The barrier property of modified atmosphere packaging film is the core factor that determines the preservation effect, and directly affects the material exchange process between food and the external environment. In food preservation, the penetration of gases such as oxygen, carbon dioxide, and water vapor will accelerate food oxidation, microbial reproduction or water loss, and the barrier property of packaging film is the first line of defense against these problems.
Good barrier property is first reflected in the control of oxygen. Oxygen is one of the key factors that cause food deterioration. It will promote fat oxidation and rancidity, pigment fading, and provide a living environment for aerobic microorganisms. High barrier modified atmosphere packaging film can significantly reduce the amount of oxygen entering, slow down the oxidation reaction inside the food, and inhibit the growth of microorganisms such as mold and bacteria, thereby extending the shelf life of food.
The regulation of carbon dioxide also depends on the barrier property of packaging film. In the process of modified atmosphere packaging, a certain proportion of carbon dioxide is filled to inhibit the growth of microorganisms, especially the inhibition effect on mold is significant. However, if the barrier property of the packaging film to carbon dioxide is insufficient, the gas will easily escape quickly and cannot maintain a stable concentration in the package, and the preservation effect will be greatly reduced.
The barrier property of water vapor cannot be ignored. For fresh fruits and vegetables, baked goods, etc., the moisture content is directly related to the taste and quality. If the packaging film cannot effectively prevent the entry of external moisture, the food may become moldy due to moisture; on the contrary, if the packaging film is too breathable, the internal moisture of the food will be lost too quickly, which will cause shrinkage, hardening, and loss of original flavor.
The adaptability of the barrier property of the packaging film to the type of food is the key to the preservation effect. Different foods have different requirements for the gas environment. For example, meat preservation requires a higher oxygen content to maintain color, while fresh-cut fruits and vegetables require a low-oxygen and high-carbon dioxide environment to inhibit respiration. Only by selecting a packaging film with appropriate barrier properties according to the characteristics of the food can the internal gas composition be accurately controlled to achieve the best preservation effect.
In addition, the barrier property of the packaging film will also change with time and environmental conditions. In a high temperature and high humidity environment, even a packaging film with good initial barrier properties may reduce the preservation effect due to the decline in material performance. Therefore, in addition to selecting high-quality packaging films, storage and transportation conditions must also be considered to ensure the stability of barrier properties.
The barrier property of modified atmosphere packaging film is closely related to the preservation effect. It builds a stable internal environment for food by precisely controlling the exchange of gas and water. From raw material selection to practical application, each link needs to be optimized around barrier performance to truly give play to the preservation advantages of modified atmosphere packaging and ensure the quality and safety of food.
