英語聽力文摘 蜂蜜-歷史悠久的保鮮劑

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The Oldest Sweetener, the Freshest Bread

蜂蜜成分75% 以上為糖類。據(jù)市場(chǎng)調(diào)查，90% 以上的人都認(rèn)為蜂蜜與砂糖、異構(gòu)糖、飴糖、人工甜味劑相比對(duì)人體健康更為有益。蜂蜜不僅是天然甜昧劑， 而且述具有其他的特殊功效。如利用蜂蜜的風(fēng)味，甜昧、抗氧化機(jī)能和澄清天然水果汁類的機(jī)能，可以開發(fā)出多種新產(chǎn)品。

Honey has been around for a very long time. Cave paintings in Spain from over ten thousand years ago show people harvesting honey. Today honey is mostly used for its distinctive flavor, but for baking it has another advantage as well: baked goods made with honey take longer to get stale.

Honey helps baked goods stay fresh longer because, unlike common table sugar(蔗糖;食糖), honey is made of two so-called “simple” sugars: glucose(葡萄糖) and fructose(果糖). Table sugar also has glucose and fructose, but they’re chemically bonded together in a double sugar(【生物化學(xué)】雙糖) called “sucrose(蔗糖).” Having two single sugars instead of one double sugar means that ounce-for-ounce honey contains more sugar molecules, which is why honey is also a little sweeter than table sugar.

But the reason honey helps keep baked goods fresh has to do with the ability of sugar to attract and hold onto water molecules. All these sugars are “hygroscopic,” that is they attract and hold onto water, each sugar molecule holding several water molecules. By holding onto water, the sugar helps keep moisture from escaping from the food and so keeps it tasting fresher longer.

But when two sugars, like fructose and glucose, bond to each other, they lose some of their ability to bond to water molecules. And that means your bread or cake will lose water faster. Honey’s attraction to water is also why candy made from honey tends to get stickier than candy made from sucrose, or table sugar.

Commercial bakeries use chemicals like Polysorbate(聚山梨醇酯) to keep baked goods fresh, but with honey you can do it naturally. Incidentally, if you’re worried that honey will make your cake too heavy, try beating the honey until it’s frothy before adding the other ingredients.