新闻英语视听说(Unit 1) 听力文本与练习答案

Food Quality

1

Task One: Food Additives (1)

Food additives are widely used in many countries. However, the discovery a number of years

ago that the food additive Sudan Red was harmful to human health led to a backlash against all food additives.

For example, the milk we drink in the morning has calcium added to it; numerous beverages contain calcium, magnesium, potassium, sodium and other minerals; store bought salt contains iodine, zinc and silica; and potato chips have as many as 10 types of food additives, such as spices, edible pigments, citric acid, flavor additives, sweetening agents and silica.

MSG and condiments are considered food additives. Yeast powder is also a food additive too

and is usually added to steamed breads. Even sodium carbonate is a food additive, too, and is often added to make congee.

To better understand the functions of food additives, Nature & Science did two interesting experiments at a bakery.

Flour, eggs, sugar, salt and soda are the basic materials used in baking cakes.

First, let’s make a cake without any additives. Mixing egg yolks and whites evenly, we then

add some sugar into it. When the egg and sugar are (done) being mixed, we immediately add flour, water, soda and bulking agents into the mixture and rapidly mix them to make the batter .All this must be done within 10 to 30 seconds after which the batter must be immediately placed into the oven to bake.

Now, let’s make some cakes with additives. When the eggs and sugar are being m ixed, we

add some cake oil to the mixture. The cake oil is composed of acidity regulators, antioxidants, vitamin C and sodium bicarbonate. It can make the egg-sugar mixture rapidly inflate. After flour, water and soda are poured into the egg-sugar mixture, the cake oil can form compound membranes with proteins in the cake batter. This can significantly improve the strength and stability of bubbles in the batter and make sure that all of the ingredients are evenly distributed. Even after the batter is left for some time, the bubbles will not disappear.

After the cakes are taken out of the oven we can see that the cakes that had the oil added to them are much nicer to look at and are more flexible than those without the additives. Even the insides of the cakes are remarkably different. The internal structure of the cake without additives

is uneven and brittle. But the internal structure of the cake with additives is even, soft and flexible

and tastes delicious and moist.

The benefits of food additives do not just apply to cakes but also to many other foods.

Emulsifiers are what give ice cream its delicious taste. The sweeteners lead to low-calorie,

low-sugar products.

Without edible pigments, there wouldn’t be various colorful candies.