Most foods stay fresh longer when stored in a refrigerator maintained at about 3 to 4 degrees Celsius. However, some foods can produce toxins or spoil more easily when refrigerated. Learn which foods to be cautious of.

◇Garlic, mold, and other toxins can form

Storing garlic in the refrigerator can lead to the development of toxins such as mold. When garlic is refrigerated, it absorbs moisture from the fridge, making it soft and easy for sprouts and mold to proliferate. Peeled garlic is more susceptible to mold than whole garlic cloves. This is due to phenolic compounds contained in the garlic skin. Phenolic compounds have a sterilizing effect, preventing the growth of mold spores and acting as natural antioxidants. Additionally, garlic becomes inherently more vulnerable to mold once the skin is removed, as the tissue is damaged during peeling.

Damaged garlic with broken tissues experiences a shortened shelf life due to microbial damage such as weight loss, aroma loss, surface discoloration, and mold. Therefore, garlic should be stored at room temperature in a cool, dry, and dark place rather than in the refrigerator without peeling. Peeling garlic damages the tissue and exposes the surface, promoting microbial growth and creating an environment more conducive to mold than unpeeled garlic. However, peeled garlic, unlike whole garlic, should be stored in an airtight container with a paper towel to block moisture, and kept refrigerated at 0-4°C.

◇Tomatoes lose moisture and their sweetness decreases

Storing tomatoes in the refrigerator halts their ripening process, causes their surface to become wrinkled, and reduces their sweetness. The cold air in the refrigerator also leads to moisture loss, which is problematic. Additionally, the vitamin C content decreases. A research team from Pukyong National University’s Department of Food Engineering stored tomatoes at 10°C, 20°C, room temperature (25°C), and 30°C for five days, then measured their vitamin C content. As a result, higher temperatures led to increased vitamin C levels. It is better to store tomatoes at room temperature between 25°C and 30°C, away from sunlight, rather than in the refrigerator. Care should be taken not to exceed 30°C or expose the tomatoes to strong sunlight, as this can destroy nutrients.

◇Mayonnaise, prone to spoilage due to ingredient separation

Mayonnaise is easily spoiled if stored at low temperatures.

Mayonnaise is made by mixing egg yolks, vinegar, cooking oil, salt, and other ingredients, but these components can separate if stored at low temperatures. They should be stored at around 10 to 30 degrees Celsius to prevent separation of the ingredients. Therefore, it is best to keep it in a cool room temperature away from sunlight. However, after opening and coming into contact with air once, it is advisable to store it in the refrigerator. Since placing it deep inside a cold refrigerator can cause the oil layer to separate, it is more appropriate to keep it on the shelf near the refrigerator door, where the temperature is relatively higher.