The Application of Biodegradable Plastics in Food Packaging

     With the tightening of environmental regulations and the enhanced green consumption awareness among consumers, the problem of white pollution caused by traditional non-biodegradable plastic packaging has become increasingly prominent. Biodegradable plastics, due to their environmentally friendly characteristics, have gradually become the mainstream material for the transformation and upgrading of the food packaging industry, and are widely used in all categories of food packaging, such as fresh produce, cooked food, beverages, and snacks.

     Biodegradable plastics are mainly divided into two categories: biobased biodegradable and petrochemical-based biodegradable. The commonly used raw materials on the market are PLA (polylactic acid), PBAT, and starch-based modified plastics. PLA is derived from the fermentation extraction of crops such as corn and cassava, and is strong in rigidity and has excellent transparency, which is mainly used for disposable lunch boxes, cold drink cups, and pastry packaging boxes; PBAT has good flexibility and is resistant to low temperatures, and is often combined with starch to make fresh produce preservation bags and fruit and vegetable wrapping films; starch-based biodegradable plastics have a low cost and are suitable for fast food packaging bags and snack outer packaging, and are the preferred material for affordable food packaging. Under natural soil and industrial composting conditions, these materials can be decomposed by microorganisms into carbon dioxide and water within several months to one year, without contaminating the soil and water sources with plasticizer residues, thus solving the environmental pain point of the difficulty in degrading discarded food packaging at its source.

     In actual food packaging scenarios, the implementation results of biodegradable plastics are remarkable. In the fresh produce sector, supermarket fresh produce preservation bags and meat trays gradually replace traditional PE plastic bags. The biodegradable film in low-temperature environments can maintain the breathable performance and delay the spoilage of fresh produce; in the catering industry, takeout packaging boxes, disposable straws, knives, and forks have fully adopted biodegradable materials. The plastic limit orders in many places have clearly prohibited non-biodegradable disposable tableware, accelerating the popularization of biodegradable packaging; in the beverage industry, PLA biodegradable bottles are used for tea cups and mineral water bottles, and the sealing films for fruit juice and yogurt are also replaced with composite biodegradable films; in the snack industry, modified biodegradable plastics are used for the inner packaging of crispy snacks and independent small packaging of candies, balancing moisture prevention and environmental protection attributes. At the same time, the biodegradable materials have undergone food-grade safety modification, meeting the national food contact material safety standards, without containing heavy metals and harmful additives, and will not cause harmful substances to leach out when heated, ensuring food safety.

     At present, there are still shortcomings in biodegradable food packaging: the production capacity of raw materials is limited, and the price of raw materials is higher than that of ordinary plastics, resulting in an increase of about 30% to 60% in the cost of packaging products; some pure PLA materials have a low heat resistance temperature, and when used to hold hot food, they are prone to softening and deformation, requiring optimization of performance through PBAT blending modification; the degradation speed in natural environments is greatly affected by temperature and humidity, and the natural outdoor degradation period is relatively long at room temperature. To address these problems, the industry continuously optimizes modification formulas, using agricultural and forestry waste residues to prepare biobased raw materials to reduce production costs, improving heat resistance and waterproofing processes, and enhancing product adaptability.

     In the long term, under the continuous implementation of national plastic limit policies and the iterative development of biochemical technology, biodegradable plastics will continue to occupy the market of traditional plastic packaging. In the future, through large-scale production of raw materials and refined modification of formulas, biodegradable food packaging will achieve cost reduction and performance improvement, covering all packaging categories in the food upstream and downstream, and playing a key role in reducing white pollution and promoting the green and sustainable development of the food industry.