There are many of these germs in valley water... You shouldn't soak watermelon to cool it down.

Various microorganisms inhabit the stream water.

On the surface, clear and transparent stream water is home to various microorganisms. Among them is Escherichia coli (E. coli), which tends to proliferate especially during peak vacation seasons when human waste may contaminate the water. Infection with E. coli can cause symptoms such as abdominal pain, diarrhea, and vomiting. In severe cases, it can lead to peritonitis, cystitis, or sepsis. Even a small amount of stream water can cause infection, so it is advisable to avoid drinking stream water and to refrain from immersing food items like fruits in the water before consumption.

Ulcers may develop due to parasitic infection

In river water, there are not only Escherichia coli but also parasites. The most common ones are Entamoeba histolytica and Spironucleus. Entamoeba histolytica usually has an incubation period of 2 to 4 weeks, but symptoms can rarely appear after several years. The severity of symptoms varies, but diarrhea, upper abdominal pain, fever, vomiting, and chills are common. It can cause colitis and liver abscesses. Spironucleus begins to become active inside the human body after an incubation period of about 5 weeks, moving throughout various parts of the body and destroying normal tissues. In addition to headaches, seizures, sensory disturbances, and paralysis, partial localized neurological signs may occur, and corneal ulcers can develop. Memory loss, changes in consciousness, and speech disorders may also accompany these symptoms. It can invade the eyes, spinal cord, heart, and brain, and if it penetrates the brain, it can cause a stroke.

◇ It is better to store in an airtight container rather than a lab.

Meanwhile, if leftover watermelon is covered with plastic wrap and stored, it can promote bacterial growth, so caution is needed. This is because watermelon contains a lot of moisture and sugar, and being sealed creates an environment conducive to bacteria proliferation. In fact, a study by the Korea Consumer Agency revealed that bacteria tend to grow well when watermelon is wrapped in plastic and stored. The research team used sterilized utensils such as knives and cutting boards to minimize bacterial contamination factors, and conducted experiments using a refrigerator maintained at a constant temperature of 4°C without food poisoning bacteria. However, the bacterial count on the cut surface of the watermelon stored in the refrigerator after wrapping increased by more than approximately 3,000 times compared to the initial count. The bacteria, which can cause symptoms of food poisoning such as diarrhea and stomach upset, are estimated to originate from the watermelon rind.

To store watermelon safely, ▲ wash the watermelon thoroughly before cutting, and ▲ cut it into bite-sized pieces, place them in an airtight container, and refrigerate. If it was unavoidable to wrap it with plastic wrap and store it in the refrigerator, it is recommended to cut off at least 1cm or more from the surface before consumption. When eating, wash your hands thoroughly and use utensils such as a fork.