Packaging and sterilizing technology for canned soft canned meat

Canned meat generally refers to meat and poultry meat, fish and other meat as the main raw material, adding seasonings and spices, processed canned products. Meat canned foods with soft packaging as a packaging container have become more and more widely used because of their convenience in food and storage at room temperature.

In the flexible packaging, a representative retort pouch made of three layers of material—aluminum foil pouches, the outer layer material is a polyester film (PET), the intermediate material is an aluminum foil, and the inner layer material is polypropylene (PP). . Aluminum foil bag thickness of about 0.15 mm, with high temperature, high pressure, opaque, airtight, good heat sealing properties and easy to use and so on. The following is the experience of the author in the production practice, through the vacuum packaging, high temperature sterilization technology applied to soft packaging canned meat production process.

The purpose of the vacuum packaging vacuum packaging is to extract the air in the aluminum foil bag to make the food in the bag vacuum, prevent the aluminum foil bag from being deformed or damaged during the high temperature sterilization, and prevent the change of color, smell, taste and aerobicity of the food in the bag. The proliferation of bacteria to avoid food spoilage. The equipment used for vacuum packaging is a vacuum packaging machine, which is mainly composed of a vacuum pump and a studio. Generally divided into automatic, double room, single room three forms.

The working parameters of vacuum packaging are heat sealing temperature, air extraction time and heat sealing time. Different working parameters are selected according to the different materials, sizes and thicknesses of the flexible packaging. For example, a three-layer aluminum foil bag with a specification of 150×200 can be loaded with a net weight of 250 g of cooked meat. The operating parameters are as follows: the heat sealing temperature is set to mid-range, the pumping time is set to 27 seconds, and the sealing time is set to 2. 7 seconds. Under this condition, after vacuum packing, the vacuum degree in the aluminum foil bag is 0.085-0.09 MPa, and the vacuum effect is good, and the specified requirements are achieved.

After the vacuum packaging is completed, the aluminum foil bag should be tight and airtight, tightly sealed, and no damage to the bag surface. Otherwise, the bag must be changed and repacked to avoid unqualified products.

The purpose of high-temperature sterilization and high-temperature sterilization is to kill the bacteria contaminated in the food and destroy the enzymes in the food so that the shelf life of the food is more than one year at room temperature. The high-temperature sterilization is carried out using high-temperature steam, and the equipment used is Sterilizing pan, mainly composed of pan body and pan door. Generally divided into automatic, horizontal, vertical three forms. The supporting equipment includes steam boilers, air compressors, and water pumps.

The operating parameters of high temperature sterilization are sterilization temperature, temperature increase time, constant temperature sterilization time, cooling time and back pressure pressure. Different working parameters are selected according to the net content of soft canned meat cans. For example, the sterilization formula for a 250-gram aluminum foil bag canned meat can be expressed as 15'-30'-25'(back pressure 0.15MPa)/121.5°C. The specific meaning is: 121.5°C means the specified sterilization temperature; 15 'Indicates that the heating time is 15 minutes, that is, after the sterilizing pot containing the canned meat inside is closed, the high-temperature steam is introduced, and the time required for the pot to rise from the initial temperature to 121.5°C; 30' means that the constant temperature sterilization time is 30 minutes. , that is, the pot maintains a temperature of 121.5°C at this temperature; 25' denotes the cooling time, that is, high-pressure cooling water is injected into the pot, and the temperature in the pot drops from 121.5°C to the temperature of the shipment (generally The time required for 30°C is 25 minutes; when the back pressure is 0.15 MPa, it is necessary to inject compressed air to ensure that the pressure in the boiler is not lower than 0.15 MPa until the temperature is reached.

When the temperature in the pan drops to the specified delivery temperature, the cooling water can be stopped, and the drain valve and the exhaust valve can be opened to empty the pan before the pan door can be opened. After the sterilization is completed, inspections are also required. The soft canned meat can be placed in a reservoir, and sinks into the bottom of the water as qualified products; floated as unqualified products (caused by broken bags), accounting for about two-thousandths of a mill, practice Prove that this is a proven method.

In short, after vacuum packaging and high-temperature sterilization, aluminum foil pouches can be packaged according to GB4789.26-1994 food hygiene microbiological inspection, canned food commercial sterility test standard test, the microbiological indicators can fully meet the "commercial sterile" national standards Requirements, at room temperature, its shelf life of up to one year or even longer.