A refrigerator or freezer can play a good role in preserving food and extending its shelf life. However, a refrigerator is not a magic box, and not all foods can be stored in it. So, which foods should not be put in the refrigerator? A refrigerator is so convenient—chilled watermelon, cold drinks, frozen popsicles... But it's not a safe deposit box, and not all foods are suitable for it. Nutrient loss, diminished texture, and bacterial growth are some changes that can occur even when certain foods are stored in the refrigerator.
As the weather gets hotter, many people move their food into the refrigerator to keep it safe during the summer. But did you know that the following foods are actually not suitable for refrigeration.
These foods should not be refrigerated
1. Sealed green leafy vegetables
Storing vegetables with water can easily breed bacteria, especially leafy vegetables, which have high physiological activity. If sealed too tightly and contain too much moisture, they are more likely to rot, spoil, and lose leaves.
Suggestion: First, air-dry the surface water, then place them in a special food bag and put them in the refrigerator. Before storing, poke a few air holes in the bag to ensure good air circulation.
2. Tomatoes and unripe fruits
At low temperatures, the genes in tomatoes responsible for producing aromatic compounds are like being "frozen," resulting in a significant loss of flavor.
Unripe fruits refrigerated may suffer from cold damage and remain in an unripe state. Even if moved to room temperature, they will spoil quickly.
Suggestion: Tomatoes can be stored at room temperature. After buying fruits, try to restore them to the state they were in when purchased. For example, if the fruits were cold when bought, meaning they were refrigerated, put them in the refrigerator as soon as you get home. If they were bought at room temperature, wait for them to cool down and ripen before refrigerating.
3. Leftovers and cut fruits that are not covered
Food can easily transfer flavors to each other and increase the risk of bacterial cross-contamination. Putting hot food directly into the refrigerator can cause steam to condense, promoting mold growth and leading to mold on other foods in the refrigerator.
Suggestion: Leftovers should be cooled completely, then wrapped in clean containers like保鲜盒 (fresh-keeping boxes) or保鲜袋 (fresh-keeping bags) before being put in the refrigerator. Be sure to heat them thoroughly before eating. Cut fruits should be covered with clean plastic wrap before being put in the refrigerator; you can cut off the surface layer before eating.
4. Honey
When honey is refrigerated, it accelerates the crystallization of its sugar content, leading to precipitation and making it difficult to scoop out, which also affects its taste.
However, it should be noted that this change does not affect the safety or nutritional value of the honey; it only affects the uniformity of its texture.
Suggestion: Honey has a high sugar concentration and high osmotic pressure, with very little free water, so microorganisms cannot multiply. It can be stored in a cool, dark place at room temperature and does not need refrigeration.
5. Chocolate
Putting chocolate in the refrigerator can cause sugar bloom or fat bloom on its surface, and its texture will become coarse.
When frozen or refrigerated chocolate is taken out, the condensed moisture on its surface can promote bacterial growth, possibly causing mold to form on the surface.
Suggestion: The best storage temperature for chocolate is 5°C to 18°C. It is best not to store it in the refrigerator.
6. Powdered and dried foods
If not sealed tightly, refrigerator odors and moisture can enter the food, affecting its flavor and making it easy to mold.
When taken out, the temperature difference can cause condensation on the surface, making it damp and more prone to spoilage.
Suggestion: These types of foods do not need to be refrigerated; they can be stored in a cool, dry place.
These foods must be refrigerated
1. Yogurt must be refrigerated
If yogurt is stored at room temperature, the lactic acid bacteria will die quickly (what a pity! Many supermarkets sell yogurt products at room temperature, especially the discounted ones), losing some of its health benefits and easily making the taste too sour.
2. Pasteurized milk must be refrigerated
Pasteurized milk will quickly have excessive bacteria if stored at room temperature; even in the refrigerator, it should be consumed within 48 hours. Once opened, it is best to drink it within a few hours.
3. Cooked meat products must be refrigerated
Cooked meat products may breed bacteria, including various dangerous pathogens. Bean products are even more susceptible to massive microbial growth than meat products. It is best to store them in the deep part of the refrigerator near the inner wall or in a fresh-keeping box.
4. These foods need to be refrigerated for long-term storage
Additionally, some items do not need to be refrigerated if they will be consumed within a short time, but if you intend to store them for a long time, they also need to be refrigerated.
5. Dried seafood products like shrimp
For example, dried seafood products like shrimp are very likely to absorb moisture at room temperature and deteriorate in quality (some products already have insufficient moisture content). This not only produces a pungent ammonia smell from protein breakdown but also generates carcinogenic nitrosamines.
6. Sauces and condiments
For example, various sauces and condiments can be temporarily stored at room temperature, but they will slowly undergo fat oxidation and flavor changes. If you really can't finish them within two weeks, it's safer to store them in the refrigerator. Less salty condiments like salad dressing and ketchup must be refrigerated after opening.
Theoretically, if we ignore safety and resource conservation issues, and only consider product quality, most foods actually have better preservation effects when stored in the cold for a long time. For example, some people say that storing sealed tea leaves in the refrigerator can reduce the loss of aroma. Another example is that storing household oils, peanut butter, and sesame paste in the refrigerator allows them to be stored longer without oxidizing. Even spices like curry powder and five-spice powder will have better quality after a few months in a low-temperature environment than at room temperature. For meat canned goods, storing them in the refrigerator for a year results in less loss of B vitamins than storing them at room temperature.
Most products are better preserved at 0-1°C than at 4-6°C, such as most vegetables and fruits from northern regions. However, considering energy consumption, only refrigerated meat is usually stored between -1°C and 1°C.