Author/Wang Silu (national secondary public nutritionist, internal auditor of HACCP food system of the People's Republic of China)
Rumors: If the ice cream is further frozen after melting, a large number of listeria will be produced, which will lead to "food poisoning" in the human body after consumption.
truth: The process of "melting freezing" of ice cream is totally a change in physical properties and will not produce new substances. Repeated freezing and thawing of ice-cream products, as long as they are stored regularly, will not lead to a large number of "listeria" and food poisoning.
Ice cream itself is made of water, milk, eggs, sugar, grease and other substances. In addition, some emulsifiers, essences and other additives are added. It is a kind of frozen food with expanded volume after mixing, sterilization, homogenization, cooling, aging, freezing and other processes.
The statement that "ice cream will produce pathogenic substances after being frozen after melting" is not reliable.
First of all, the ice cream in the process of "melting freezing" is completely a change in physical properties, and there will be no "chemical" change at all, so it will not produce new substances in itself.
Secondly, the ice cream has undergone strict "sterilization" treatment in the overall production process. It will not lead to a large number of "listeria" reproduction and food poisoning.
Finally, Listeria is indeed a microorganism that can grow and reproduce under low temperature environment. In addition, it mainly infects through food and gastrointestinal tract. After infection with Listeria, it is indeed easy to cause meningitis, endocarditis and other diseases.
However, "Listeria monocytogenes" is afraid of "high temperature". Generally, it is difficult to survive at a high temperature higher than 70 ℃. Ice cream packaging will undergo strict high-temperature sterilization treatment before use, and the temperature has exceeded 70 ℃.
Therefore, in view of the problem of "Listeria monocytogenes", we recommend that you buy products that are "produced by regular manufacturers, sold in large supermarkets, and stored under reliable conditions". The substandard and unreliable ice cream is also prone to be contaminated by Listeria monocytogenes due to improper operation or inadequate sterilization (human factors) during processing.
For the ice-cream products repeatedly frozen and thawed, as long as they are stored regularly, there is no major problem, but they will affect the taste and food sensory properties. It is recommended to "eat less".
Who doesn't recommend ice-cream?
1、 Caries and obese people
For caries and obese people, "sugar" is undoubtedly a kind of "fear" material, while ice cream often contains more sugar and calories, and regular consumption will undoubtedly increase the risk. Therefore, for caries and obese people, it is best not to eat, and eating must also be limited.
2、 Three high population
Ice cream, high in sugar, fat and calories, is a "dangerous food" for the "three high people", so it is recommended to eat less.
3、 Some people who need special care
Pregnant women, lying in women, middle-aged and elderly people, teenagers, etc., have special physical conditions and need careful care; Ice cream, an unhealthy food, should be deliberately avoided or eaten less.
How to "eat" ice cream to be healthier?
1、 Select products produced by "regular manufacturers"
Relatively speaking, the ice-cream produced by regular manufacturers will be more reliable. For example, for the sealing and sterilization of packaging, the safety is relatively high, which will reduce the safety risks affecting health.
2、 Identify labels and choose products with higher "nutrition level"
Identify the ingredient content from the nutrition ingredient list and ingredient list, and try to buy products with higher milk content (there will be signs in the ingredient list). If the words "vegetable cream, hydrogenated vegetable oil, trans fatty acid" appear in the ingredient list, please refuse to buy.
In addition, the fewer additives, the more natural they are. Please choose carefully.
3、 It's OK to eat, please "limit"
Too much ice cream can easily lead to stress reaction, diarrhea, abdominal pain and other acute gastroenteritis symptoms. In addition, it can also damage the health of teeth, so it must be "limited".
For "independently packaged" ice-cream, it is recommended to eat no more than one ice-cream every day, and try to choose small packaged ice-cream products. For special groups (three high population, dental caries, gout and other groups), the dosage should be reduced.
4、 It is recommended to eat in "two meals" to reduce injury
Eating ice cream before meals will affect normal appetite, reduce the intake of dinner food, destroy the diet structure, dilute gastric juice, and even affect the gastrointestinal digestion function, which is not conducive to the absorption of nutrients; Eating after meals will increase the digestive burden of the gastrointestinal tract. Therefore, it is recommended to "eat between meals".
5、 Take your time. Don't worry
Although ice-cream is delicious, it should not be "gobbled". Swallowing it will increase the stimulation of internal organs and blood vessels, make them contract violently, lead to local anemia, and even affect the digestion and sterilization ability of gastrointestinal tract, and induce inflammation. ■ (Source: WeChat official account of "Science Popularization China")
