Preserving 25 years of noncorrosive hamburger "longevity" does not necessarily require preservatives.

Original title: Keeping 25 years of non-perishable burgers "longevity" doesn't necessarily require preservatives
Recently, two men in Australia claimed that the McDonald's "4-ounce beef fort" they bought in 1995 was still stored in boxes made by them, with no signs of decay.
, McDonald's closed three stores in Iceland during the 2009 financial crisis, and a customer rushed to buy the last burger and French fries at the last minute to keep a memorial. Ten years on, the customer's burger is still intact.
two news, so that "McDonald's burgers are not rotten" in the hot search list, but also a lot of people concerned about nutrition and health concerns: Why hamburgers can not mold for 25 years, because preservatives are strong? Can I enjoy the burger with peace of mind in the future?
this, science and technology daily reporters to the relevant experts to prove that "Hamburg is not corrupt" mystery.
microbes are the main culprits of food mold
to know why food does not rot, first of all to understand, food mold is caused by the problem?
, deputy director of the clinical nutrition department at Qinghai Provincial People's Hospital, told Science and Technology Daily that mold is a common natural phenomenon that occurs mostly in food.
any food, it will go bad after a period of time at room temperature - some moldy lumps, some rotting and smelling, some acidic. The main reasons for food quality are: First, the environment is ubiquitous microorganisms, food in the production, processing, transportation, storage, marketing process, it is easy to be contaminated by microorganisms. As long as the water is adequate and the temperature is appropriate, microorganisms will grow and reproduce, breaking down nutrients in food to meet their own needs. The protein in the food is destroyed, the food smells and sour, loses its original toughness and elasticity, and the color changes. Second, animal food (animal-sourced food) has a variety of enzymes, under the role of enzymes, food nutrients will be broken down into a variety of low-level products. Meal hair, fruit decay, is carbohydrate is broken down by enzymes and fermented. Third, grease is easily oxidized, producing a series of chemical reactions, oxidized grease has a strange taste.
no preservatives can make hamburgers so
long life
in order to delay and inhibit food mold, humans invented preservatives.
Xiongrui said that in order for food to have a certain shelf life, it is necessary to adopt appropriate measures to prevent microbial infection and reproduction. Preservatives are a kind of food additives that can inhibit microbial activity and prevent food corruption and metabolism, which has a continuous inhibitory effect on the growth of microorganisms with metabolic substrates as corrupt substances.
" preservatives, there are roughly the following three kinds. One is to interfere with the enzyme system of microorganisms, destroy their normal metabolism, inhibit the activity of enzymes. The second is to make the protein of microorganism solidify and denature, interfere with its survival and reproduction. The third is to change the permeability of the plasma membrane, inhibit the elimination of enzymes and metabolites in the body, resulting in ineration. Xiong Rui said.
preservatives prescribed for use in China are benzoic acid, sodium benzoate, sorbate, potassium sorbate, calcium acrylic and other 30 kinds. However, the effect of preservatives is not absolute, only for certain foods have a certain limit of the role of extending the storage period, and its anti-corrosion effect will vary according to environmental pH changes. In addition, preservatives must be used according to the added standards and must not be abused arbitrarily.
in McDonald's burgers, cheeses and Big Macs, there are preservatives and additives such as benzoic acid, sebum, sunset yellow and jaundice. So, the burger has been mouldy for 25 years, is it really because the preservatives in it are strong enough?
Zhu Yi, an associate professor at the School of Food Science and Nutritional Engineering at The Agricultural University of China, told Science and Technology Daily: "Preservatives, as the name suggests, are prevention rather than treatment, in other words, they are used to protect food when the amount of bacteria in the food belt is very small, not when the amount of bacteria in the food is very high." Under
use of the same amount of preservatives, the more serious the food contamination, the more primitive bacteria, the worse the anti-corrosion effect. For example, when food has been seriously contaminated by microorganisms, sorbic acid not only can not do anything about microbial reproduction, but will become a nutrient of microorganisms, accelerating food corruption.
She says that under normal circumstances, even with preservatives, a hamburger can't be stored for a decade or two, unless vacuum, ultra-low temperatures and other ways of combining preservation, and fast food is not intended to be preserved for a long time, there is no need to add a lot of preservatives to it.
it takes days, land, people and
how exactly does a burger that's not rotten be made? Experts point out that it will take time, land, people and people to get such an "old hamburger".
first, the meatloaf in the middle of the burger belongs to fried food, and the fried meat pie is partially dehydrated by a non-enzyme browning reaction, said Mr. Xiong. Second, under certain climatic conditions, hamburgers may dry out before they decay, and the water activity in food is lower than the minimum need for microbial growth, making it impossible for bacteria and mold to grow. After that, as long as it is free from the tide, it can be kept for a long time without being bad.
"The mold-free 'old burger' coincides with the 'day when the air is dry', the 'land' where the storage environment is clean, and the 'people and' who are not eaten, making it difficult for bacteria and mold to settle on it, so it can remain sterile for years without the help of preservatives. Of course, after a long period of time hamburgers, just look good, vegetables have been broken down and disappeared, flavor taste is greatly reduced, can be left as a souvenir, but not to eat the stomach, because it is no longer suitable to eat, the taste is not good. Zhu Yi said.
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They can last long without preservatives
In fact, there are many diets that can be preserved for a long time, even without adding preservatives, such as liquor, honey, soy sauce, etc.
liquor
is one of the most common wines in China, known as "old wine" said. Pure grain brewed liquor, in the suitable temperature, humidity, dryness and other environment to do sealing preservation, as long as not open, or even save a hundred years is not a problem. This is mainly because the alcohol level of liquor is generally relatively high, and alcohol itself has the role of sterilization, disinfection, under the influence of alcohol, the microorganisms in liquor is difficult to survive, which makes liquor will not appear corrupt, bad situation.
soy sauce
soy sauce is generally kept for two years without adding preservatives. This is not only because the brewing soy sauce in the process of strict high temperature sterilization, sterile filling and other processes, strictly control the corruption, the phenomenon of the survival and reproduction of microorganisms. Also because the raw materials for brewing soy sauce are generally soybeans, wheat and other food crops, these food crops under the role of fermentation bacteria will produce a variety of amino acids, and then metabolize phenylalanic acid, benzoic acid and benzoic acid and other substances, these substances themselves have the role of inhibiting microbial reproduction, growth.
Honey
Honey is also a typical kind of food that can be preserved for a long time without adding preservatives, honey because of its high sugar properties, making it difficult for microorganisms to survive and reproduce, so it can be preserved for a long time without adding preservatives. However, it is worth noting that if the honey packaging is opened, it needs to be eaten within a certain period of time, because after opening the packaging, there may be cross-infection of food, and when microorganisms, moisture, etc. into the honey, will lead to honey fermentation, quality.
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