奇速英语

古埃及蜂蜜沉睡千年仍可食用？

It is common for food products in supermarkets today to carry a date that tells you when they are no longer fresh. However, one natural product can last for hundreds, or even thousands of years, under the right conditions — honey. Archaeologists have found pots of honey in ancient Egyptian tombs that were perfectly safe to eat. Although it seems unbelievable, this is due to a special chemical balance found in no other food.

Firstly, natural honey has very little water. Bees collect a sweet liquid from flowers and then beat their wings to dry it out. In such a dry environment, bacteria and other tiny living things cannot survive; they simply die. Honey is also naturally acidic; its pH is between 3 and 4.5, which kills most living things that try to grow on it. What’s more, honey produces hydrogen peroxide (过氧化物), a powerful bacteria-killing substance. This comes from a chemical reaction inside the bee’s stomach. Bees have an enzyme (酶) called glucose oxidase (GOx). When they bring the sweet liquid back up from their stomachs to make honey, this enzyme mixes with it and breaks it down into gluconic (葡萄糖的) acid and hydrogen peroxide.

Thanks to these germ-killing qualities, honey has been used in medicine for thousands of years. Sumerian clay tablets from around 2100–2000 BCE record its use for treating burns and cuts. The ancient Egyptians also used honey as a medicine often, preparing healing creams for skin and eye diseases. Meanwhile, they held honeybees in high regard, as they believed the insects originated from the tears of the sun god Re.

However, these chemical wonders do not work on their own. The most important step is to keep honey in a sealed container. Supermarket honey is heated and filtered to remove impurities (杂质), so it stays smooth, while more traditional, less-processed honey may crystallize. But as long as it is sealed, it will stay good. So always close your honey jar tightly — who knows? Thousands of years from now, it might become an archaeological treasure dug up by future civilizations.