Recently, large-capacity refrigerators and freezers have unexpectedly sold well, and on the network platform, there are many "popular science" of vegetables that teach how to use refrigerators to keep fresh. So, how to keep the freshest vegetables in the refrigerator? The reporter learned from the Jiangsu Academy of Agricultural Sciences that the agricultural product preservation technology and equipment innovation team of the Agricultural Facilities and Equipment Research Institute of the academy, together with the agricultural science popularization innovation team, had randomly purchased 20 kinds of vegetables and carried out scientific classification, using experiments to tell everyone how to "keep fresh" vegetables in the refrigerator more scientific.
Mandatory Group :
Leafy green vegetables, young stem vegetables (asparagus, toon, etc.), flower vegetables (broccoli, cauliflower, etc.), edible mushrooms (except grass mushrooms)...
Experts remind: Li Pengxia, deputy director of the Institute of Agricultural Facilities and Equipment of the Provincial Academy of Agricultural Sciences and head of the agricultural product preservation technology and equipment innovation team, told reporters: These vegetables should still pay attention to in the preservation process: First, please put on the preservation bag and put them in the refrigerator; second, it is best not to clean before storage, because the high humidity environment formed after dipping in water will accelerate the deterioration of vegetables. Third, even if there is a refrigerator "protective body", but these vegetables are relatively delicate, water and vitamins are easy to lose, the placement time should not be too long, about 3 days is appropriate.
Do not put the group for a long time:
Eggplant, cucumbers, peppers, beans, pumpkins, sweet potatoes...
Experts remind that these are not suitable for long-term storage in the refrigerator, because they are "cold and sensitive vegetables", "just like the girls in the south can't stand the cold in the north, they are very sensitive to low temperatures", the temperature of ordinary refrigerators is 0 ~ 4 ° C, such a low temperature environment will greatly reduce its quality and appearance, this phenomenon is called "cold damage". Li Pengxia said that bananas in the refrigerator will turn black when they are taken out, also because of cold damage. Cold damage phenomenon is more obvious in tropical fruits such as bananas and mangoes, so tropical fruits are generally not suitable for the refrigerator.
The suitable storage temperature of these vegetables is: cucumber, eggplant: 8-10 ° C; green pepper: 7-9 ° C; pumpkin: 10-15 ° C or more; sweet potato 10-14 ° C. It should be reminded that it is also recommended to use a plastic bag to put it in the refrigerator without putting it in the refrigerator, and it can be put into the refrigerator for a short time in the summer high temperature weather!
The laboratory simulates cold damage to eggplant and cucumber, and there is no problem on the surface
"Healthy" cucumbers are compared to "cold-damaged" cucumbers, do you see the difference?
Here, to specifically take the tomato out to say: tomato is a special existence, the green ripening stage of the tomato is suitable for storage above 10 ° C, at this time forced into the refrigerator, it may not be ripe. Mature tomatoes are suitable for storage temperature of 3 ~ 8 ° C, can be refrigerated in the refrigerator at 4 ° C for a short time, but the time should not be too long, otherwise it will lose its umami taste and produce frost damage and rot.
Tomatoes that are "cold damaged", cut and contrasted
Can be placed or not put group:
Onions, potatoes, turnips...
These are all storage-resistant vegetables, which can be placed at room temperature for a short time, and can also be placed in the refrigerator when there is enough space in the refrigerator at home. The long-term storage temperature of potatoes is 1 ~ 3 ° C, and the highest should not exceed 5 ° C, otherwise it is easy to germinate.
A few questions:
1 How to keep dishes fresh for a long time when you put them in the refrigerator?
Unlike meat, fruits and vegetables are harvested and remain a living organism that continues to undergo a series of physiological and biochemical changes. "It is breathing like us, and for fruits and vegetables that leave the soil to supply nutrients, each breath is at the cost of consuming energy and nutrients in its own body, so that the weight of fruits and vegetables is reduced, gradually aging, and eventually dying." Researcher Li Pengxia said that here, it needs to be emphasized that we recommend that you eat all vegetables as soon as possible, after all, fresh is the best. Leafy greens should not exceed 3 days, and other vegetables are best eaten within 1 week.
If the naked eye can see the vegetables shrugging their hair, then it is time to throw it away! If you are really reluctant to eat, then in fact, you will basically eat a fiber, and you should not force nutrition.
If there is a moldy spot, there is nothing to discuss, please do not hesitate to throw it away! Don't think about digging up moldy parts and eating them, because at this point, in the microscopic world that you can't see, the fungal toxins produced by mold may have spread to other parts of the vegetable.
In order to prevent cross-contamination and skewering, never let vegetables "run naked". Use a plastic bag or plastic wrap for the dish. "The emphasis here is on 'plastic bags', not supermarket plastic bags, because only plastic bags are considered for breathability and moisture permeability and freshness when developing."
Families with conditions can add a layer of non-woven paper or paper towels to the vegetables and other paper with good water absorption to prevent "condensation" and extend the shelf life of vegetables. Avoid squeezing and place flat in the freezer, avoiding the inner wall of the refrigerator to prevent frostbite.
2 Why is the plastic bag wrapped well, and some dishes still go bad?
Experts say that in fact, this is still related to the breathing of vegetables. Different types and varieties of vegetables have different breathing intensities, some love "big panting", some are born with "lung capacity" is small, some like more oxygen, some like more carbon dioxide... Therefore, a single type of household plastic bag is not omnipotent, and sometimes long-term unreasonable use will aggravate the loss of vegetables.
Li Pengxia said that just like in winter, when we fog up against the glass, there will be a phenomenon of "condensation" in the storage process of vegetables. If there is a serious water droplet falling or odor, it may be caused by the mismatch between the packaging material and the respiratory characteristics of the vegetable.
Although the water droplets are small, the lethality is very large, and for vegetables, it may be an extremely deadly drop. When these small dewdrops touch the surface of vegetable wounds, it will accelerate the growth and reproduction of pathogenic bacteria, and vegetables will rot and deteriorate in a short period of time.
The reporter learned that the agricultural product preservation technology and equipment innovation team of the Agricultural Facilities and Equipment Research Institute of jiangsu Academy of Agricultural Sciences is centering on the "big problem of small fruits and vegetables", making sufficient "embroidery efforts" for the respiratory characteristics of different fruits and vegetables, developing fruit and vegetable packaging materials suitable for different respiratory characteristics, and introducing anti-fog, bacteriostatic, antioxidant and other functions, so that vegetable monarchs can enter the people's vegetable baskets with a more "full vitality" and "full spirit".
Agricultural Product Preservation Technology and Equipment Innovation Team, Institute of Agricultural Facilities and Equipment, Jiangsu Academy of Agricultural Sciences
Yangtze Evening News/Purple Cow News reporter Yu Dandan
The experimental pictures were provided by the Agricultural Science Innovation Team of the Provincial Academy of Agricultural Sciences
Proofread by Faye Wong