structural additives, and as functional packaging in the dairy, meat, bakery, and beverage industries. During gel formation of gellan gum and xanthan, the storage modulus (G’) exceeds the loss modulus (G”) and improves mechanical strength. In the biosynthesis pathway, the pgmU gene converts glucose-6P into UDP-glucose, and the galU gene’s phosphorylase converts glucose-1P into UDP-glucose. Overexpressing the galU and pgmU genes in the pathway has been utilized in metabolic engineering to boost UDP-glucose synthesis. Integrated application of Ag, TiO2, ZnO, chitosan nanoparticle, and EPS has improved antibacterial (like Escherichia coliand Staphylococcus aureus) and rheological properties. Furthermore, EPS is decomposable and may be considered a renewable source of energy, although full commercialization of EPS in food packaging is still a challenge owing to regulations in different countries.