I bought fresh beef online, and was shocked when I cut it open! Was it tampered with?

A netizen bought a piece of expensive fresh beef on an online grocery shopping platform, priced at 81 yuan per kilogram.

When you open it, the color is incredibly beautiful, but when you cut it open, the color of the meat inside is obviously different.

Although the meat smelled normal, he was still worried that it had been tampered with.

There are many different opinions among netizens, and there are mainly two camps of view. One is the "black curtain camp": some say that preservatives were added, some say it is synthetic meat, some say it is dyed, and some say mysteriously "you know".

The other group is the "normal group". Some say it is air-dried, some say it has been stored for too long, some say it is due to refrigeration, and some say this is the normal color of fresh beef.

In the end, no one could explain why. The blogger later said, "The platform returned the money to me in the form of a coupon, but they explained that the beef was normal. I checked online and it said that stale beef would turn red on the surface..." (I really want to pretend that I don't understand and defend my rights)

Only one netizen got close to the truth. He noticed a key word on the product packaging, "modified atmosphere to lock in freshness". In fact, the secret lies here. Modified atmosphere to lock in freshness means using modified atmosphere packaging (MAP) to preserve food. This technology can be used for meat, seafood, fruits and vegetables. For example, put beef into a packaging box, then evacuate it, fill it with protective gas, and finally seal it. This gas is generally a combination of oxygen, carbon dioxide and nitrogen. Among them, carbon dioxide can inhibit bacteria that like oxygen, oxygen can inhibit bacteria that do not like oxygen, and nitrogen has no practical effect, mainly as a filling gas.

The proportion of oxygen in the modified atmosphere packaging of fresh meat is generally 60-70%, which is three times the oxygen concentration in the air, so it is also called "high oxygen controlled atmosphere".

A high-oxygen environment can promote the formation of "oxymyoglobin", making the meat color brighter. The color stratification of beef is due to limited oxygen permeability, which can only change the surface color.

This technology not only makes fresh meat look better, but also greatly extends its shelf life. It can usually be kept fresh for 12-15 days at 0-4 degrees. Currently, fresh meat in supermarkets in most European countries uses this technology. (Poultry and fish do not need red color, usually carbon dioxide and nitrogen are used)

Of course, the color of the beef exposed by netizens is a bit too red, and does not look like the color of high oxygen tone.

The bright rose red is more likely to have been treated with carbon monoxide or nitric oxide, both of which can combine with myoglobin to form a beautiful and stable red color.

However, these two gases have not yet been approved in China, and if they are used, they are used secretly. They are rarely used in meat, but mainly in aquatic products, especially red fish, such as tuna, and some white fish (red muscle on the side).

In order to find out the truth, I followed the clues and found the product page, and found a picture with a netizen's comment. When I saw this picture, I immediately understood what was going on.

First, confirm that it is a pot with modified atmosphere packaging. The darker part in the picture is where it touches the tray. Because the meat is first placed on the tray and then the atmosphere is adjusted, some parts of the bottom are not fully exposed to the gas, so the color is different.

Secondly, the color of the pictures leaked online must be wrong. It may be caused by the color difference caused by the flash, or it may be that the mobile phone camera itself has a "beautification" function. The color in the picture below is the normal high-oxygen tone color.

In fact, the modified atmosphere packaging technology has gradually become outdated, and the more advanced one is "skin packaging". Its principle is still modified atmosphere, but at the same time it is supplemented with a certain degree of vacuum and uses airtight heat-shrinkable packaging materials. It can not only maintain the color of the meat and extend the shelf life, but also make the meat more beautiful and reduce the loss of juice.

Finally, I want to remind everyone that the pictures of products on the Internet are often very beautiful, but they are just fooling you. They are usually made by color adjustment using drawing software, or by beautification pictures taken under high light conditions. (The picture below is a picture of the same type of beef sold by a merchant) When buying meat in supermarkets and farmers' markets, you also need to pay attention to whether the lighting is tampered with, and don't be deceived by your eyes.

(Internet pictures deleted if infringed)