The cold storage packaging and cryopreservation of food can reduce the respiration of various fresh food cells and prevent the over growth and development of fresh food cells from ripening and over ripening, resulting in the decay and deterioration of food, fresh vegetables and fresh fruits; On the other hand, refrigerated and frozen food also inhibits the activity ability of microorganisms, which is the main factor causing food corruption, and produces the so-called bacteria purification effect, which can prolong the shelf life of food. Therefore, the method of storing videos in refrigerated and frozen packaging is widely used.
Refrigerated frozen food can be divided into naked refrigeration and packaging refrigeration.Naked refrigeration is suitable for large quantities of large foods, such as pork, beef, chicken, duck, a large number of fruits and vegetables. As the humidity is also very low at low temperature, humidity control treatment should be done in the warehouse, otherwise the loss of a large amount of moisture will dry the food and lose the original fresh taste. The simplest way is to cover the surface. The use of plastic film with low air and moisture permeability can prevent the loss of water, and it is also easy to operate mechanically in the freezer.
Cold storage under packaging is usually combined with aseptic packaging, deaeration packaging, gas replacement packaging and other packaging methods, which can greatly prolong the service life of food. Refrigerated frozen packaging materials can be selected. They must still have good drawing strength, impact strength, puncture resistance, heat sealing strength and flexibility at low temperature, so as to maintain good strength and toughness.
At low temperature, the moisture permeability of plastic film is decreasing and the moisture resistance is improving. With the increase of time, the oxygen concentration in the packaged food bag will increase, but the increase of oxygen concentration at low temperature decreases. Of course, if the food packed in the bag has the function of cell respiration, then oxygen will be reduced and carbon dioxide will be increased. Because the cells breathe and absorb oxygen and emit carbon dioxide gas, the better the barrier of the film, the easier it is to achieve the cell preservation state, that is, when the oxygen content is less than 2% and the carbon dioxide is more than 8%, the cells are in hibernation state, so as to prolong the preservation time.
Frozen food packaging can be used for frozen storage of the following foods: yogurt, lactobacillus beverage, cream, cheese, soy milk, fresh noodles, tofu, ham, sausage, pickled dried fish, smoked fish, aquatic products, pickles, assorted cooking, general cooking, hamburger, raw pizza etc.
Post time: Jun-21-2022