It is reported to cause hepatitis A in many parts of the United States and Canada. When people mention strawberries, they shy away. Dr. Jiang can't help but wonder why strawberries are so delicious. The combination of these factors has invisibly turned strawberries into a vector

Strawberry actually overturned again

It is said that it has caused hepatitis A in many places in the United States and Canada

and has caused many deaths

When people mention strawberries, they shy away

Strawberries sold in stores have also been removed from the shelves

Picture source: FDA official website screenshot

Dr .Jiang can’t help but wonder, strawberries are so delicious

Why are they always the ones that get into trouble

Is it really “dirty” or is it really unfair

Strawberries are not the only “dirty fruits”

Strawberries have always been complained about as the dirtiest fruit. , is also the fruit with the most black material recently. There are two main reasons why strawberries "bring black constitution". First of all, strawberries are different from other fruits in that they have a "coat" for protection. The pulp is "exposed" and can easily be contaminated by various viruses. Secondly, the surface of strawberries is uneven and the pulp is "brittle", making it extremely difficult to clean. The combination of these factors has invisibly turned strawberries into a vector for spreading viruses. The "hemorrhagic fever" incident that caused a heated discussion last year was caused by mice crawling over strawberries and becoming infected with the virus. From this point alone, It’s true that strawberries are “dirty”!

Click let me try

In fact, strawberries are not "alone" when it comes to "dirty". Most berry fruits, such as bayberry, mulberry , cranberry and other fruits, can also be combined with It "debuts in a group".

The reason is that these fruits have several common characteristics: no skin wrapping, uneven surface, fragile and easily damaged. Because of these characteristics, this type of fruit can easily harbor dirt and evil. The grooves and seams on the surface are the favorite places for various insect eggs to "reside". Without the outer skin as a barrier, the fruit pulp can also be easily contaminated by bacteria. On the other hand, cleaning is difficult. Just rinsing with water may not completely clean it. Rubbing it hard may damage the pulp. Therefore, these fruits can easily be considered "dirty fruits".

In addition, some people think strawberries are dirty because of their pesticide residues. For this reason, strawberries have been elected as the "dirtiest fruit" champion for three consecutive years.

Do you think fruits with skin on are not dirty?

Compared with "dirty fruits" such as strawberries, bayberries and mulberries, fruits such as apples and pears are much cleaner in the public opinion, because they have natural skins that act as a strong barrier against "dirty things", and when washed, You don’t have to worry about damaging the pulp, you can still peel it and eat it. But this does not mean that fruits with skins are safe and pollution-free. In the list of "dirtiest fruits", grapes, cherries, pears and apples have been named!

This is because these fruits are easily cross-contaminated with knives when cutting, and pathogenic bacteria will "grow well" on the damaged parts or cutting surfaces of the fruits. Therefore, fruits that are easily damaged or squeezed are also susceptible to pathogenic bacteria. Infect. All in all, as long as there is an invasion of microorganisms, the fruit will not be able to escape completely!

There are five major categories of common microorganisms that contaminate fruits, namely Salmonella , Escherichia coli , Listeria , Shigella and Staphylococcus aureus . Most of these bacteria belong to the food-borne pathogenic bacteria . They are ubiquitous in daily life. Many of them are common bacteria that exist in the human body, such as E. coli and Staphylococcus aureus. They themselves are not harmful to the human body. , but after multiplying in large quantities in food, it can easily produce toxins, which can also cause diseases after human infection. In some cases, symptoms of infection can be very severe, especially infants, children, the elderly, and people with weakened immune systems (such as cancer patients) who are at higher risk of developing severe disease, which can be life-threatening in severe cases [1].

Therefore, no matter what kind of fruit it is, regardless of whether it has skin or not, there is a possibility of being contaminated and dirty. Proper cleaning, storage and cutting is the only way to keep fruit "clean".

What is the right way to clean fruits?

When it comes to cleaning fruits correctly, some people may find it dismissive. Who doesn’t know how to wash fruits? But in fact, some people really don’t know how to wash fruits! In the traditional concept of many people, you can eat fruits after you buy them and rinse them with water. Some people even think that if they are not clean, you will not get sick if you eat them. This is indeed true for the era when pesticides were not used in the past. Can. But for fruits that have grown up under the "care" of a large amount of pesticides, just washing them with water is not enough. Moreover, clean water does not have the sterilization effect.

In addition, many people believe that fruits washed with salt water will be cleaner. Salt water is indeed helpful in removing insect pests in fruits and vegetables. For example, salt water can soak out some insect eggs in fruits and vegetables such as cherries, bayberries, and mulberries. . However, some people either soak for too long or add a lot of salt. The concentration is too high, which will damage the cell membrane of the fruit. Not only will nutrients be lost, but pesticide residues may also enter the fruit.

In addition, some people like to cut the fruit first and then soak it. For example, fruits like pineapples may also be contaminated with bacteria in their peels. Cutting and soaking directly will allow some bacteria to penetrate into the fruits and vegetables, causing secondary pollution, and also making the in the fruits and vegetables water-soluble. Vitamin is missing. Moreover, after the fruit is chopped, the direct contact area with water increases, the chance of contamination increases, and the loss of nutrients is also greater.

So, how to clean fruits correctly?

Berries and grapes should be washed before eating.

Berries such as strawberries, bayberries, blueberries, , etc. are quite fragile and can easily rot when exposed to water. If they are exposed to water and then placed in a humid environment, they will easily rot. It is affected by mold, so it is recommended to wash it before eating. Of course, there are also things to pay attention to when cleaning.

When cleaning fruits such as strawberries, bayberries, mulberries, or cherries, the salt water soaking method can indeed eliminate pesticide residues and help sterilize them. However, it should be noted that strawberry fruits must not be soaked for a long time, because there will be a small amount of pesticide residues on the surface of such fruits, and the main component of pesticide residues is organophosphorus , which is insoluble in water. Soaking does not work, and long-term soaking may even cause secondary pollution. In addition, if the concentration of soaking salt water is too high, it is easy to form osmotic pressure , which will cause pesticide residues to enter the inside of the fruit [2].

Generally speaking, when fruits are soaked and cleaned in salt water, as the soaking time increases, the amount of pesticide residues in fruits and vegetables will first decrease and then increase, reaching the lowest in about 10 minutes. Therefore, the soaking time is generally 10 minutes. . It is better to use warm water than cold water when soaking. Just rinse it with running water after soaking.

When washing blueberries or grapes, you can add 2 tablespoons of wheat flour, flour or tapioca flour. Pour in an appropriate amount of water, which will turn milky white. Soak the grapes or blueberries for two minutes. Then gently scrub, and finally run through clean water, which can basically remove the dust and fruit wax attached to the grapes or blueberries.

Fruits with skin should be washed even if they are peeled.

As mentioned before, even fruits with skin can be easily "targeted" by some food-borne pathogenic bacteria, especially those with hard skin or rough mesh skin. When the fruit is cut, bacteria may be transferred to the pulp, which is conducive to the growth of microorganisms and contaminates the fruit. Therefore, before peeling or slicing, you should also scrub the hard skin of the fruit, or use a special brush for cleaning fruits to scrub thoroughly under running water before cutting.

In addition, many people buy hard-shelled fruits such as longans, lychees, and mangosteens and eat them directly without washing them. However, in fact, when picking these fruits, the pickers may spray them. sulfur dioxide and other chemicals to extend the shelf life. Sulfur dioxide has low toxicity and is soluble in water. Therefore, before eating such fruits, it is best to rinse the branches with running water, which can effectively remove most of the sulfur dioxide.

Is the fruit and vegetable cleaning machine an IQ tax or is it really useful?

In addition to the traditional method of cleaning fruits, the fruit and vegetable cleaning machine that has been crazily "flyed" by major Internet bloggers in the past two years has also taken advantage of the trend to become popular on the Internet. Does the fruit and vegetable cleaning machine really have such an obvious effect? Can vegetables and fruits washed with a fruit and vegetable washing machine really be eaten raw with their skins on?

There are various types of fruit and vegetable cleaning machines on the market, and the prices range from hundreds to thousands. In terms of working principles, there are ultrasonic, ozone , active water-based, hydroxy water ion, etc. But no matter which one they are, the main function of such products is to remove pesticides, hormone residues, harmful bacteria, waxes, heavy metals and other substances harmful to the human body on the surface of fruits and vegetables.

Data shows that the ultrasonic cleaning machine has a power of 1000 watt hours and can clean pesticide residues in 15 minutes, but the skin of fruits and vegetables will be damaged. As for ozone cleaning machines, in addition to sterilization, ozone can also form a chemical reaction with pesticides to clean pesticide residues. Of course, this takes a certain amount of time. Generally, the pesticide residue degradation rate is about 50% in 30 minutes, but its effect is not as good as ultrasonic. is good. At the same time, the escape of ozone will also affect human health, so this type of machine has been gradually phased out.

Most of the current mainstream fruit and vegetable cleaning machines use hydroxyl water ions, which use to electrolyze water to form OH- and H+ for sterilization. For example, OH- can destroy the structure of pesticides and bacteria, causing them to lose their activity. There is also a chemical reaction between OH- and chloride ions to form HCLO, which plays a sterilizing effect. However, it is worth mentioning that the sterilization effect of this type of fruit and vegetable cleaning machine also depends on the power of the machine.

Hydroxy water ion fruit and vegetable cleaning machine After cleaning the fruits for 30 minutes Staphylococcus aureus sterilization rate
5W	0W	5W
9.48%	4.82%	9.94%

The results show that the greater the power of the fruit and vegetable cleaning machine

the more significant the sterilization effect [ 3]

In addition, the length of time the cleaning machine is used also determines the effect. Fruits and vegetables such as strawberries are easy to clean with pesticides, but fruits and vegetables with deeper attachments such as apples and peaches have a somewhat unsatisfactory cleaning effect. Therefore, whether the fruit and vegetable cleaning machine is useful or not depends entirely on its working principle, power and cleaning time. If you understand these issues, you might consider buying one to experience it.

Safe and effective

Cost-effective fruit and vegetable cleaning agent

In fact, regarding how to deal with pesticide residues and microorganisms on fruits, in addition to the fruit and vegetable cleaning machine, there is also a product that is relatively safe and effective, and at the same time very cost-effective, that is, the fruit and vegetable cleaning agent .Some people may worry that fruit and vegetable cleaning agents will contain chemicals. Although pesticide residues are removed, other chemical components will be left behind, causing secondary pollution of the fruits.

In short, strawberries, the "dirty fruit" that has been popularly searched for, are actually not as "dirty" as everyone says. The main problem is that the sterilization of the fruit is not done properly. Any kind of fruit, as long as it is properly cleaned And the work of sterilization and disinfection is actually not dirty!