Vacuum packing is the main function of oxygen in order to prevent food spoilage, its principle is simple, because food metamorphism causing mold mainly caused by the activity of microorganism, and the survival of most microorganisms (e.g., mold and yeast) is need oxygen, and vacuum packing is using this principle, the packaging and food within the cell oxygen smoke, lose microbial "survival environment".Experimental results show: when the concentration of oxygen in the packaging 1% or less, microbial growth and reproduction rate fell sharply, the oxygen concentration of 0.5% or less, most microbes will be reined in and stop breeding.(note: vacuum packing can inhibit anaerobic bacteria breeding and enzyme reaction caused by food metamorphism and discoloration, so still need to combine with other auxiliary methods, such as cold storage, frozen, dehydrated, high temperature sterilization, irradiation sterilization, microwave sterilization, salting, and so on.
Vacuum deaeration besides inhibiting microbial growth and reproduction, another important function is to prevent the oxidation of the food, because the oil kind food contains a lot of unsaturated fatty acid, by the effect of oxygen oxidation, sour food, deterioration.In addition, the oxidation also make vitamin A and vitamin C loss, food pigment in the volatile substances by the role of oxygen, make the color darker.So oxygen can effectively prevent food spoilage, maintain its color, aroma, taste and nutritional value.Small vacuum packaging machine as long as can reach a certain vacuum degree, the same effect.
In addition to the main function of vacuum packaging vacuum packaging quality of deoxidization function, main and compressive strength, the air resistance, the preservation effect, can more effectively to make food for a long time to keep the original color, aroma, taste, shape, and nutritional value.In addition, there are many food should not be using vacuum packaging, vacuum packaging must be used.Such as crisp fragile food, nutrition food, easy deformation and oil food, there are sharp edges or high hardness will puncture bag food, etc.Food vacuum packaging machine, vacuum packaging, packaging bags inside air pressure is greater than the atmospheric pressure outside packing bag, can effectively prevent the crushing of the food compression deformation, does not affect the packaging and printing packaging appearance.
Vacuum packed in vacuum and then filling the nitrogen, carbon dioxide, oxygen, single or 2-3 kinds of gas mixture of gases.Nitrogen is inert, filling effect, make the bag to maintain positive pressure, in order to prevent the outside air into the bag, bag of food plays a protective role.Carbon oxide gas or water can dissolve all kinds of fat, formation of weak acid, carbonate, corruption has inhibitory activity of bacteria and other microorganisms.Oxygen could inhibit the growth of anaerobic bacteria breeding, keep fruits, vegetables, fresh and color, high concentration of oxygen to keep fresh meat, its bright red.