Professor Fan Zhihong from the College of Food Science and Nutritional Engineering, China Agricultural University, offers detailed guidance on the safety and knowledge surrounding food nearing its expiration date.

According to Fan, there's no universally agreed-upon definition of "nearing expiration." However, some guidelines offer a reference point. For foods with a shelf life of over a year, "nearing expiration" starts 45 days before the expiration date. For foods with a shelf life of 6 months to under a year, it's 20 days; 90 days to under 6 months is 15 days; 30 to under 90 days is 10 days; 16 to 30 days is 5 days; and for items under 15 days, it's just one to 4 days.

Some items with short expiration dates also have short "near expiration" periods. Photo: Aboluowang

Some items with short expiration dates also have short "near expiration" periods. Photo: Aboluowang

Within their expiration dates, packaged foods are entirely safe to consume if stored correctly. Laws in some countries require supermarkets and stores to categorize and label food nearing its expiration date separately, and not sell it alongside fresh items without informing consumers.

To recoup costs, many retailers offer steep discounts or set up separate displays for these items, even creating entire store chains specializing in "near-expiration" goods.

"Buying food nearing its expiration date doesn't equate to unhealthy habits. The key is to be selective," Fan said.

Consumers should buy from reputable supermarkets and stores, keeping three points in mind. First, buy only what you need; don't overbuy just because of low prices, especially for processed foods high in oil, salt, and sugar.

Second, pay attention to the production date, as oil-rich products like nuts can become rancid if not vacuum-sealed.

Third, choose smaller packages over larger ones for quicker consumption. If you're not eating the item immediately, store it in the refrigerator.

Canned goods can still be used past their expiration date if the packaging is unopened. Photo: Aboluowang

Canned goods can still be used past their expiration date if the packaging is unopened. Photo: Aboluowang

Besides "near-expiration" items, some expired foods are still usable if the packaging is intact, undamaged, and free of unusual odors. Canned goods are a prime example, as they're sterilized at high temperatures and are unlikely to spoil if unopened.

Low-moisture items like crackers, cereals, and nutrition bars can also last a long time because bacteria and mold have difficulty growing in dry environments. Some pasteurized and hot-sealed fruit juices and bottled teas remain safe at room temperature if unopened.

However, "unspoiled" only means free from microbial contamination, not necessarily retaining full nutritional value. Even within their expiration date, products can spoil if the packaging is torn, exposed to moisture, inadequately sterilized, or improperly refrigerated. Therefore, carefully examine the color, smell, and texture before consuming any food to ensure safety.

Bao Nhien (According to Aboluowang)