Driven by the "dual carbon" strategy and the concept of green and sustainable development, the packaging materials industry is undergoing profound changes. Traditional plastic materials have been criticized for their non degradability and serious environmental pollution, while green and environmentally friendly new materials are gradually entering the industry's vision. In recent years, Poly - γ - glutamic acid (PGA), as a natural polymer with excellent biodegradability and environmentally friendly properties, has made continuous breakthroughs in technological research and development. Its application prospects in the field of green packaging materials have attracted much attention.

The unique advantages of polyglutamic acid

Polyglutamic acid is a water-soluble natural polymer synthesized by microbial fermentation of glutamic acid molecules, widely present in the metabolites of certain natto bacteria. Compared with traditional petrochemical based plastics, PGA has the following advantages:

·Strong biodegradability: PGA can quickly decompose into amino acids in natural environments without causing "white pollution".

·High biological safety: Its degradation products are harmless to humans and the environment, meeting the requirements of green consumption and environmental protection policies.

·Film formation and processability: PGA molecules contain abundant carboxyl and amino groups in their structure, making them highly promising for film formation, cross-linking, and composite modification.

·Functional adjustability: Through molecular weight control and chemical modification, PGA can endow packaging materials with different mechanical and barrier properties, meeting diverse application needs.

Therefore, PGA is considered an important candidate material to replace some petrochemical plastics and promote the upgrading of the green packaging industry.

Technological breakthroughs drive industrialization

For a long time, the industrial application of PGA has been constrained by low fermentation efficiency, high cost, and insufficient modification technology. However, in recent years, significant breakthroughs have been made in scientific research and industry in the following areas:

·Efficient strain selection: Through genetic engineering and metabolic regulation techniques, researchers have cultivated high-yield and stable fermentation strains, significantly increasing the yield of PGA.

·Green fermentation process: Using agricultural by-products such as molasses and starch hydrolysate as raw materials not only reduces production costs but also achieves recycling.

·New technology for material modification: Through copolymerization, composite filling, and cross-linking reactions, PGA film materials have improved in strength, barrier properties, and water resistance, making them more suitable for packaging needs.

These technological advancements have made the application of PGA in the field of packaging materials no longer limited to the laboratory stage, but gradually move towards commercialization.

The application prospects of green packaging

With the tightening of policy regulation and the increasing awareness of environmental protection among consumers, the demand for green packaging market is growing rapidly. The application of PGA in this field has broad prospects:

·Food packaging: PGA film has good breathability and barrier properties, which can delay food oxidation and deterioration, and is non-toxic and safe, meeting the standards for food contact materials.

·Disposable items: PGA can be used to produce biodegradable shopping bags, tableware, and courier packaging, meeting the demand for plastic substitution.

·Functional packaging: By compounding with other natural polymers such as starch and chitosan, PGA packaging materials can be endowed with antibacterial, fresh-keeping and other functions, enhancing product added value.