What is the difference between "best before date" and "use-by date"?
Whether food that is about to expire can be eaten depends first on clarifying this "date". One is called the "best before date", also known as the "best before period", which is known as the "shelf life" abroad. It refers to the period during which the food maintains its quality under the storage conditions specified on the label. Under proper storage conditions, food past its best before date may still be edible for a certain time if its color, aroma, and taste have not changed. The other is called the "use-by date", which is the final date by which the product should be consumed. He Jiguo points out that after the use-by date, the food may undergo quality changes, no longer possess the quality characteristics desired by consumers, and should not be eaten, let alone sold.
Storage conditions are very important
"The best before date is only a relative concept," experts say. Under normal circumstances, food will not spoil within its best before date, but if the storage environment does not meet the requirements, the food's taste, smell, and appearance can change very quickly, which may cause the best before date to become invalid prematurely. Below, we will explain this using several common food items.
Dairy products: Dairy products are very perishable. If left at room temperature, they can spoil within a few hours. For discounted yogurt in the supermarket that is nearing its expiration date, if you know you cannot finish it within that time, don't buy it.
Cooking oil: The shelf life of cooking oil is usually 18 months, but this is on the premise that the package is unopened. The fatty acids in cooking oil undergo chemical changes over time, and its nutritional value decreases accordingly. Therefore, it is very important to check the production date when buying oil; the fresher, the better. Once opened and exposed to air, the shelf life of cooking oil will be shortened accordingly. Even if not finished, it should be replaced at least every three months.
Rice and flour: The shelf life of rice and flour varies from 6 to 12 months at room temperature. In northern regions, if stored in a place that is not hot and humid, and under normal conditions, it can be extended to 24 months. However, once rice or flour becomes moldy, it must not be eaten.
Bread and pastries: The shelf life varies by season, generally 7 days in winter, 3-5 days in spring and autumn, and 1-2 days in summer. However, if bread is not stored properly, it can often grow mold the very next day. In this case, even if it hasn't expired, it must be thrown away decisively.
Eggs: They do not have a fixed shelf life. It is generally fine to consume them within 3-5 weeks of purchase. Usually, the quality of eggs drops one grade every week, but they are still edible.
The refrigerator is not a safe
Storing food at room temperature is not scientific because the optimal temperature range for many microorganisms is 4°C to 60°C. For perishable foods, they should be refrigerated immediately after bringing them home. If you do not plan to eat them right away, they should be frozen immediately. You must remember that your home refrigerator is not a factory's quick-freezing production line; most can only "slow freeze". During the slow-freezing process, the food's nutrients and flavor will change, and the texture and quality during cooking will also significantly decrease. After putting food in the refrigerator, eat it as soon as possible.