What is dangerous meat after freezing
'11.02.2019'
Source: Clever
With the advent of individual freezers, frozen meat has become a familiar product in any family. It is often purchased for the future, filling the freezer to capacity. And in the villages where their livestock are slaughtered, the freezer is the only way to keep the farmed one.
“And this is one of the safest ways,” said Elizabeth Andress, a food safety specialist at the University of Georgia in Athens. In her opinion, nothing happens in the freezing process that could affect the quality of the meat. But after defrosting, one cannot be sure about it, writes Clever.
But Dag Goff, a professor of food science at the University of Guff in Ontario, has a different opinion. He explains that meat has its own microbiological and physico-chemical indicators, and in the process of freezing, they will in any case change. For example, during freezing, chemical and enzymatic reactions occur in meat, which may well cause a loss of product quality. And the higher the storage temperature, the faster these reactions take place. So, at minus ten degrees on the Celsius scale, myoglobin oxidizes most rapidly.
Also during freezing due to the oxidation of phospholipids, fat is oxidized both in fat deposits and in lean meat, and specifically in intramuscular lipids. Due to oxidation, the meat taste may become rancid. Moreover, meat that has a high percentage of polyunsaturated fatty acids is subjected to more oxidation. On this basis, pork is most susceptible to oxidation, beef is slightly less so and mutton is even less so. But the oxidation process is very long. Therefore, in order not to spoil the meat, it is necessary to keep it in a deep freeze for a certain time. For meat, the maximum period is usually 12 months.
Often, according to Doug Goff, freezing is used to destroy pathogenic protozoa in meat, as well as nematodes, cestodes - they are sometimes found in beef and pork.
For example, the larvae of flatworms die at a temperature of minus ten degrees and below for ten days. However, there are many simple ones that simply “fall asleep” in the process of freezing. It is only necessary to defrost the meat - and they come to life again and begin to actively multiply. After re-freeze-defrost, this process is twice as fast.
Rick Holly, a microbiologist for food safety at the University of Manitoba, says that when it comes to frozen meat, the main thing is to unfreeze it properly. It is necessary to immerse it in cold water until it is completely thawed and only then to cook. Thus its useful properties are better preserved and the quality suffers minimally.
Scientists VNIIMP them. V.M. Gorbatov, who specializes in research and development in the meat industry, did a great job of studying the properties of frozen meat. In two years, they have done more than 2700 analyzes of such meat and concluded that with proper freezing, no loss of meat quality occurs. But only with a single freeze.
If you do it again, then only the fibers will remain from the meat, it completely loses any useful properties, and most importantly, all the protein goes into ice crystals, and after defrosting it simply flows along with the liquid. If there is such meat all the time, then the body loses a lot of nutrients.
Experts suggest paying attention to frozen meat when it is thawed. Fresh-frozen meat has a bright red color with a grayish tint, which is the same on the surface and on the inside. Re-frozen meat is dark red on the surface and cherry red in the cut. If it is a primary freeze, then the color of the meat, freed from the ice, changes color to red. But if the meat was placed in the freezer not for the first time, its color will remain unchanged.
