Grandma Wang, who is 73 years old this year, has a slight inconvenience in her legs and feet, and lives in an ancient community without elevators, so she is always happy to stay at home and avoid running outside.
Therefore, she habitually hoarded a large amount of vegetables and meat in the refrigerator to reduce the trouble of going back and forth, however, over time, the meat and vegetables in the refrigerator were piled up, and various ingredients were mixed together, which seemed quite messy.
On this day, her grandson, who had not met for a long time, brought her girlfriend to visit Grandma Wang, which made her feel particularly happy, and in order to express her joy, Grandma Wang decided to cook a hearty meal herself.
So, she turned out the pork that had been hoarded in the refrigerator for months, and this piece of meat had been repeatedly thawed and refrozen, which looked a little unfresh.
However, Grandma Wang did not realize this, and she cooked this piece of meat as usual and made it into a delicious dish.
However, soon after the meal, the grandson, girlfriend and grandma Wang all developed vomiting, diarrhea and other uncomfortable symptoms, and they rushed to the hospital, where they were diagnosed by doctors as suffering from acute gastroenteritis.
After some drip treatment, the three began to improve. Doctors pointed out that acute gastroenteritis is mostly caused by eating unclean food.
At this time, Grandma Wang woke up like a dream and thought of the frozen meat that she had hoarded in the refrigerator for a long time. She felt remorse and felt deep remorse for not managing her ingredients and paying attention to food safety.
The fridge is not a safe and food storage is limited
We must understand that the refrigerator is not equivalent to a safe, although the refrigerator has the role of keeping food fresh, but it can not permanently preserve food, in the process of opening and closing the door of the refrigerator, temperature fluctuations will also have an impact on the freshness of food.
Take meat as an example, during the purchase process, meat is susceptible to bacterial contamination; In the process of taking it home and storing it in the refrigerator, the fat and protein in the meat will oxidize, producing fat oxidizing substances, resulting in nutrient loss and poor taste.
Have you ever heard of "zombie meat"?
In the past, zombie meat refers to frozen meat that has been frozen for many years and then reached the market, and most of this meat is smuggled goods, and its quality and safety cannot be guaranteed.
However, more and more household refrigerators now store meat that has been frozen for a long time, which can also be called zombie meat.
Li Xingmin, a meat expert and associate professor at the College of Food Science and Nutritional Engineering of China Agricultural University, said: Different types of meat are frozen and stored for different times, and generally speaking, meat frozen in household refrigerators for more than half a year is not recommended to continue to be eaten.
Can eating frozen meat for a long time cause cancer?
In this special period, people always like to store a lot of meat in the refrigerator, however, sometimes this meat is forgotten in the freezer, and over time, they become so-called "zombie meat".
In order to verify whether these "zombie meats" may have health effects, Shandong TV's "Life Survey" program conducted a detailed investigation.
To illustrate the problem, we might as well think of these four samples as four different states:
Sample No. 1, pork frozen for about a year,
Sample No. 2, frozen fish for about two years,
Sample No. 3 and Sample No. 4 are fresh and frozen pork and fish, respectively
Next, we bring these four protagonists to the stage of professional institutions, through sophisticated instruments to detect their volatile salt base nitrogen content, according to the national food standards, the limit of volatile salt base nitrogen for meat products is ≤15mg/100g, and the limit for salt-based nitrogen for marine fish is ≤30mg/100g.
During this testing process, we must not only focus on the VOA-based nitrogen content of each sample, but also understand the health effects behind them.
In this test, we also carefully study the specific situation of each sample, combined with the relevant standards, to reach a scientific and accurate conclusion.
Finally, through a series of experiments and analyses, the "Life Survey" came to an interesting conclusion: Sample No. 1 and Sample No. 2, that is, those pork and fish that have been frozen for too long, their volatile salt-based nitrogen content exceeds the national standard limit, which indicates that these "zombie meats" may pose a potential threat to people's health.
Therefore, we should try to avoid eating meat that is refrigerated or frozen for a long time to protect our health, and in this conclusion, we see the power and wisdom of science.
It teaches us that "zombie meat" is not just a cold piece of meat, but a factor that can pose a threat to our health.
Through this survey, we have a deeper understanding of the importance of food safety, which is the important message that the "Life Survey" program hopes to convey to the audience.
Through this story, we understand a truth: whether it is food or anything else, we need to understand and treat it with a scientific and rational attitude, and only by deeply understanding and correctly dealing with various problems can we ensure that our lives are healthier and safer.
After testing, the volatile salt-based nitrogen of fresh pork and pork frozen for about one year was 7.81mg/100g and 11.7mg/100g, respectively, and the volatile salt-based nitrogen of fresh fish and fish frozen for about two years was 10.6mg/100g and 23.0mg/100g, respectively.
Although the meat that has been frozen for a long time is significantly higher than that of fresh meat, the values are in line with national standards, and there is no risk of exceeding the standard or food poisoning.
As Mao Ziqi, an expert in agricultural food testing technology from SGS, said, salt-based nitrogen mainly reflects the freshness of meat or aquatic products.
If the salt base nitrogen content exceeds the standard, it means that meat or aquatic products may have spoiled. If consumed in large quantities, there may be a risk of food poisoning.
Although eating frozen meat does not necessarily cause cancer, it may face several consequences:
What harm will long-term use of frozen meat cause to the human body?
Causes food poisoning
When the frozen meat is thawed, the temperature rises and the destroyed tissue cells will ooze a large amount of protein and water, which is like providing a fertile soil for bacteria, so that the meat becomes a paradise for bacteria.
These bacteria will gradually decompose the protein and fat in the meat, producing a large number of harmful small molecule material decomposition products, such as small molecule amines produced by protein decomposition, aldehydes, ketones, peroxides, etc. produced by fat oxidation. If people consume such meat, they may experience food poisoning symptoms such as vomiting, nausea, and diarrhea, threatening their health.
Accelerates aging
Although freezing can curb the growth of bacteria and prevent food spoilage, it cannot completely stop the oxidation process of fat and protein.
Once the meat is oxidized, the long-term oxidation will gradually make the color of the meat dark red, and the fat of the fat meat will also begin to yellow.
At the same time, freezing can not completely lock the delicious taste of the meat, but will make it gradually produce a fishy smell, once the oxidized meat is accidentally eaten, the fat oxidation products in it will accelerate the aging process of the human body.
Decreased immunity
In frozen meat, hidden microorganisms, bacteria and parasites still quietly live, multiplying toxins and gradually penetrating the meat.
When the meat is thawed, these microorganisms seem to wake up from hibernation, becoming more active, so that the process of meat corruption and deterioration is greatly accelerated, and long-term consumption of this meat will undoubtedly reduce the body's immunity and bury a time bomb for health.
It is best not to freeze fresh meat for more than 1 month
The shelf life of meat at a low temperature of -18 ° C can be as long as 10-12 months, however, due to differences in meat handling and freezing conditions, there are significant differences in the shelf life of frozen meat.
Therefore, in order to ensure the quality and taste of fresh meat, it is recommended to control the frozen storage time of fresh meat within 1 month and up to 3 months.
It is worth noting that the freezing effect of household refrigerators is poor compared with professional cold storage, and frozen meat will still gradually deteriorate when stored in household refrigerators for a long time, so it is recommended that everyone best eat the frozen meat bought home within a week to maintain its freshness and quality.
Extension: 3 ways to teach you to eat "fresh" frozen meat
We all know that fresh meat is always the most delicious, but in some special cases we may need to stock some frozen meat, but don't worry, here are three ways to help you keep frozen meat fresh and healthy.
First of all, about thawing. One day in advance, remove the ingredients you need to thaw from the freezer, put them in crispers, and place them in the refrigerator for thawing. This is a very practical tip to keep your meat in its original taste and nutrients during the thawing process.
Next is pickling. After thawing, slice or shred the meat, first add a little salt and cooking wine to enhance the umami of the meat, then add egg white and starch, stir well so that the gravy is tightly locked. This curing process can make the meat more tender and taste better.
The last method is stir-frying. When you sauté the meat until it turns white, you can remove the meat and control the oil. When the dish is eight years old, put the meat back in the pan and stir-fry it a few times. In this way, the meat quality after cooking will be more tender and delicious.
As for everyone's concerns about the safety of frozen meat, in fact, the mainland's fresh cold chain has been very advanced, and most of these products have been scientifically stored and segmented, and tested to qualify.
So, after buying it home from the supermarket, as long as we can put it in the refrigerator in time to freeze, we don't have to worry too much. Let's enjoy the food together while ensuring good health!