Are food preservatives bad for you

食物防腐劑對(duì)人有害嗎？

來(lái)源視頻

Food doesn't last.

In days, sometimes hours, bread goes moldy,

apple slices turn brown,

and bacteria multiply in mayonnaise.

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

hopefully unspoiled,

thanks to preservatives.

食物會(huì)變質(zhì)

幾天時(shí)間，有時(shí)幾個(gè)小時(shí)， 面包會(huì)發(fā)霉，

蘋果塊變成褐色

蛋黃醬里的細(xì)菌繁殖

但你能在商店里的貨架上找到這些食物

希望是沒(méi)有變壞的

多虧了防腐劑

But what exactly are preservatives?

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

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

microbes and oxidation.

但是到底什么是防腐劑呢

它們是如何保持食物可食用呢？它們安全嗎？

有兩個(gè)重要的因素會(huì)導(dǎo)致食物變質(zhì)

微生物和氧化作用

Microbes like bacteria and fungi invade food

and feed off its nutrients.

Some of these can cause diseases,

like listeria and botulism.

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

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

caused by enzymes or free radicals which turn fats rancid

and brown produce, ?like apples and potatoes.

Preservatives can prevent both types of deterioration.

微生物就像細(xì)菌和真菌

入侵食物，破壞了他們的營(yíng)養(yǎng)成分

部分細(xì)菌會(huì)導(dǎo)致疾病

像李斯特菌和肉毒桿菌

其它的只是讓食物變味，變小，發(fā)霉難看

同時(shí)，氧化作用是食物分子的一種化學(xué)變化

由酶或者是導(dǎo)致脂肪變臭、食物變色的自由基引起的

就像使蘋果和土豆變成褐色（的自由基）

防腐劑可以防止這兩種形式的惡化

Before the invention of artificial refrigeration,

fungi and bacteria could ?run rampant in food.

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

For example, making the food more acidic unravels enzymes

that microbes need to survive.

And some types of bacteria ?can actually help.

在發(fā)明人工制冷技術(shù)之前

真菌和細(xì)菌可以在食物中瘋狂地繁衍

所以我們找到了些制造 一個(gè)細(xì)菌不可繁殖環(huán)境的方法

例如，讓食物變的很酸來(lái)分解酶

使食物分子能夠存活

有些種類的細(xì)菌其實(shí)可以起幫助作用

For thousands of years, people preserved food using bacteria

that produce lactic acid.

The acid turns perishable vegetables and milk

into longer lasting foods,

like sauerkraut in Europe,

kimchi in Korea,

and yogurt in the Middle East.

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

幾千年來(lái)，人們用能來(lái)保存食物的細(xì)菌

就是可以產(chǎn)生乳酸的細(xì)菌

這種酸讓易變質(zhì)的蔬菜和牛奶

變得可以長(zhǎng)期保存

像歐洲的德國(guó)酸菜

韓國(guó)泡菜

中東的酸奶

這種人造食物含有的有益分子還能促進(jìn)消化

Many synthetic preservatives ?are also acids.

Benzoic acid in salad dressing,

sorbic acid in cheese,

and propionic acid in baked goods.

Are they safe?

Some studies suggest that benzoates, related to benzoic acid,

contribute to hyperactive behavior.

But the results aren't conclusive.

Otherwise, these acids seem to be perfectly safe.

很多合成防腐劑也是酸

沙拉醬里的苯甲酸

奶酪里的山梨酸

面包里的丙酸

它們安全嗎？

有些研究表明與苯甲酸相關(guān)的苯酸鹽

會(huì)導(dǎo)致人們的多動(dòng)行為

但結(jié)論并非結(jié)論性的

此外，這些酸似乎是非常安全的

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

or salt, like in salted meats.

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

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

thus destroying them.

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

diabetes,

and high blood pressure,

so these preservatives ?are best in moderation.

另一種抗菌方法是加大量的糖，例如果醬

或者鹽，例如腌肉

糖和鹽吸附了分子生長(zhǎng)需要的水

真正的吸干了任何細(xì)胞生長(zhǎng)需要的濕度

因而摧毀了他們

當(dāng)然，大量的糖和鹽會(huì)導(dǎo)致一些疾病的風(fēng)險(xiǎn)，心臟病

肥胖

高血壓

所以這些防腐劑還是適量為好

Antimicrobial nitrates and nitrites, often found in cured meats,

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

Some studies linking cured meats to cancer

have suggested that these preservatives may be the culprit.

Meanwhile, antioxidant preservatives prevent the chemical changes

that can give food an off-flavor or color.

抗菌劑硝酸鹽和亞硝酸鹽多存在于熏肉里

它們抑制了能導(dǎo)致肉毒桿菌中毒的細(xì)菌，但是他們可能會(huì)引起其他健康問(wèn)題

一些研究把熏肉和癌癥聯(lián)系在一起

稱防腐劑可能是罪魁禍?zhǔn)?/p>

同時(shí)，抗氧化劑能夠防止導(dǎo)致食物產(chǎn)生異味

或者變顏色的化學(xué)變化

Smoke has been used to preserve food for millennia

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

Combining smoking with salting was an effective way of preserving meat

before refrigeration.

For antioxidant activity ?without a smoky flavor,

there are compounds like BHT and tocopherol,

better known as vitamin E.

Like the compounds in smoke, these sop up free radicals

and stave off rancid flavors

that can develop in foods like oils,

cheese,

and cereal.

千年來(lái)，人們用熏制的方法來(lái)保存食物

因?yàn)槭褂媚静难茣r(shí)產(chǎn)生的一些香味的合成物就是抗氧化劑

在冷凍保存之前，加鹽熏制是一種保存肉類有效的方法

如果活性抗氧化劑沒(méi)有煙熏的香味的話

有些合成物像BHT（一種常用的抗氧化劑）和生育酚

就是大家熟知的維生素E

就像煙熏中的合成物，這些吸掉了一些自由激進(jìn)分子

避免產(chǎn)生腐臭

可以在一些食物里產(chǎn)生，像油，

奶酪

和麥片。

Other antioxidants like citric acid and ascorbic acid

help cut produce keep its color

by thwarting the enzyme ?that causes browning.

Some compounds ?like sulfites can multitask.

They're both antimicrobials and antioxidants.

Sulfites may cause allergy symptoms in some people,

but most antioxidant preservatives are generally recognized as safe.

其他的一些抗氧化劑?像檸檬酸和維生素C

通過(guò)抑制酶導(dǎo)致食物變黃

幫助食物保持新鮮的顏色。

有些合成物，像亞硫酸鹽則是有多重功效

它們兼任抗菌和抗氧化的作用

亞硫酸鹽可能會(huì)使有些人產(chǎn)生過(guò)敏癥狀

但是大部分抗氧化劑通常被認(rèn)為是安全的

So should you be worried ?about preservatives?

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

because they're used ?in very small amounts

determined by the FDA to be safe.

Nevertheless, some consumers and companies

are trying to find alternatives.

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

but without some kind ?of chemical assistance,

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

所以你應(yīng)該擔(dān)心防腐劑嗎？

它們通常被列在食物成分表的最后

因?yàn)樗鼈兊姆至亢苌?/p>

是由FDA（食品藥品監(jiān)督管理局）通過(guò)的安全分量

不管怎樣，一些消費(fèi)者和公司

正在試圖找到替代品

通過(guò)包裝的設(shè)計(jì)，例如真空壓縮減少氧氣有利于保存食物

但是沒(méi)有化學(xué)物質(zhì)的幫助

很少的食物可以長(zhǎng)期保存