(1) Completely aseptic packaging
It means that liquid food is filled and packaged in an aseptic environment with aseptic packaging materials after sterilization. This type of packaging can be used for many foods:
Generally, milk that requires a long shelf life can be packaged completely without bacteria. It is sterilized by ultra-high temperature for 2-6 seconds at a temperature of 130-150℃ before aseptic filling. These aseptic filled milk, stored for one month at room temperature (20-27°C), there is no growth of microorganisms and no change in quality.
2. Citrus juice, apple juice and other beverages
The aseptic filling method of fruit juice drinks is basically the same as that of milk. However, since the pH value of the fruit juice is below 4.5, the objects of sterilization treatment are yeast, mold, and lactobacillus. The maximum heating temperature of the sterilization device is generally below 100°C. After a few seconds of sterilization, the container can be filled and packaged after cooling to 20°C.
3. Tomato sauce
The aseptic filling and packaging method of tomato sauce is to raise the tomato sauce to a specified temperature instantaneously by jet heating, and rinse inside the pressure reducer to remove the excess water in the tomato sauce and cool it. The temperature for rapid sterilization is 90-95°C, and it can be filled into sterilized packaging containers when quickly cooled to 40°C.
(2) Semi-sterile packaging
It refers to solid foods that are difficult to completely sterilize, such as sausage slices, bacon slices, pork and beef mixed sausages, cakes, etc., to suppress the initial bacterial count and use sterile materials to package in a sterile room, and then carry out refrigerated circulation wrapping method.
The cake baked from the continuous baking oven is cooled in a sterile room, cut into a certain size in a dicer, and then air-packed. Put it into the outer packaging container in the outer packaging room. The temperature in the outer packaging room should be adjusted at 15-18°C.
Such a cake packaged in a sterile room with K/PET/PE packaging materials, if carbon dioxide gas is injected, can be stored for 25 days at a temperature of 30°C and a relative humidity of 95%. 2. Processed meat products After processed meat products are vacuum-packaged in a sterile state, they are usually not heated, so the food tastes good. Recently, inflatable packaging under aseptic conditions has appeared. This packaging method needs to be distributed and sold at low temperatures.
2. Home cooking
In order to improve the preservation of salads abroad, aseptic packaging technology is also used, that is, the salads are made aseptically as possible and aseptically packaged in the aseptic room.