Introduction: Recently, media reports have revealed through experiments that covering watermelon with plastic wrap and then refrigerating it actually leads to more bacteria than when it's not covered. Experts explain that the plastic wrap hinders the watermelon from cooling down, creating conditions for bacterial growth. "If the bacteria are highly virulent, even a small number can cause illness."
Netizens were shocked, exclaiming, "I've been using it for so many years, could I have been wrong all along?"
However, the claim was soon questioned by many food safety experts, who pointed out numerous flaws in the experiment. "Can the experiment guarantee that the plastic wrap, knife, and cutting board used on the watermelon were not contaminated?" asked a university professor. "Personally, I think the experiment is of little significance because, in real life, it's certainly not advisable to leave food in the refrigerator without covering it with plastic wrap."
Impermeable, Faster Bacterial Reproduction
Jinshi Dong, a food safety expert and Executive Vice President and Secretary-General of the International Association of Food Packaging, believes that watermelon wrapped in plastic spoil faster than unwrapped watermelon. This is because before the watermelon is covered, its surface already has bacteria and microorganisms. If the plastic wrap is not breathable or permeable to water, the temperature drops slowly, causing these microorganisms or bacteria to reproduce faster, especially after anaerobic reactions occur, which can easily lead to food spoilage.
It is reported that if the plastic wrap is too thick, it prevents the food from "breathing" oxygen, leading to anaerobic fermentation and subsequent spoilage. It should be noted that some people think that wrapping it in multiple layers is better for preservation, but plastic wrap not only needs to retain moisture but also allow carbon dioxide to escape; a wrap that is too thick is actually不利于保鲜.
Certain Fruits Are Not Suitable for Plastic Wrap
Experts remind that not all foods need to be stored with plastic wrap. This is especially true for fruits and vegetables that naturally release ripening gases, such as tomatoes and bananas. Using plastic wrap on them can hinder the release of the ripening gas ethylene, thereby shortening their shelf life.
The best way to preserve food is to consume it in the shortest possible time. Airtight containers can retain moisture while preserving the food's flavor, so for storing cooked food, a better choice is to use an airtight container.