Sterilization Technology Of The Food In Retort Pouches

Introduction to news dynamic points: Retort pouch is a composite plastic film bag that can be heated. It has the advantages of can container and boiling water resistant plastic bag. Therefore, it is also called "soft can". After more than ten years of use, it has proved to be an ideal sales packaging container.

Structure and material of retort pouch

The retort pouch is mostly made of three-layer materials. The representative retort pouch structure is: the outer layer is PET film for reinforcement; The middle layer is aluminum foil, which is used to prevent light, moisture and air leakage; The inner layer is RCPP film,which is used for heat sealing and contacting food.

Advantages and disadvantages of retort pouch

Advantages:

In terms of food packaging, compared with metal cans and frozen food packaging bags, there are many advantages on retort pouches:

① Maintain the color, aroma, taste and shape of food. The retort pouch is thin, which can meet the sterilization requirements in a short time, and preserve the original color, aroma, taste and shape of the food as much as possible.

② Easy to use. The retort pouch can be opened conveniently. When eating, put the food together with the bag into boiling water and heat it for 5 minutes to open it for consumption, or even eat it without heating.

③ Convenient storage and transportation. The retort pouch is light in weight, can be stacked for storage, and occupies a small space. After packaging food, the space occupied is smaller than that of metal cans, which can make full use of the storage and transportation space and save the storage and transportation cost.

④ Save energy. Due to the thin retort pouch, the lethal temperature of bacteria can be reached quickly during heating, and the energy consumption is 30 ~ 40% less than that of iron can.

⑤ Easy to sell. In addition, the sales volume of steamed or boiled food can be greatly increased according to different needs of customers.

⑥ Long storage time. The food packaged in retort pouches does not need to be refrigerated or frozen, and the shelf life is stable. It can be comparable with metal cans, which is convenient for sales and family use.

⑦ Low manufacturing cost. The price of composite film for making retort pouch is lower than that of metal plate, and its production process and equipment are very simple, so the price of retort pouch is lower.

Disadvantages :

The main reason is the lack of high-speed loading equipment, which has a certain impact on mass production.

Technological properties of retort pouch food

1) In order to prevent the leakage of liquid during opening, the filling rate of the contents is generally controlled at about 80% when cooking food in such plastic forming containers. Generally, after filling the contents, replace the empty part with inert gas such as nitrogen or carbonic acid to prevent discoloration or oil oxidation of the contents. At present, this method is widely used.

2) When these products are treated with general cooking and sterilization methods, due to the gas in the container, they are prone to expansion, bursting and damage to the sealing film during the treatment process, sometimes leading to the decline of commodity value and secondary pollution after sterilization.

3) In order to solve these problems, in the whole process of cooking and sterilization, especially in the heating and cooling process, the internal pressure of the container must be controlled to be equal to that of the sterilization device.

4) Even for bagged products, in order to maintain the shape of solid products such as corn, rice and noodles, some products sometimes adopt the method of gas replacement. However, the situation that liquid food is pumped and sealed after filling, while solid matter is vacuum packaged is still the mainstream. The method of replacing liquid products with nitrogen has no advantage. On the contrary, from the situation that it hinders heat transfer, the adverse factors are greater.

5) After heating and sterilizing the food filled in the sealed container, it can circulate at room