Are food preservatives bad for you? - Eleanor Nelsen

譯者: Regina Chu 審譯者: Ann Chen

Food doesn't last.

食物不能長期保存

In days, sometimes hours, bread goes moldy,

在幾天甚至幾小時後麵包就會發黴

apple slices turn brown,

切片的蘋果變黃

and bacteria multiply in mayonnaise.

細菌在美乃滋裡孳生

But you can find all of these foods out on the shelf at the grocery store,

但是你在超市貨架上 都可以看到這些食品

hopefully unspoiled,

希望還沒壞！

thanks to preservatives.

這要感謝防腐劑

But what exactly are preservatives?

但是到底什麼是防腐劑？

How do they help keep food edible and are they safe?

它們怎麼讓食物維持可食狀態？

又安全嗎？

There are two major factors that cause food to go bad:

有二種主要原因造成食物腐敗

microbes and oxidation.

微生物及氧化

Microbes like bacteria and fungi invade food

微生物如細菌及黴菌會侵襲食物

and feed off its nutrients.

靠著食物的養分維生

Some of these can cause diseases,

有些細菌會造成疾病

like listeria and botulism.

例如李斯特菌及肉毒桿菌

Others just turn edibles into a smelly, slimy, moldy mess.

其它則讓食品變成又臭又黏的黴菌團

Meanwhile, oxidation is a chemical change in the food's molecules

氧化作用則是 食物分子產生化學變化

caused by enzymes or free radicals which turn fats rancid

酵素或自由基造成脂肪酸敗

and brown produce, like apples and potatoes.

或使農產品如蘋果或馬鈴薯褐變

Preservatives can prevent both types of deterioration.

防腐劑可以避免這兩種腐敗現象

Before the invention of artificial refrigeration,

在冰箱發明之前

fungi and bacteria could run rampant in food.

真菌及細菌可在食物內孳生

So we found ways to create an inhospitable environment for microbes.

所以我們找到了幾個方法 創造對微生物不利的環境

For example, making the food more acidic unravels enzymes

例如，讓食物更酸

會破壞微生物生存所需的酵素

that microbes need to survive.

And some types of bacteria can actually help.

某些細菌其實還幫助這點

For thousands of years, people preserved food using bacteria

幾千年來大家利用

會產生乳酸的微生物來保存食物

that produce lactic acid.

The acid turns perishable vegetables and milk

乳酸將易腐敗的蔬菜及牛奶

into longer lasting foods,

轉變成可以長久保存的食物

like sauerkraut in Europe,

像是歐洲的德式酸白菜

kimchi in Korea,

韓國的泡菜

and yogurt in the Middle East.

及中東地區的優格

These cultured foods also populate your digestive track with beneficial microbes.

這些發酵食品也能使 腸道內的益生菌繁殖

Many synthetic preservatives are also acids.

許多人工防腐劑也是酸類

Benzoic acid in salad dressing,

沙拉醬裡的安息香酸（苯甲酸）

sorbic acid in cheese,

起士裡的己二烯酸（山梨酸）

and propionic acid in baked goods.

以及烘培食品內的丙酸都是

Are they safe?

它們安全嗎？

Some studies suggest that benzoates, related to benzoic acid,

某些研究顯示安息香酸鹽 即安息香酸的相關物

contribute to hyperactive behavior.

可能會造成過動行為

But the results aren't conclusive.

但是還沒有定論

Otherwise, these acids seem to be perfectly safe.

要不然，這些酸類似乎非常安全

Another antimicrobial strategy is to add a lot of sugar, like in jam,

其它的抗菌策略還有 添加很多糖，像是果醬

or salt, like in salted meats.

或很多鹽，像醃肉

Sugar and salt hold on to water that microbes need to grow

糖和鹽會抓住微生物生長所需的水分

and actually suck moisture out of any cells that may be hanging around,

也就是將在糖鹽周圍的細胞水分吸乾

thus destroying them.

因而摧毀它們

Of course, too much sugar and salt can increase your risk of heart disease,

當然，太多糖及鹽會增加心臟病

diabetes,

糖尿病

and high blood pressure,

及高血壓的風險

so these preservatives are best in moderation.

所以要適量使用這種防腐劑

Antimicrobial nitrates and nitrites, often found in cured meats,

抗菌的硝酸及亞硝酸鹽 常常可在醃肉內找到

ward off the bacteria that cause botulism, but they may cause other health problems.

以防止肉毒症細菌孳生

但是這也會造成其它健康問題

Some studies linking cured meats to cancer

有些研究顯示醃肉之所以致癌

have suggested that these preservatives may be the culprit.

這種防腐劑可能是罪魁禍首

Meanwhile, antioxidant preservatives prevent the chemical changes

抗氧化劑也可以防止

that can give food an off-flavor or color.

造成食物變味或變色的化學變化

Smoke has been used to preserve food for millennia

煙燻也是過去數千年來 一直使用的食物保存法

because some of the aromatic compounds in wood smoke are antioxidants.

因為木頭燻煙內的某些 芳香族化合物是抗氧化劑

Combining smoking with salting was an effective way of preserving meat

煙燻加上鹽醃是冰箱發明以前

before refrigeration.

保存肉類的有效方法

For antioxidant activity without a smoky flavor,

如果你要沒有煙燻口味的抗氧化劑

there are compounds like BHT and tocopherol,

可用化合物如 二丁基羥基甲苯及生育酚

better known as vitamin E.

也就是大家熟知的維生素 E

Like the compounds in smoke, these sop up free radicals

它們就像燻煙內的化合物 可以吸乾自由基

and stave off rancid flavors

避免酸敗的味道

that can develop in foods like oils,

出現在油類

cheese,

起士

and cereal.

及早餐穀片內

Other antioxidants like citric acid and ascorbic acid

其它抗氧化劑如檸檬酸及維他命 C

help cut produce keep its color

有助於切片農產品保持顏色

by thwarting the enzyme that causes browning.

因為它會阻礙褐變酵素作用

Some compounds like sulfites can multitask.

某些化合物如亞硫酸鹽有多重功能

They're both antimicrobials and antioxidants.

可同時當抗菌劑及抗氧化劑

Sulfites may cause allergy symptoms in some people,

亞硫酸鹽可能會 讓某些人產生過敏症狀

but most antioxidant preservatives are generally recognized as safe.

但是大多數抗氧化型防腐劑 通常被認為是安全的

So should you be worried about preservatives?

所以我們應該擔心防腐劑嗎？

Well, they're usually near the end of the ingredients list

這麼說吧，它們通常位於 成分表的最後幾項

because they're used in very small amounts

因為用量非常少

determined by the FDA to be safe.

美國食藥局認定為安全

Nevertheless, some consumers and companies

儘管如此，一些消費者及公司

are trying to find alternatives.

還是在尋找替代品

Packaging tricks, like reducing the oxygen around the food can help,

包裝技巧也有幫助 如減低食物周圍的氧氣

but without some kind of chemical assistance,

然而沒有一定程度的化學幫助

there are very few foods that can stay shelf stable for long.

很少有食物能在常溫下貯藏很久

翻譯：Ｒegina Chu