January 2022 "Science" Rumor List: Do pre-prepared meals contain preservatives?

The list of "scientific" rumors for January 2022 is revealed! "Cold fireworks" have low temperatures, so are they safe to set off? Pre-prepared dishes are not fresh and contain preservatives? Is it more economical to refuel in the morning and evening? Let's see the truth.

The monthly "science" rumor list is guided by the Beijing Association for Science and Technology, the Beijing Municipal Cyberspace Administration, and the Capital Internet Association, and jointly released by the Beijing Science and Technology Journalists and Editors Association and the Beijing Regional Website Joint Rumor-Refuting Platform, and is supported by the Science and Technology Journalists and Editors Professional Committee of the China Science Writers Association, the China Evening News Science Editors and Journalists Association, the Shanghai Science Communication Association, and the Institute of Science and Technology Information of the Beijing Academy of Science and Technology.

1. Tonga volcano eruption will cause a "year without summer"

gossip

After the Tonga volcano erupted, a large amount of volcanic ash entered the stratosphere and was unable to settle for a long time, resulting in a "sunshade effect" and causing a "year without summer" in which the global temperature dropped.

the truth

Volcanoes do cause the Earth to "cool down", mainly because they inject sulfur-containing aerosols into the atmosphere. When these aerosols enter the stratosphere, they reflect more sunlight, thus producing a cooling effect in the atmosphere. In the past 100 years, there have been three large-scale low-latitude volcanic eruptions, namely Mount Agung in Indonesia (2019), El Chichon in Mexico (1982), and Mount Pinatubo in the Philippines (1991). In the winter of the year after their eruptions, the temperature in most parts of my country, except for Northeast China and Xinjiang, was relatively low.

But when it comes to climate impact, the scale of volcanic eruptions and gas emissions are key factors that must be considered. The Philippines' Mount Pinatubo, which caused the global average temperature to drop by 0.5°C, has a VEI of 6. Its eruption in 1991 released 20,000 kilotons of sulfur dioxide. The Tonga volcano's eruption is estimated to have a VEI of 5-6, but the sulfur dioxide released on the first day of the eruption was only 62 kilotons, which will not have a significant impact on global temperatures and will not cause a "year without summer."

A series of studies have shown that volcanic eruptions generally have a lasting impact on the global and East Asian climate in the next 1-2 years, causing a certain cooling effect. For my country, volcanic eruptions may also weaken the intensity of the East Asian summer monsoon in the following year, causing my country's summer rain belt to shift southward, affecting the rainfall during the entire flood season.

Currently, the Tonga volcano is still active and its activity needs to be further monitored. If there is no larger-scale eruption in the future, it will not affect the global temperature for the time being.

2. Refueling in the morning and evening saves money

gossip

The amount of gasoline you refuel is charged based on volume. According to the principle of thermal expansion and contraction, the same quality of gasoline has a smaller volume in the early morning and at night when the temperature is lower. Therefore, it is more cost-effective to refuel in the morning and evening.

the truth

The idea that refueling in the morning and evening saves money is not true.

Currently, gas stations all have underground oil storage depots, and they all have a certain degree of protection layer. Gasoline is stored at a constant temperature all year round and is not affected by the external temperature.

Even though the technology level in the early years did not meet the current standards and underground constant temperature oil storage could not be achieved, the density of gasoline did not change much under different temperature conditions, and the resulting price difference was very small.

3. Small wounds can be disinfected with saliva

gossip

Because saliva contains "lysozyme", you can hold your finger in your mouth when it is cut, or apply some saliva to small wounds to kill bacteria and disinfect them.

the truth

Lysozyme is an important non-specific immune factor in the body, which has the functions of antibacterial and anti-inflammatory, improving immunity, and inhibiting the growth of exogenous microorganisms. Although lysozyme is contained in saliva, it is too little to play a role in sterilization and disinfection. In addition, the secretion of saliva is affected by many factors, including age, eating habits, drug intake, living habits, etc., which vary from person to person and are not fixed.

Most importantly, applying saliva to a wound is likely to "add poison to poison." Because the oral cavity is one of the areas with the highest density and variety of microorganisms in the human body, saliva also carries various oral viruses, fungi, and bacteria. Therefore, it is recommended to use Band-Aids and iodine to treat small wounds in daily life.

4. Fresh meat suddenly jumps because of parasites

gossip

As the New Year approaches, every household begins to prepare for the New Year. However, if you find that the meat you bought is jumping spontaneously, you should be careful, as this is a sign that there are parasites in the meat.

the truth

In fact, the meat that has just been slaughtered will twitch, not because there are parasites, but because the meat is very fresh and was slaughtered very recently.

Shortly after slaughter, the central nervous system of fresh meat 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, the muscles can still beat, which is also called "super-reaction". After a period of slaughter, the ATP in the meat is exhausted, the muscle fibers will be locked, and they will not beat.

5. Artificially waxed apples are harmful to eat

gossip

If the skin of an apple is smooth and bright, feels sticky, and powder falls off when you scrape it a few times, it means it has been artificially waxed, which is poisonous!

the truth

Fruit wax is a type of food additive allowed for use worldwide. As long as it is waxed in a regular manner, it will not cause harm to human health.

In fact, during the normal growth process of apples, the skin will naturally secrete a layer of fruit wax to prevent harmful external substances from invading the flesh. This is an advantageous measure for apples to fight against the external environment and is harmless to the human body.

Artificial waxing of fruits after they are picked is an important part of the commercial processing of fruits. Its purpose is to prevent the apples from losing water and causing the skin to shrink, which leads to a reduction in freshness. It can also prevent the invasion of microorganisms to extend the shelf life.

In the production and transportation of apples, waxing is actually a regular operation. Many countries, including my country, allow waxing on the surface of fruits to preserve them. my country's "Sanitary Standards for the Use of Food Additives" stipulates that morpholine fatty acid salts (also known as fruit wax) and Brazilian palm wax can be used as coating agents on the surface of fresh fruits.

Although regular waxing is not harmful to the human body, many people may feel that it is not clean enough and want to completely remove the wax before eating apples. Experts say that the easiest way to remove the wax on the peel is to peel it. If you want to preserve more nutrients in the apple, there is a simple and easy way, which is to scald it with hot water.

6. The dose of COVID-19 vaccine for children needs to be halved

gossip

Most medications for children are used at half the adult dosage or at a reduced dosage. The dose of the COVID-19 vaccine for children also needs to be halved, otherwise the body will be "overloaded."

the truth

At present, the dosage and ingredients of the COVID-19 vaccine are exactly the same for all age groups, including children. It is a global practice to use a unified dosage while ensuring safety. The dosage of therapeutic drugs may take weight into consideration, while others may also take body surface area into consideration, which is related to factors such as drug pharmacokinetic studies and liver metabolism in the body.

However, the mechanism of action of vaccines is different from that of therapeutic drugs. After the antigens in the vaccine enter the body, they do not directly "exert their efficacy", but are presented by the immune system. After the immune cells recognize them, they produce antibodies, which then play a role in blocking viral infection or preventing disease. The above process has no correlation with body surface area or weight.

In fact, the dosage of most vaccines does not differentiate between adults and children. For example, there is no difference in dosage between hepatitis B vaccine, cervical cancer vaccine, and pneumonia vaccine. In terms of mechanism, after the vaccine enters the body of a child, the mechanism of producing antibodies is exactly the same as that of an adult, with no difference.

Immunization experts said that when getting the COVID-19 vaccine, you should pay attention to your child's health, because children over 5 years old may have some psychogenic reactions. Older children should avoid strenuous exercise and stay for 30 minutes. If the vaccinated child has any suspected adverse reactions, report it in time. If there is an overlap with other immunization vaccines or non-immunization vaccines, make sure that the COVID-19 vaccine is at least 14 days away from other vaccines.

7. Pre-prepared food is not fresh and contains preservatives

gossip

Pre-prepared dishes are not fresh and contain preservatives. Compared with fresh dishes, the most popular "pre-prepared dishes" for the New Year's Eve dinner this year are no longer fresh after being frozen and reheated. Some pre-prepared dishes have a shelf life of up to one year and must contain additives and preservatives.

the truth

Pre-prepared dishes are no different from the food we usually eat, with no additional preservatives added. The standardized and traceable production and processing process will make the taste of the dishes more stable and the quality safer.

Factory-prepared dishes are produced in a standardized manner, and consumers can restore the flavor by simply heating them on a gas stove when they take them home. The degree of flavor restoration is comparable to that of freshly cooked dishes served in the restaurant.

Most pre-prepared dishes need to be cooked at high temperatures, which is a sterilization process in itself; then liquid nitrogen and other quick-freezing technologies are used to completely inhibit the reproduction of microorganisms through ultra-low temperature freezing, so there is no need to add additional preservatives.

On the other hand, according to packaging standards, pre-prepared meals must list all the ingredients, so the ingredient list will include relevant additives in the seasonings used.

But this does not mean that pre-prepared dishes contain more additives than dine-in dishes or homemade dishes. Even the food that consumers buy and cook themselves often contains additives. For example, many soy sauces contain sodium glutamate and potassium sorbate, and some flavorings contain hydroxypropyl distarch phosphate and citric acid. As long as they meet the additive standards set by the state, the reasonable use of additives will not cause harm to the human body.

8. "Cold fireworks" have a low temperature and are not dangerous to set off

gossip

As the name suggests, "cold fireworks" have a lower ignition temperature and are not considered dangerous goods such as fireworks.

the truth

The name "cold fireworks" may be somewhat misleading. Not only are they fireworks, but their basic properties as flammable and explosive dangerous goods have not changed.

When "fairy sticks" and "electronic fireworks" are set off, the temperature of the flame (spark) drops rapidly after it is ejected, and the temperature drops to about 80°C 20cm from the nozzle, and the temperature drops to about 40°C 50cm from the nozzle, so they are commonly known as "cold fireworks". When setting off such products, the temperature at the nozzle is as high as 700-800°C, which can still burn the human body and ignite flammable materials.

Therefore, when producing, operating, storing and setting off "cold fireworks", the relevant regulations on the safety management of fireworks and firecrackers must still be strictly observed. When setting off "cold fireworks", the public should adopt the safety measures generally applicable to fireworks and firecrackers, and it is strictly forbidden to set them off indoors or in any place where setting off fireworks and firecrackers is prohibited.

9. Wearing diapers can cause "O-shaped legs" in babies

gossip

Diapers will prevent the baby’s legs from closing together, and when the child grows up, his legs will become “O-shaped”!

the truth

"O-shaped legs" have nothing to do with diapers. The fetus is curled up in the mother's belly, with its legs in an O shape. This leg shape will continue until the fetus is about 2 years old after birth, which is a normal phenomenon.

After the age of 2, as babies learn to walk and squat, their lower limbs will adjust themselves to meet physiological needs, gradually becoming an "X" shape. The "X" shape is most obvious around the age of 4-5. After the age of 6, the curvature of the "X" shape gradually decreases, and around the age of 7-8, the legs gradually develop the same appearance as adults.

The design of today's disposable diapers does not restrict the baby's leg movements. The legs can stretch naturally and move frequently to allow the joints and muscles to develop normally. Therefore, "O-shaped legs" in babies under 2 years old are a normal developmental condition and are not caused by diapers. If an abnormality does occur, it cannot be ignored. Be sure to take the baby to the hospital for diagnosis and treatment by a doctor and do not correct it yourself.

Sources of this issue: Xinhua News Agency, CCTV Finance, China Global Television Network, China News Service, China.com, Science and Technology Daily, Farmers’ Daily, Guangming Online, Economic Daily, Science Popularization China, Science Rumor Refutation, Tadpole Music, Publicity and Education Center of the Ministry of Emergency Management, Beijing Daily Client, Beijing Science and Technology Daily, Beijing News, "Rumor Filter" WeChat Official Account, Tianjin Internet Rumor Refutation Platform, "Shanghai Online Rumor Refutation" WeChat Official Account, Guokr.com, "Dingxiang Doctor" WeChat Official Account

Produced by: Science Central Kitchen

Produced by: Beijing Science and Technology News | Beijing Science and Technology Media

Welcome to share to your circle of friends

Reprinted by public accounts, newspapers, etc.

Please send an email to [email protected]

Reproduction without authorization is prohibited, and offenders will be prosecuted