Apples should be refrigerated to ensure both quality and health
Core Tip: The suitable storage period for apples at room temperature is within 15 days, while the suitable storage period for refrigerated apples is within 30 days. If you buy a large quantity at once and cannot finish them in a short period, it is best to refrigerate them.
Apples are best stored in the refrigerator
Apples are rich in nutrients such as sugars, organic acids, cellulose, vitamins, minerals, polyphenols, and flavonoids, earning them the title of "all-around healthy fruit" by scientists. However, after being picked, apples are prone to aging and rotting due to their own respiration and metabolism, water loss, and microbial contamination, which leads to a decline in fruit quality and nutrient content. To study the relationship between apple storage conditions, storage time, and nutritional content, we conducted a follow-up monitoring.
A batch of Fuji apples purchased from a fruit store was divided into two groups and stored separately in a refrigerator (4°C) and at room temperature (average 18°C). We observed the apples' appearance over 60 days and measured their weight loss rate, reducing sugar, titratable acidity, vitamin C content, and nitrite content to compare the differences under the two storage temperatures.
Apples stored at room temperature showed significant changes in nutritional content between 7 and 15 days. By day 15, the peel was wrinkled and the texture became soft. By day 30, brown spots appeared on the flesh. The weight loss rate increased significantly after 7 days, and by day 15, the vitamin C loss reached 50%, with a notable increase in nitrite content. In contrast, the refrigerated apples did not show significant changes until day 30. For example, the texture only began to soften on day 30, and the peel became wrinkled on day 60, with a vitamin C loss of 30%.
Furthermore, over the same storage period, the weight loss rate, increase in nitrite content, and decrease in vitamin C content of apples stored under refrigeration were significantly lower than those of apples stored at room temperature. This may be because at room temperature, the apple's respiration consumes its own water and nutrients, and the appearance of rot increases nitrite levels. In contrast, during refrigerated storage, the apple's respiration rate slows down, ethylene release is reduced, and therefore, the consumption of its own nutrients and water is less than at room temperature, and rotting also occurs later.
The suitable storage period for apples at room temperature is within 15 days, while the suitable storage period for refrigerated apples is within 30 days. If you buy a large quantity at once and cannot finish them in a short period, it is best to refrigerate them.