Frozen food thawing

Freezing does not kill the bacteria, but it greatly slows their multiplication rate. When frozen food thaws, bacterial growth speeds up, especially if we allow the food to reach room temperature. If we then decide to refreeze the food, there will be more bacteria than there were in the first place when we thaw the food again, and they ll keep on multiplying. Some people wonder why this should matter. After all, when we cook the food, the bacteria will be destroyed. Heat indeed kills many bacteria, but some varieties — staphylococcus, for one — produce a heat-stable toxin. 

Frozen Foods. Corrosion caused by the reaction of foods with aluminum containers is unusual if the products are handled and stored at 0°F or lower. However, the inevitable bad handling of frozen foods during commercial distribution causes undesirable thawing. In this condition, not only does the food deteriorate, but it can also attack the container. Such unwanted reactions can be effectively controlled by using coated aluminum containers. Since aluminum is highly compatible with frozen fruits and citrus juices, it has been used extensively as a liner for fiberboard composite cans, as complete aluminum cans, or as ends in combination with steel can bodies in the frozen food industry. 

Downey, G. (2002). Quality changes in frozen and thawed, cooked pureed vegetables containing hydrocolloids, gums and dairy powders. Int. J. Food Sci. TechnoL, 37, 869-877. 

Refrigeration In the event of a power loss, refrigerators will keep food cold for approximately 4 to 5 hours, if unopened. Blocks of ice or dry ice can be used to extend the life of food. Only foods that have a normal color and odor should be consumed, and perishable foods should be discarded after 2 hours at room temperature regardless of their appearance or smell. Frozen food can be kept frozen with dry ice, but once thawed must be immediately cooked or discarded. As with refrigerated food, frozen food that thaws and has been at room temperature for 2 hours must be discarded. 

Superabsorbent polymers are used as a liquid-absorber in food packaging systems. In these systems, the superabsorbent polymers absorb juice or water from fresh foods such as raw chicken, shellfish, and other meats or from frozen foods as they thaw. Chilled superabsorbent polymer gels may also be used as a dry-cooling medium. The water-swollen gel, contained in a durable plastic bag, is frozen and used to keep perishable foods cold. In addition to its liquid-water-absorption characteristic, superabsorbent polymers absorb water from the vapor state and therefore may be used to control humidity. 

In the field of food science, knowledge about disintegration of cell membranes is important if deterioration of meat quality by freezing and freeze-storage is to be more fully understood (3). The presence of membrane-bound enzymes in the muscle-press juice after freezing and thawing could lead to a method for differentiating between nonfrozen meat and frozen and thawed meat. 

From these equations, it is clear that an increase in temperature reduces the relaxation time. When the dielectric loss factor increases with the increasing temperature, food would experience a phenomenon known as thermal runaway. When frozen food is thawed with higher microwave power, certain area of the food would be overheated while other areas remain much cooler. Hence, it is important to maintain low microwave power for thawing frozen food to have a uniform thawing. 

Park, S.H., Ryu, H.S., Hong, G.P., and Min, S.G. 2006. Physical properties of frozen pork thawed hy high pressure assisted thawing process. Food Science and Technology International 12 347-352. 

Freezing method and freezing rate, storage conditions and temperature abuse, as well as thawing are factors influencing the quality of frozen foods (Chambers et al.,... 

Miao, Y, Kawai, M., Horibe, K., and Noguchi, A. 2003. Ohmic thawing of frozen food. Proceedings of the 4th Annual Meeting of Japan Society for Food Engineering, Vol. 30. Otsu City, Japan (in Japanese). 

Miles, C.A., Morley, M.J., and RendeU, M. 1999. High power nltrasonic thawing of frozen foods. Journal of Food Engineering 39(2) 151-159. 

C (40°F) and has been out of the freezer for no more than twenty-four hours. Do not refreeze shellfish, dishes containing cream, or cooked foods, because they are particularly prone to bacterial growth. You can often tell if a frozen food has previously been thawed its package will be frost-coated, because when the food thawed moisture escaped from it and then refroze. 

Uses Vise, builder, freeze/thaw stabilizer for frozen foods, dairy prods., meats, canned meats, salad dressings, ketchup, ice aeam, ready-made... 

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