PHY 123 - Food, Fire, and Physics

what is a reasonable temperature to temper chocolate?

90 F

By weight, does flour contain more proteins (like glutenin and gliadin) or carbohydrates (like starch granules).

Carbohydrates

Why is it sometimes recommended to cook meat in two stages?

One stage is to brown the surface of the meat at high temperature. The other stage is to raise the internal temperature of the meat to the desired texture, which is at a much lower temperature than the surface.

Egg white begins to thicken at 145ºF/63ºC and becomes a tender solid when it reaches 150ºF/65ºC. The protein that causes this transition in texture is ...

Ovotransferrin

If potato starch has more amylose molecules than corn starch. Corn starch has more amylopectin than potato starch. Based on this information, which one do you think is a better thickener?

Potato Starch

The Onsen egg is a Japanese culinary creation in which an egg (in its shell) is cooked in a hot spring (temperature about 63°C) for a couple of hours. What is true about the globular proteins in the egg when it is removed from the hot spring?

Some of the globular proteins have denatured and coagulated, but many have not.

Why does long grain white rice become hard when cooled?

The amylose molecules in the rice align when cooled. This results in the harden texture.

Which response correctly describes the structure of a triglyceride?

Triglycerides are composed of three fatty acids bonded to a glycerol backbone.

Amylose and Amylopection are two types of ...

carbohydrates.

What is the impact of fats on gluten formation?

Fats weaken the structure of gluten and thus make the final product more tender or flaky.

Polar molecules are able to form hydrogen bonds. What is a hydrogen bond?

Hydrogen bond is an electrostatic attraction between two molecules. For example, in a water molecule, the oxygen is slightly negatively charged and the hydrogen are slightly positively charged. Thus the oxygen from one water molecule is attracted to the hydrogen of another water molecules. This is a hydrogen bond.