What does meat that has been frozen for hundreds of thousands of years taste like?

Image source: Yale.edu

On January 13, 1951, members of the Explorers Club gathered in New York for a grand party.

This annual gathering features explorers' expeditions around the world, showcasing special collections brought back from around the world.

A fireplace on the first floor of the Explorers Club headquarters in New York. Image credit: Rhododendrites - wiki

Each dinner is the climax of the party, and club members can enjoy a variety of exotic meals.

The dinner in 1951 was even more shocking. The most attractive item was a piece of mammoth meat that was said to be 250,000 years old and came from Alaska .

The meat was said to have been brought back from Akutan Island by club member Father Bernard Hubbard.

When he discovered it, the mammoth was still frozen.

Bernard Hubbard, the "Father of Glaciers". Image source: Wiki

Hubbard was an American geologist and explorer who had led expeditions into Alaska and the Arctic many times and was known as the "Glacier Father."

In the far north, due to the cold climate, it is common to find mammoths that are completely preserved. Later, scientists did taste the meat of mammoths and said that it tasted like sand or rotten beef jerky. In short, it was not very delicious.

But in 1951, the hors d'oeuvres served to these distinguished members were not actually mammoth meat. After DNA analysis, scientists later discovered that the meat actually came from a green sea turtle.

A small specimen of "mammoth" meat is preserved at the Yale University Peabody Museum of Natural History, but it is labeled "Giant Ground Sloth" rather than "Mammoth." Image source: cgab.yale.edu

What happens to meat after being frozen? Why does it have a strange texture and taste like "sand" or "rotten beef jerky"?

Physical changes

As the freezing time increases, the texture of most meats will change. The most obvious change is physical, which is mainly related to the water content of the meat .

When meat is frozen, the water in it is frozen into small ice crystals, which expand in volume. If you observe it under a microscope, you will find that the sharp edges of these small ice crystals pierce the protein molecules like a blade , destroying the structure of the cell membrane. In this way, the taste of the meat is greatly reduced.

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When the cell membrane is punctured, the water inside the cell can flow out freely . Therefore, a very obvious characteristic of frozen meat is that it will ooze blood, which is especially obvious after thawing.

Along with the blood, some acidic substances such as minerals and small proteins also seep out, which will cause the pH value of the meat to decrease.

At the same time, the concentration of soluble substances such as carbohydrates, proteins, vitamins, etc. in the meat will also increase , which constitute the material basis for various chemical reactions in frozen meat.

Temperature is a key factor affecting this series of changes. According to scientists, if you want to store meat for a long time and on a large scale, the best freezing temperature is -40℃.

Chemical changes

Chemical reactions that occur in frozen meat can cause lipid peroxides and hydroperoxides to form in the meat.

Lipid peroxidation is the process of oxidative degradation of fat substances. During the reaction, unsaturated lipids first combine with free radicals (such as hydroxyl groups) to produce lipid free radicals, which then react with oxygen molecules to produce lipid peroxides.

Lipid oxidation process. Image source: wiki

These peroxides will further undergo oxidation reactions to produce substances such as valeraldehyde, hexanal and malondialdehyde (MDA), which are the culprits that cause the meat to have a rancid smell.

The lipid peroxidation process can also change the color, texture, and even nutritional value of meat , and has the greatest impact on meat quality.

The nutritional value of meat depends largely on the fat content and fatty acid composition, and the distribution of fatty acids will change during continuous freezing, for example, unsaturated fatty acids will be converted into saturated fatty acids.

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Scientists have found that the overall properties of pork stored at -10°C for 7 months do not change much . But if it continues to be frozen, you will gradually be able to tell from your senses that "this meat is definitely not delicious."

Others have compared the changes in tenderloin and pork belly stored at -23°C for the same period of time and found that there is no significant difference between the two types of meat with different fat contents . This shows that peroxidation occurs in both lipids and myoglobin, and they affect the texture of the meat.

Microbial changes

Most frozen meat labels give a recommended shelf life, which mainly takes into account the texture, color, and smell of the meat, but rarely refers to microbial safety.

The growth of microorganisms mainly depends on a series of operations when slaughtering animals, as well as subsequent processing and preservation methods, etc.

During the freezing process, about 60% of the microorganisms will be killed , while the remaining microorganisms will continue to multiply and even slowly increase.

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A greater impact from these inexorable microorganisms occurs during the thawing process before we eat the meat.

Scientists have found that after thawing, the types of microorganisms surviving in the meat are almost the same as before freezing, but in smaller quantities. If the meat is left for a period of time after thawing, these microorganisms can completely return to their initial values.

Among the microorganisms that cause meat spoilage, a very important category is Gram-negative bacteria , which often make us sick. The most representative of them is Escherichia coli.

So if you were to eat a piece of meat that had been frozen for a long time, it would probably taste terrible, taste sour, be a weird color, smell rancid, have little nutritional value, and contain microorganisms that you would never want to eat.

The following are some raw meat storage times recommended by the US Foodsafety website and the US Department of Agriculture:

Trying everything will only harm you.

References

[1]https://www.adn.com/alaska-life/2023/05/07/mystery-meat-of-1951-did-an-exclusive-club-eat-a-frozen-woolly-mammoth-from-the-aleutians/

[2]Medić H, Kušec ID, Pleadin J, et al. The impact of frozen storage duration on physical, chemical and microbiological properties of pork[J]. Meat Science, 2018, 140: 119-127.

[3]Leygonie C, Britz TJ, Hoffman L C. Meat quality comparison between fresh and frozen/thawed ostrich M. iliofibularis[J]. Meat Science, 2012, 91(3): 364-368.

[4]https://www.foodsafety.gov/food-safety-charts/cold-food-storage-chart

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Source: Bringing Science Home

Author: Ziv Editor of Everything Magazine

Review丨Editor of Skin Magazine

Editor: Jin Yufen (Intern)

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