It’s better not to eat this kind of melon!

Summer is the time when a lot of fruits are on the market. Among all the fruits, watermelon is definitely the best fruit to beat the heat. So, as a veteran watermelon eater, how much do you know about the preservation of watermelon? Is the refrigerator's freezer a "safe" for watermelons?

Written by reporter Li Jing Edited by Chen Yongjie

New Media Editor/Wang Jiayi (Intern)

Interview experts:

Chen Chunxiu (Researcher, Beijing Academy of Agricultural and Forestry Sciences)

In fact, watermelon is not a fruit that is suitable for long-term storage, especially if it has been cut. It is best to eat it as soon as it is cut. If the watermelon is too big and you can only eat half of it, the other half should also be covered with clean plastic wrap and placed in the refrigerator. Of course, even if it is refrigerated like this, it is best to eat it as soon as possible within one day.

"If watermelon is left for too long, even if it is still edible, its quality will deteriorate, the flesh will become soft, and the taste will be very different," explained Chen Chunxiu, a researcher at the Beijing Academy of Agricultural and Forestry Sciences who has been engaged in the research and promotion of new watermelon varieties and cultivation techniques for many years.

How does the quality of watermelon change? The study "Study on the Quality Changes and Storage Characteristics of Different Varieties of Watermelon during Room Temperature Storage" used "Jingxin No. 2" and "Jingxiu" watermelons as research objects. Through the analysis of temperature and humidity, weight loss rate, water content and other data, it was found that as the storage time increases, the watermelon rind will continue to become thinner and the quality loss will increase. The study also pointed out that during this process, the main nutrients such as glucose and fructose contained in the watermelon are constantly consumed, but the water content and other changes are relatively small.

(Photo source: Visual China)

The above study discussed the changes in the quality of uncut watermelons as they are stored for a longer period of time. Under normal circumstances, the interior of uncut fresh watermelons is basically sterile. Once a watermelon is cut, it is more likely to become seriously spoiled due to the presence of bacteria and microorganisms.

Due to its high sugar content and abundant water content, watermelon is very popular with various bacteria. Moreover, the number and type of bacteria are related to the storage environment, temperature and time. If there are more bacteria in the storage environment, the temperature is higher and the storage time is longer, the number and type of bacteria in watermelon will increase, which will lead to a decline in the quality of watermelon.

It can be said that when cutting watermelons, people have already begun to "destroy" the quality of watermelons. Chen Chunxiu gave an example, saying that the flesh of a melon with knife scratches will appear "water-soaked", and the color will be darker red than the normal flesh. The quality of this part of the "injured" flesh will decline faster. As time goes by, the sugar in the flesh will be converted into starch granules, the sweetness will decrease, and it will gradually rot, and then appear in the state of "loes". She suggested that in order to better extend the "shelf life" of watermelons, people should clean knives, cutting boards and other items that come into contact with watermelons before cutting watermelons, and wrap the watermelons that are not eaten temporarily with clean plastic wrap, and then place them in the refrigerator to reduce the impact of bacteria and other factors on the quality of watermelons. In general, the preservation of watermelons is related to environmental factors such as temperature and humidity, as well as human factors such as whether they are cut. A complete watermelon can be stored in a cold storage at 7-10 degrees Celsius for two weeks to one month, and can be kept for about seven days at the natural temperature in early summer, but the quality of the watermelon will decline with the extension of time. Once a watermelon is cut, its quality will decline faster and its taste will gradually deteriorate due to various irresistible environmental factors. If you find that the color and smell of the watermelon have changed significantly, it is recommended that you put your health first and don't eat such watermelon.