Let you fully understand at a glance, the process of pressure heating and high-temperature sterilization using the sterilization bags!
The pressure heating and high-temperature sterilization process for the sterilization bag can be divided into intermittent and continuous types. The heat medium can be saturated steam, steam-air mixture or hot water. Due to the low mechanical strength and sealing strength of the sterilization bag material, the sterilization equipment must adopt reverse pressure sterilization. For the sterilization bag, the main sterilization method is the constant pressure reverse pressure method, where compressed air is introduced at the beginning of the sterilization heating stage.
Food raw materials, processing, bagging, hot melt sealing, inspection, heating sterilization, drying and packaging. Among these, the bagging, sealing and sterilization processes are the most closely related to the sterilization bag itself.
Pressure heating and high-temperature sterilization process for the sterilization bag
(1) Bagging
Firstly, the bagging volume should match the capacity of the sterilization bag. The bagging volume is mostly prone to contamination during the sealing process, so do not pack large pieces or bone-containing contents, otherwise it will affect the sealing and even puncture the composite film causing leakage and food spoilage. Secondly, maintain a certain vacuum degree during bagging to prevent food oxidation, browning, and flavor variation. Thirdly, prevent contamination of the sealing part when bagging. If there is juice, water droplets adhering to the sealing part, the internal layer of the sealing part will generate steam pressure when the sealing pressure is eliminated, causing bubbles to form instantly and causing the sealing part to expand, resulting in a non-sealed area. If oils and fibers are attached to the sealing part, the area cannot be sealed. During pressure sterilization and cooling, secondary pollution and leakage spoilage occur. To prevent bag contamination, one is to control the bag volume, keeping at least 3-4 cm away from the bag opening; the filling device should be suitable for the product characteristics; three is to use wing-shaped protective sheets inserted into the bag during filling to prevent contamination; four is that the bag should be fully opened; five is that the bag can be positioned.
(2) Sealing
Generally, the heat melt sealing method is used: the heating temperature is 180-220℃, the pressure is 30N/cm², and the time is 1s. It is cooled under pressure. During heat melt sealing, prevent wrinkles in the sealing part. One is that the bag opening should be flat; two is that the two sides of the sealing knife should be flat and kept parallel; three is that the contents should be limited.
(3) Heating sterilization
The microbial spoilage types of the food in the sterilization bag are the same as those of other foods. The sterilization process for heating sterilization is appropriately modified according to the characteristics of the sterilization bag.
The pressure heating and high-temperature sterilization process for the sterilization bag can be divided into intermittent and continuous types. The heat medium can be saturated steam, steam-air mixture or hot water. Due to the low mechanical strength and sealing strength of the sterilization bag material, the sterilization equipment must adopt reverse pressure sterilization. For the sterilization bag, the main sterilization method is the constant pressure reverse pressure method, where compressed air is introduced at the beginning of the sterilization heating stage.
(Source: Huayin Flexible Packaging WeChat Official Account)