Causes of Bulging Vacuum Packaging Bags

Vacuum packaging is designed to remove internal air and maintain a flat and compressed state for long-term food preservation. However, bag bulging, also known as ballooning, frequently occurs during storage and transportation. This phenomenon refers to the expansion of the packaging bag with accumulated internal gas, which completely breaks the original vacuum state. Bulging is an obvious warning signal of packaging failure and potential food spoilage. Understanding the specific causes of vacuum bag bulging helps users identify food safety hazards accurately and avoid accidental consumption of deteriorated products.

Microbial fermentation and reproduction is the primary cause of packaging bulging. Vacuum-packaged food still contains trace microorganisms or bacterial spores that survive the sterilization process. When the food is stored at inappropriate temperatures, such as high room temperature or prolonged exposure to heat, dormant microorganisms will become active. Bacteria and molds decompose organic substances in food, including protein, carbohydrates and fat, and produce a large amount of carbon dioxide, hydrogen and other gases. These gases continuously accumulate inside the sealed bag and cannot be discharged outward, gradually causing the packaging to bulge. This situation is extremely common in cooked meat, bean products, pickled vegetables and high-moisture grains.

Packaging damage and poor sealing are another major inducement. Tiny pinholes, cracked edges and damaged composite layers caused by extrusion, collision and friction during transportation allow external air to penetrate into the bag slowly. In addition, unqualified heat sealing in the production process will lead to incomplete closure of the bag mouth. External air and bacteria continuously enter the packaging, not only destroying the vacuum environment but also accelerating gas generation from food deterioration. Even dry food will absorb moisture and oxidize, resulting in bulging and quality deterioration.

Minor environmental factors also trigger slight bulging. Severe temperature changes and atmospheric pressure fluctuations will cause subtle gas expansion inside the bag. Nevertheless, this kind of bulging is slight and will recover after placing in a constant-temperature environment. In contrast, bulging caused by microbial growth is irreversible. In short, most bulging vacuum bags indicate food spoilage and must be discarded directly to ensure food safety.

Google Academic & Standard Citation Formats

1. GB/T National Standard Citation

GB/T 30768-2014. General safety specification for food plastic packaging materials and products[S]. Beijing: China Standards Press, 2014.

2. APA 7th Edition

Wang, H. (2024). Causes and safety risk assessment of bulging vacuum food packaging. Food Packaging Science.

3. MLA 9th Edition

Wang, Hao. Causes and Safety Risk Assessment of Bulging Vacuum Food Packaging, Food Packaging Science, 2024.