Steam cooking vacuum bag food processing sterilization process food raw materials, processing, bagging, hot melt sealing, inspection, heating sterilization, drying and packaging. Among them, bagging, sealing, sterilization of the three processes and cooking bag itself has the closest relationship.
(1) Bagging
First of all, the amount of bagging and cooking vacuum bag capacity to match, the amount of bagging most of the sealing easily caused by contamination, do not load the contents of the large or bone, or affect the sealing, and even puncture the composite membrane caused by leakage and lead to food corruption. Second, maintain a certain degree of vacuum when bagging, to prevent the bag of food oxidation, browning, flavor change. Again, when bagging to prevent sealing contamination, if the sealing part of the juice, water droplets attached to the inner layer of the sealing part of the heat sealing to produce vapor pressure, when the sealing pressure is eliminated, the immediate production of bubbles and make the sealing part of the expansion, resulting in the sealing part of the seal. In addition, grease and fiber attached to the sealing part, the part area can not be sealed. In the pressurized sterilization and pressurized cooling, resulting in secondary contamination and leakage of corruption. To prevent contamination of the mouth of the bag, one is to control the amount of bag filling, at least 3 ~ 4cm away from the mouth of the bag; the second is the filling device is suitable for the product characteristics; the third is the use of winged protective sheet inserted into the bag to prevent contamination; the fourth is the bag should be able to fully open; the fifth is the bag can be positioned.
(2) sealing
General use of hot melt sealing: heating temperature of 180 ~ 220 ℃, pressure of 30N/cm?, time 1s, cooling under pressure. Hot melt sealing should be prevented from sealing wrinkles, first, the mouth of the bag should be flat; second, the two sides of the sealing knife should be flat and keep parallel; third, the contents should be limited.
(3) heating sterilization
Steaming vacuum bagged food and other food microbial corruption of the same type, heating sterilization process according to the characteristics of the steaming vacuum bag appropriate changes.
High-temperature sterilization process
Steaming vacuum bag pressure heating and high-temperature sterilization process can be divided into intermittent and continuous. The heating medium can be saturated steam, steam-air mixture or hot water. Due to the low mechanical strength and sealing strength of steaming vacuum bag material, the sterilization equipment must use counter-pressure sterilization. For cooking bags, the main use of fixed pressure counter-pressure mode, this counter-pressure control is in the sterilization of the heating stage began to pass into the compressed air.