VOA慢速英语--食用色素:天然还是不天然?

Food Colors: Natural or Not?

The color of food can send important messages about its quality.

Now, many food companies, including McDonald’s and Kellogg’s, say they will stop adding artificial colors to their products.

McDonald’s announced in September that it had removed artificial colors from many of its hamburgers. Kellogg’s has promised to remove them from its cereals by the end of this year.

What people accept as a normal color for food can change from place to place and over time. Until the 1980s, Americans expected pistachio nuts to be red. Pistachios were mostly imported from places where the nuts were dyed to cover spots.

Now, most pistachios sold in the United States are grown in the U.S. and have natural-colored shells.

But it is not just processed and boxed foods that create illusions with color.

Cheeses

Many cheddar cheeses contain a substance added called annatto, a plant extract commonly used for coloring.

Elizabeth Chubbuck, of Murray’s Cheese in New York, said adding color comes from the time when cheesemakers in England took the butterfat from milk to make butter. The leftover¹ milk was whiter. So, she said, cheesemakers added substances to recreate butterfat’s golden color.

Another cheese that sometimes gets color added is mozzarella.

Sara Burnett is director of food policy at Panera Bread. She said mozzarella sometimes gets its bright white color from titanium dioxide, a common substance taken from nature.

Cathy Strange buys international cheeses for the food seller Whole Foods. She said the whitening is done because most mozzarella made in the U.S comes from cow’s milk, which can have a yellow color.

She said in Italy, mozzarella is sometimes made with milk from water buffalo². The milk is whiter because the animal cannot digest beta carotene, an orange nutrient³ in many fruits and vegetables.

Egg yolks

Many cooks think darker egg yolks are fresher or healthier. But the color may be the result of marigold petals⁵, alfalfa or coloring products in food for chickens.

Elizabeth Bobeck is a professor at Iowa State University. She says that yolk⁴ color is mainly caused by the carotenoids that chickens eat. Carotenoids are a natural coloring in plants. “It’s easy to change yolk colors” by simply changing what chickens eat, she said.

Bobeck added that darker yolks are not necessarily healthier. This belief may come from the idea that yolks are darker when chickens are fed fresh plants.

Salmon⁶

In salmon, a bright pink color is a sign of freshness to those buying the fish. Experts say this is why farmed salmon may have been fed food containing a man-made substance to make the flesh pinker.

The Food and Drug Administration notes that manufacturers have to declare on labeling if non-natural colors were used for salmon. For example, farmed salmon at Costco Wholesale⁷ stores is labeled “color added through feed.”

I’m Jonathan Evans.

Words in This Story

artificial- adj. not natural or real; made, produced, or done to seem like something natural

dye –n. a substance used for changing the color of something such as hair or cloth usually permanently⁸

illusions –n. something that looks or seems different from what it is; something that is false or not real but that seems to be true or real

digest – v. to change food that you have eaten by a biological process into simpler forms that can be used by the body

yolk – n. the yellow part in the center of an egg

labeling –n. a word or phrase that describes or identifies something or someone

1 leftover   

n.剩货，残留物，剩饭；adj.残余的

参考例句：

• These narrow roads are a leftover from the days of horse-drawn carriages.这些小道是从马车时代沿用下来的。
• Wonder if that bakery lets us take leftover home.不知道那家糕饼店会不会让我们把卖剩的带回家。

2 buffalo   

n.(北美)野牛；(亚洲)水牛

参考例句：

• Asian buffalo isn't as wild as that of America's. 亚洲水牛比美洲水牛温顺些。
• The boots are made of buffalo hide. 这双靴子是由水牛皮制成的。

3 nutrient   

adj.营养的，滋养的；n.营养物，营养品

参考例句：

• Magnesium is the nutrient element in plant growth.镁是植物生长的营养要素。
• The roots transmit moisture and nutrient to the trunk and branches.根将水分和养料输送到干和枝。

4 yolk   

n.蛋黄，卵黄

参考例句：

• This dish would be more delicious with some yolk powder.加点蛋黄粉，这道菜就会更好吃。
• Egg yolk serves as the emulsifying agent in salad dressing.在色拉调味时，蛋黄能作为乳化剂。

5 petals   

n.花瓣( petal的名词复数 )

参考例句：

• white petals tinged with blue 略带蓝色的白花瓣
• The petals of many flowers expand in the sunshine. 许多花瓣在阳光下开放。 来自《现代英汉综合大词典》

6 salmon   

n.鲑，大马哈鱼，橙红色的

参考例句：

• We saw a salmon jumping in the waterfall there.我们看见一条大马哈鱼在那边瀑布中跳跃。
• Do you have any fresh salmon in at the moment?现在有新鲜大马哈鱼卖吗？

7 wholesale   

n.批发；adv.以批发方式；vt.批发，成批出售

参考例句：

• The retail dealer buys at wholesale and sells at retail.零售商批发购进货物，以零售价卖出。
• Such shoes usually wholesale for much less.这种鞋批发出售通常要便宜得多。

8 permanently   

adv.永恒地，永久地，固定不变地

参考例句：

• The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
• The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。