Don't worry. Here's a step-by-step guide on how to clean your fridge.

"Listeria in the fridge" has suddenly become a target for many pregnant women to defend against.

Someone posted a note saying that a pregnant woman they knew had a miscarriage after eating unheated food from the fridge, which has further raised concerns.

Netizens have been sharing their tips on avoiding Listeria in the fridge: Seal fruits before putting them in the fridge; Store fruits in a separate drawer; Buy a small fridge specifically for fruits; Only eat apples, oranges, and bananas that need to be peeled, and avoid directly eating blueberries and strawberries; Don't eat fruits at all.

In fact, there's no need for us to be overly cautious about the "branches" of Listeria transmission. A more direct and proper approach is to eliminate Listeria from the "root" in the fridge and then enjoy the food in it with peace of mind.

So, what should we do? Clean the fridge!

1. 2,400 times dirtier than a toilet

The fridge is dirty!

Last year, a study in a domestic city showed that among the 15 sampled household fridges, the average total number of bacteria in the refrigerating compartment was 2.9×104 CFU/cm2 (CFU is the abbreviation of "colony-forming unit", representing the number of bacteria capable of reproduction)[1].

It's actually a blessing that most people have no idea about this number, but now I'm going to take that blessing away.

This number is 5,800 times the hygienic requirement for cups and utensils (such as dinner plates) in public places according to China's national standards, and even 2,400 times the requirement for sanitary ware (such as toilets) in public places.

It's shocking! How could the fridge in our home, which stores food, be dirtier than a public toilet that meets hygienic standards?

(Whisper 1: Although it's very likely that public toilets don't meet the standards.)

(Whisper 2: But I never thought there would be so many bacteria in the fridge.)

There are three reasons for the large number of bacteria in the fridge.

Firstly, the fridge doesn't create bacteria. The bacteria must be brought in from the outside.

The drinks we buy from the supermarket, the vegetables from the market, and the eggs we just took out of the chicken coop yesterday all carry various bacteria into the fridge. This is the inevitable source of bacteria in the fridge.

Secondly, bacteria won't be killed in the fridge.

The temperature in the refrigerating compartment of a fridge is generally around 4 degrees Celsius. This temperature is not enough to kill bacteria; it just presses the "pause" or "slow" button on their reproduction. Once you open the fridge door and the temperature inside rises, they'll seize the opportunity to feast and reproduce several generations of offspring.

Lastly, bacteria can find nutrients in the fridge.

Crumbs of biscuits, soup, juice oozing from rotten fruits, leftovers, and water vapor in the fridge... are all a feast for bacteria. They won't starve to death in there (except when the fridge only stores bottled and canned drinks).

Let me give you a more intuitive shock.

I inoculated the bacteria on my finger onto a culture medium, put it in the fridge's refrigerating compartment for seven days, and when I took it out, there were visible colonies. At room temperature, it would take only one day for this many bacteria to grow.

This shows that in a low-temperature environment with nutrients, the fridge can indeed slow down the growth of bacteria for a while, but it can't do so indefinitely.

2. What will happen if you don't clean the fridge?

Firstly, it'll stink!

Many people notice a "fridge smell" in their fridges. Part of this smell comes from food, like onions, ginger, and garlic, and another part comes from the "farts" of bacteria.

If you open the fridge and are greeted by a putrid smell (methyl mercaptan), the smell of rotten eggs (hydrogen sulfide), or other non - food odors, you should know that the invisible bacteria in the fridge have multiplied to a level that requires attention.

More seriously, it's about food safety.

Bacteria are everywhere in our living environment. Among the bacteria that tend to multiply in the fridge, there are coliforms, Salmonella, and the Listeria mentioned at the beginning. These are pathogenic bacteria, and they come into direct contact with food!

Coliforms - They have the highest detection rate. By themselves, they're not extremely dangerous, but an over - standard amount often means a high possibility that the food has been contaminated by other bacteria.

Salmonella - A healthy young adult might just have a bout of diarrhea, but for young children, the elderly, and the sick, an infection can have serious consequences.

Listeria - It can cause infections in the lungs, brain, blood, etc. Pregnant women infected with it may have a miscarriage or stillbirth.

Some people will surely say, "My elders haven't cleaned the fridge for decades, and nothing has happened!"

This kind of thinking is wrong!

Cleaning the fridge is like brushing your teeth. Brushing your teeth every day doesn't guarantee good health, but not brushing will surely lead to tooth decay sooner or later. Moreover, nowadays, cleaning the fridge isn't a particularly troublesome thing. It's worth cleaning regularly for the sake of your quality of life and health.

3. An effective and not - too - troublesome guide to cleaning the fridge

When cleaning the fridge, we should aim at two targets.

Target 1: The bacteria's supply chain 

Remove the visible food residues, vegetable and soup juices, accumulated water, and dust so that bacteria can't grow fat and strong.

For this part of the cleaning, it's highly recommended to use disposable kitchen wipes with cleaning agents. They're clean, soft, and can effectively kill bacteria.

 It's not recommended to use ordinary rags (which may introduce a large number of bacteria into the fridge) or steel wool (the fine scratches it makes are like building nests for bacteria).

Also, it's not recommended to use cleaning agents like 84 disinfectant or toilet cleaner. Although there may be more bacteria in the fridge than in a toilet, these bathroom cleaning agents can affect the quality of food or leave a smell that reminds you of the toilet.

This kind of cleaning is recommended to be done as soon as you see dirt. At the very least, do it once a week.

Target 2: Invisible microorganisms

 Currently, the mainstream method for fridge sterilization is using ozone. Ozone is a gas that can reach every nook and cranny of the fridge. It has a wide sterilization range and good effects.

The ozone sterilizers specially designed for household fridges are very small and can continuously release ozone to sterilize without being too obtrusive.

 Disadvantages: It can't penetrate sealed packages like plastic wraps and storage boxes; it can oxidize high - fat foods and make them taste rancid, and it can also oxidize the rubber materials in the fridge and make them age; if the concentration is too low, it won't work, and if it's too high, it can irritate the respiratory tract, so it has high requirements for the product itself.

You can also choose ultraviolet sterilization. As an "ancient" sterilization method, the effectiveness of ultraviolet rays has long been verified. It's a pure physical sterilization method, so there's no residue problem.

Disadvantages: Ultraviolet rays are light and travel in a straight line. If they're blocked by fridge partitions, food, or bottles, there will be sterilization dead - ends. You need to empty the fridge before using it.

Both of these small appliances are not expensive.

If your fridge has a built - in sterilization function, you don't need to make a choice.

After cleaning the visible garbage and stains, just follow the instructions. Sterilization doesn't need to be done too frequently.

Once every one or two months or a quarter is enough. You can increase the frequency appropriately in the hot and humid summer.

Note! After cleaning the inside of the fridge, don't forget to clean the handle and the sealing strip!

Finally, the above content only applies to the refrigerating compartment of the fridge.

As for the freezing compartment, as long as it hasn't thawed during storage and the food is fully heated after being taken out, there are generally no food safety issues.

However, the longer the food is frozen, the worse the flavor will be, and there will also be a loss of nutrients.

Also, when you eat the ribs that have been frozen for 10 years, you'll probably feel sad about the electricity bills spent on storing them over the past 10 years.