A review of pullulan nanopolymer derived from agro-food waste and its applications

Pullulan is a microbial exopolysaccharide hydrogel biopolymer that is biodegradable, renewable, and environmentally friendly. However, to meet the demands of the utilization, it is still necessary to enhance the yield and molecular characteristics of pullulan formed by different strains. Available in powder form, pullulan enhances the benefits of this natural material when combined with nanoparticles (NPs) and synthesized into pullulan NPs. NPs are gaining attention as a cutting-edge technology in the fields of pharmaceuticals, medicine, food, agriculture processing, and packaging. Pullulan biopolymers provide an environmentally friendly solution that effectively addresses the world's waste disposal issue by removing untreated waste from the agro-food industries and using this waste as a potential substrate for pullulan biosynthesis. Nowadays, pullulan in the form of NPs, nanocomposites, and nanoformulation has become increasingly popular because of their specific application needs with enhanced molecular properties like strength, durability, electrical conductivity, and catalytic activity. This approach offers a valuable product called pullulan-based nanopolymer, which holds promise in various industries. Pullulan with the highest yield capacity to date has the potential to significantly decrease production costs and increase applicability range. This review provides detailed insights into the latest methods for extracting pullulan biopolymers from agricultural and food waste materials in the form of polysaccharides. Moreover, the article covers the synthesis of various types of pullulan-based nanoparticles, nanocomposites, and nanoformulations. Furthermore, it delves into the diverse applications of these pullulan nanopolymers across agriculture, food and medical sectors.

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