The meat I bought jumped, what's going on? How to choose meat, you will understand after reading this

As the New Year approaches, many families begin to prepare New Year's goods, and pork, beef and mutton are indispensable for every household.

But recently I saw some netizens reporting that the beef and mutton that had just been slaughtered were still twitching!

So I was a little worried. What was going on? Was there a parasite in the meat? Is it ok to eat beef or mutton that is throbbing?

The beef jumps, what’s going on?

The central nervous system of an animal that has just been slaughtered and is very fresh has died, but the nerve endings around the muscles have not completely died, and the energy substance adenosine triphosphate (ATP) in the muscles has not been exhausted.

Therefore, under slight external stimulation, muscles can still twitch, which is also called "superstimulation reaction".

When the ATP in the muscles is exhausted, the muscle fibers will lock and will stop beating.

Therefore, if the meat is throbbing right after being slaughtered, it does not mean that there are parasites. It just means that the meat is very fresh and was slaughtered not long ago.

When buying meat, the fresher the better it tastes?

Some people like to eat freshly slaughtered pork, beef and mutton, preferably slaughtered in the early morning and cooked at noon or evening. In fact, this is not a scientific way to eat meat.

Although freshly slaughtered beef and mutton are very fresh, if they are not cooked immediately after slaughter and are left at room temperature for more than a few hours, they will gradually become tough and unpalatable. Why is this so?

It turns out that this is a change that occurs in all livestock and poultry animals a few hours after being slaughtered.

The meat that has just been slaughtered is called "hot fresh meat" and the meat is soft. However, if it is not put into the pot immediately and is not cooled down in any way, then in the next few hours to days, the meat will enter the "rigor mortis period" and the muscles will contract strongly, making the meat stiff.

Although we think the meat is very fresh, in fact, the meat at this time has a poor taste, hard texture, and is not delicious.

Someone may ask: If the "hot fresh meat" just slaughtered is quickly frozen, will it prevent the meat from hardening?

The answer is regrettable. "Hot fresh meat" is called "frozen meat" after being frozen for a short period of time. It will undergo stronger muscle contraction and have a rougher taste.

So is there any way to make fresh meat tender and tender again?

The method is: quickly store the fresh meat after slaughter at a low temperature of 0-4°C for 1-2 days, the meat will slowly become soft again, and it should always be kept in an environment of 0-4°C during subsequent processing, circulation and sales. This is what we usually call "de-acidified meat" or "fresh cold meat".

What changes will occur to fresh meat after it is left to stand?

What changes will occur in the meat during the process of becoming "acid-depleted cold fresh meat"?

1. The proteases naturally present in the meat will moderately break down the proteins, producing peptides and amino acids, thus making the muscles softer and easier to cut. The cut surface has a special aromatic smell, is easy to cook, and has a delicate and juicy taste.

2. Anaerobic respiration of muscle cells causes the glycogen stored in the meat to be broken down into lactic acid, which is further broken down into carbon dioxide, water, and alcohol, and then evaporates. Therefore, it is called "acid-free meat", which makes the meat delicious;

3. The ATP in the meat is broken down to produce phosphoric acid and hypoxanthine, producing substances that make the meat more flavorful.

So, not all fresh meat tastes good!

If freshly slaughtered meat is not put into the pot immediately, it is best to undergo a low-temperature cold chain treatment of 0-4°C for several days. Not only will the meat become delicate, soft, delicious and juicy, but it will also inhibit the growth of microorganisms and prevent meat corruption, greatly improving the quality and safety of the meat.

How to choose beef and mutton?

There are so many kinds of meat on the market. How should we choose fresh, high-quality, acid-free, chilled meat?

We can judge the quality of meat based on its color, appearance, smell, etc.

1. Take a look: "Acid-removing meat" is light bright red with a shiny surface; "non-acid-removing meat" is blood red, lacks luster on the surface, and is dark in color.

2. Smell it: The "sour meat" does not have a particularly strong fishy smell, but has a fragrant taste.

3. Press: "Acid-releasing meat" is elastic after pressing and can recover in time after pressing; while "non-acid-releasing meat" has poor elasticity and cannot recover in time after pressing.

Finally, I would like to remind everyone that it is best to buy high-quality cold fresh meat and cook it on the same day. If you really can't finish it, you can put it in the refrigerator at 0-4℃ for 2-3 days at most and eat it as soon as possible.

Expert of this article: Dou Pan, deputy director of the Clinical Nutrition Department, Peking University First Hospital, nutritionist

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