Oxidation, rancidity, peculiar smell

　　Most foods containoil, proteins and other ingredients. When these ingredients are oxidized exposingto oxygen, decomposed by microorganisms, and subjected to high temperatureoxidation, the package will produce small molecules of acid, release peculiarsmell, and cause the acid value of the food to exceed the standard resulting inrancidity. Packaging of substandard quality will cause the above Issues:

1) Poor barrier properties - such as the poor oxygen barrier properties of packaging materials, causing oxygen to slowly penetrate into the packaging during long-term storage. In addition, packaging composite films with poor composite strength have poor oil barrier properties, contacting with oil will cause delamination of the composite film, resulting in a decrease in the overall oxygen barrier of the package.
2) Poor sealing performance – such as poor sealing properties at the sealing site caused by incorrect heat sealing parameters, as a result, oxygen enters the package through the heat sealing site. Or because the packaging is weak to high temperatures, the package leaks during sterilization, and the oxygen enters the package.
3) Inferior physical and mechanical properties - such as packaging materials are weak to punctures; or pinholes, creases, and damages on the packaging materials due to the kneading or squeezing during production and storage. If the damages were not discovered in time, the food would be exposed to a large amount of oxygen which may lead to oxidation and deterioration.