The Choice of Packaging Materials Directly Affects the Shelf Life of Your Products!

Vacuum packaging technology, MAP packaging technology and deoxygenation packaging technology have increasingly catered to the major trend of market development. Food manufacturers not only make great efforts in the healthiness, nutrition and flavor of their products, but also keep innovating food packaging, in addition to more exquisite and more distinctive appearance designs. But did you know that differences in packaging materials and methods, especially barrier performance, will directly affect the shelf life of your products.

From the perspective of food safety, packaging has two functions: one is moisture prevention, and the other is oxidation prevention.

I. Vacuum packaging

Vacuum packaging means mechanically extracting the air from the package before sealing. It is currently very common in the food industry, such as ham, sausage, beef jerky, pickles, soy products, preserved fruits, etc. Taking dried tofu as an example, the preservatives allowed for use in the national standard are only potassium sorbate and sodium diacetate, but their mold-prevention effect is not ideal. Usually, vacuum packaging is combined with deoxygenation to inhibit the growth and reproduction of microorganisms and prevent oxidation, discoloration and off-flavor, greatly extending shelf life. But vacuum packaging also has the following problems:

Bloated bags, caused by incomplete sterilization or poor barrier properties and sealing performance of packaging materials.

Off-flavor of the product, usually turning sour, caused by microbial reproduction or the light transmittance of packaging materials, the external environment, etc.

Air leakage, caused by poor barrier properties and sealing performance of packaging materials.

II. MAP packaging (gas-flush packaging)

Many foods are not suitable for vacuum packaging because they are fragile, prone to caking or deformation under pressure, and must use gas-flush packaging, such as bread, cake, meat floss cake, mung bean cake, potato chips, dehydrated vegetables, etc. Gas-flush packaging can not only remove oxygen and preserve quality, resist pressure and block gas, but also effectively prevent food from being crushed and deformed under pressure, without affecting the appearance and printed decoration of the packaging bag. However, gas-flush packaging also has the following problems:

Gas being absorbed and the package being vacuum drawn, caused by reproduction of heat-resistant bacteria, etc.

Mold growth, caused by microbial contamination and poor barrier properties of packaging materials.

Air leakage, caused by poor barrier properties and sealing performance of packaging materials.

III. Conclusions and recommendations

1. Packaging materials are very important for food preservation. Packaging materials with excellent barrier properties (airtightness) must be used, because there are many pores invisible to the naked eye on the packaging that allow the contents to exchange with the air. Three-side sealed bags made of double-layer composite film or three-layer aluminum foil composite film are usually used. The thickness of the composite film is between 60-96μm, and it needs to have good heat seal properties and physical and mechanical strength.

Note: The inner substrate of the composite film is commonly polyethylene (PE), and the outer substrate is commonly oriented polypropylene (OPP), polyester (PET), nylon (PA), etc. Some high-fat foods are best packaged with light-blocking packaging; a very thin layer of aluminum foil (AL) can be laminated between the inner and outer substrates,

1. Choose good preservatives and freshness-retaining agents. If chemical preservatives do not achieve the desired effect in certain foods, efficient natural preservatives can be used. At present, Guangzhou Baiqing Company has developed a natural plant extract extracted from food raw materials, which is completely natural, safe and non-toxic, and is used in various leisure foods for mold prevention and freshness retention.
2. Avoid cross-contamination; sterilization during pretreatment must be thorough.
3. Manufacturers should select suitable packaging materials according to product characteristics, and avoid organic solvents in packaging materials penetrating into food.