Can expired food be eaten?
Introduction: Food safety has always been a concern for the public. We often see promotional activities where many foods nearing their expiration dates are sold at a discount. There have even been cases where "the shelf life is actually set by the manufacturer itself." So, can expired food still be eaten?
What does "food spoilage" mean?
Every food has multiple attributes, such as appearance, color, texture, taste, safety, and more. When we say a food is "qualified," it means it meets our standards in all these aspects. In other words, it meets the manufacturer's promise to the consumer in every respect.
In modern society, it's difficult for food to be "made and eaten immediately," especially processed foods. From production to consumption, they must go through transportation, distribution, and other stages. Therefore, preserving food is unavoidable. During preservation, all the attributes mentioned above change at a certain rate. The attribute that changes fastest varies among different foods. For example, in fresh foods like milk, eggs, and meat, bacterial growth usually occurs first, followed by changes in odor and other aspects. For biscuits, it's usually moisture absorption that makes them soft, with texture being the first to change. For instant noodles, the oil may oxidize first, producing a strange smell. Bacterial growth and oil oxidation produce harmful substances, while food becoming moist and soft just makes it less tasty. In the food industry, all of these are considered "food spoilage."
The "shelf life" generally refers to the period during which no aspect of the food has undergone significant changes. In other words, this is the manufacturer's commitment that within this period, the food's flavor, texture, and safety will all be guaranteed. If a problem occurs, the manufacturer is responsible. After the shelf life expires, it doesn't mean the food is spoiled; it just means the manufacturer no longer guarantees its quality. Sometimes, an expired food may just be less appealing in appearance or not as tasty... such food can still be eaten. However, the problem is that it could also be that the number of pathogenic bacteria has increased, raising the likelihood of getting sick after eating it. Moreover, you cannot determine what kind of changes it has undergone.
So, the answer to the question "Can expired food be eaten?" is: eating it doesn't necessarily lead to problems, but the probability of problems increases.
Obviously, food spoilage is a continuous and gradual process. The food's components or the bacteria within them don't change according to our instructions based on the shelf life—they won't, as many people might think, behave properly before the expiration date and suddenly turn into poison after it. This process of change is also influenced by production processes and storage conditions. For example, pasteurized milk, when refrigerated, generally won't have excessive bacteria growth for two weeks; while ultra-high temperature sterilized milk can be stored at room temperature for months or even years without bacterial growth. Even for the same type of food, such as pasteurized milk, different manufacturers' process control conditions can lead to different rates of change.
Therefore, for the same food, a manufacturer with better technology can achieve a longer shelf life, which is very common and normal. China's national unified shelf life for many foods is actually not reasonable—foods with poor production control can spoil even within the nationally permitted shelf life. In this case, a food that meets the national "shelf life standard" could very well be spoiled. For manufacturers who invest in improving their production processes to extend the shelf life, the national standard, on the contrary, dampens their enthusiasm. As for whether manufacturers would fraudulently label shelf lives, what is needed is monitoring to see if the food is still合格 within its shelf life. Those that are not合格 should be heavily penalized, and those that cause harm to consumers need to compensate. Under strict supervision, no manufacturer would dare to mislabel.
It should be noted that "not spoiling within the shelf life" requires following the manufacturer's storage instructions. Otherwise, the food may spoil within the shelf life, and the manufacturer is not responsible. For example, the two-week shelf life of fresh milk assumes it is unopened and refrigerated. If it has been opened or left at room temperature, it can spoil quickly, and the manufacturer is not responsible. Another example is biscuits; if unopened within the shelf life, they can remain crispy. But if the bag is opened and the environment is humid, they will quickly become moist and soft, making them unpalatable. In such cases, the manufacturer cannot be held responsible either.
Whether it's the "shelf life" or the "expiration date," it's just a control standard. For foods with a relatively long shelf life (e.g., several weeks or even months), there is little difference between the day before and the day after the expiration date. It's like how in China, men can get married at 22, but a person won't have any physiological difference the day before or after their 22nd birthday.