時(shí)差N小時(shí):如何保存肉類(lèi)?(上)

On the way home from the grocery, you get delayedso much that the frozen meat you’ve bought thawsout. The question for this Moment of Science isshould you refreeze it? We’ve been told by reliableauthorities that it’s not good to refreeze uncookedmeat. Why not? If freezing the meat in the firstplace helps preserve it, why doesn’t this work thesecond time around? The answer to this question liesin the fact that all food has some bacteria in it, butnormally not enough to hurt us. We freeze uncookedmeat so that bacteria will not grow in it. Butfreezing does not kill all the bacteria that are already there, it just puts them in a kind ofsuspended animation. When the meat is thawed the bacteria come back to life and beginreproducing.

【生詞注釋】

Delayed adj.延時(shí)的, 拖延的

thaw out 融化

refreeze v. 再次冰凍

uncooked adj. 未煮過(guò)的

bacteria n.細(xì)菌

suspended animation 暫停生長(zhǎng)

reproduce v.繁殖

【參考譯文】

從商店回家的路上，你的行程延誤了，因?yàn)槟銊傎I(mǎi)的冷凍肉開(kāi)始融化。這今天的《科學(xué)時(shí)刻》的問(wèn)題是我們是否應(yīng)該再次冷凍肉?權(quán)威人士已經(jīng)告我們?cè)俅卫鋬鋈?，這種做法并不好。為什么呢?如果第一次冷凍肉能保存肉，為什么第二次冷凍就不行呢?問(wèn)題的答案在于所有食物中都有細(xì)菌，但是細(xì)菌的數(shù)量還不至于傷害我們。我們將未煮過(guò)的肉冷凍，那樣里面的細(xì)菌都不會(huì)生長(zhǎng)。但是冷凍并不會(huì)殺死里面所有的細(xì)菌，只是抑制細(xì)菌暫停生長(zhǎng)。當(dāng)凍肉開(kāi)始融化時(shí)，細(xì)菌又復(fù)活了，重新開(kāi)始繁殖。