How can we eat cold chain food safely? What should we pay attention to when traveling during the Spring Festival?

Recently, the media broke the news that ice cream and imported cherries were tested positive for the new coronavirus nucleic acid, causing panic among the people and the cold chain became a hot topic among citizens.

Cold chain foods frequently have problems. Is it worthy of trust? As an ordinary consumer, how can we properly prevent and control them and how can we safely eat frozen and fresh foods? Today, the editor will talk to you about the knowledge of the cold chain.

Source | Sina Weibo People's Daily

1

What is the cold chain?

The cold chain is a process in which fresh, perishable and difficult to preserve products are kept in a low-temperature environment at all stages before consumption to ensure product quality. It is a special supply chain with high technological content.

The fresh agricultural products we often buy, such as meat, poultry, eggs, seafood, and some processed foods, such as quick-frozen dumplings, frozen meatballs, ice cream, etc., all need the protection of the cold chain. In addition, the cold chain can also be used to transport medicines, vaccines and other products.

These products require different temperatures. If they are not properly transported and stored, it will easily affect the product quality and cause the product to deteriorate.

Source: Promotional page of a certain brand of cold chain vehicle

The cold chain involves many links, mainly including the production site - pre-cooling station - logistics center - retailer, and finally reaches the hands of consumers. Traditional normal temperature logistics does not have the pre-cooling link. The main function of the pre-cooling station is to cool the product.

Taking fruits and vegetables as an example, the surface temperature of freshly picked fruits and vegetables is high, and they carry a lot of field heat. The fruits also have vigorous respiration and generate energy. If they are not pre-cooled in time, the fruits will mature quickly and easily rot.

Through pre-cooling treatment, the respiration and water evaporation of fruits and vegetables can be effectively controlled to prevent the loss and reduction of nutrients. At the same time, the low temperature environment can inhibit the growth and reproduction of bacteria to achieve the purpose of preservation.

Source: Pexels

2

Why has the cold chain become a virus “gathering place”?
It is common knowledge to use cold chain to preserve fresh food and prevent bacterial growth. So why is the cold chain ineffective in the face of the new coronavirus?

The most suitable survival temperature for common bacteria is between 20°C and 35°C. Most of them find it difficult to proliferate or survive normally at low temperatures, while the opposite is true for viruses.

Viruses are composed of nucleic acid molecules and an outer protein shell. Coronaviruses like the new coronavirus also have an envelope on the outside.

Before a virus finds a host, it is just a fragile "particle" without any signs of life. Lower temperatures are conducive to maintaining the stability and integrity of its structure, which is more conducive to the survival of the virus. The humidity in the freezing environment is higher, so the refrigerated and frozen environment provides good living conditions for the new coronavirus and becomes a "sanctuary" for the virus.

In fact, in addition to the cold chain, as the temperature drops, conventional logistics may also become a channel for virus transmission.

Wu Zunyou said that after entering winter, all international freight environments are similar to what we call the cold chain in summer, so the low temperature in winter causes the "non-cold chain" to tend towards a "cold chain" effect.

Therefore, both "cold chain goods" and "non-cold chain goods" must be strictly managed according to standards, and product sampling and testing and regular personnel screening must be implemented.

Source: Promotional page of a certain brand of cold chain vehicle

In addition to the viruses we are afraid of, are there other risks in the cold chain?

In fact, if the storage and transportation of the cold chain are not handled properly, it will also cause some food safety problems.

Moreover, the cold chain is a low-temperature system project that requires very high equipment and technical content. For example, for frozen meat storage, the temperature is generally required to be maintained at around -18°C and the humidity is best maintained at 90% to 95%. If the corresponding requirements are not met, such as temperature fluctuations, meat products will easily deteriorate.

Therefore, the corresponding refrigeration equipment and cold chain transport vehicles also need to meet the qualification standards. If they are not strictly supervised and easily put into use, it is easy for food quality problems to occur.

Source: Pexels

3

Can we still eat cold chain food safely?
Although cold chain problems frequently occur in epidemic prevention and control, do we really have to deny cold chain technology because of the new coronavirus?

Earlier, at a press conference held by the State Council’s Joint Prevention and Control Mechanism, the relevant person in charge stated that the customs found 6 samples containing the new coronavirus among 227,934 cold chain monitoring samples, including 5 inner and outer packaging samples, 1 environmental sample, and 0 product samples.

According to the information released at a press conference of the State Council’s Joint Prevention and Control Mechanism in November last year, the national random inspection positive rate for imported cold chain foods was 0.048%, and was mainly concentrated on the outer packaging of food.

In other words, the product was contaminated during processing and packaging, and the new coronavirus was not generated in the cold chain. In addition, my country has a large demand for fresh food, and imported products can make up for the shortage of domestic supply. It is impossible to directly ban the import of all frozen foods.

In addition, relevant departments have very strict control over imported cold chain foods. Currently, imported cold chain foods are not allowed to be put on the market without a nucleic acid test report.

On the other hand, there is no definitive evidence that the novel coronavirus can be transmitted through the digestive tract. A positive nucleic acid test result for cold chain food does not mean that it is contagious.

Therefore, imported fruits and cold chain foods purchased from regular channels are basically safe to eat. However, in addition to strengthening the supervision of cold chain food companies, which is the "main line of prevention and control", as individuals, we should also handle and eat cold chain foods correctly. In this regard, the Beijing Center for Disease Control and Prevention has given relevant guidance.

Source: Pexels

I have kindly compiled some notes for you:

When shopping : Go to regular supermarkets or markets to buy fresh products, avoid direct contact with your hands. Wear gloves when shopping, and store them separately from other products. Pay attention to food label information such as product production date, shelf life, and storage conditions.

During cleaning and processing : keep raw and cooked food separate. Containers, knives, cutting boards and other utensils used to handle frozen and chilled foods should be placed separately. They should be cleaned and disinfected in a timely manner to avoid cross contamination.

When cooking and eating : Seafood should be cooked thoroughly and kept for 10-15 minutes after boiling. Try to avoid eating seafood raw, half-cooked, soaked in wine, vinegar or salted. For raw fruits, rinse them thoroughly with running water and extend the rinsing time appropriately. You can also use a special fruit and vegetable cleaner to wash them.

In addition, after you bring the frozen fresh food you bought home, you can first disinfect its outer packaging with 75% alcohol. In addition, after processing the frozen food, disinfect the items that have been in contact with it to make dining more secure.

For everyone, not going home

January 28 is the first day of the Spring Festival travel rush

This year's Spring Festival is destined to be different from previous years

Some people stand in the snow to ensure smooth travel

Someone is on call 24 hours a day to keep the lights on in every home

Some people also transformed into "Dabai" and raced against time

There are millions of you and me

Take love as home and celebrate the New Year in place

…

The 2021 Spring Festival travel season has officially begun. What should you pay attention to during this year's Spring Festival travel season due to the epidemic? How can you protect yourself during your trip? Follow this picture to learn more about it.

Choose to stick to

Just for a better gathering

Wherever you are

Being together is reunion

Waiting for the flowers to bloom and the epidemic to dissipate

Let’s go home together!

Review expert: Wang Guoyi, Postdoctoral Fellow in Nutrition and Food Safety, China Agricultural University

Source: Digital Beijing Science Center, CCTV News, People's Daily Online