food fire physics practice test
what is starch made of
Amylose molecule
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.
what creates a thicker texture amylose or amylopectin
amylopectin
Which is an example of a chemical leavener used to cause dough to rise?
baking powder
Amylose and Amylopection are two types of
carbohydrates.
The more kinks in a fatty acid carbon chain, the lower the melting temperature.
true
Approximately, how many different types of amino acids are there?
20
At what temperature below will tapioca thicken when cooked?
70
What percentage of water (water content) is raw meat?
75%
At what temperature below will tapioca thicken when cooked?
90 degrees
what is a reasonable temperature to temper chocolate?
90 degrees
Egg whites are about 90% water. When making a hard-boiled egg, what happens to that water?
A majority of water remains in the egg white, but the water is trapped in the coagulated protein network.
Polysaccharides
A polymer made up of sugar molecules
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?
Almost all of the globular proteins have denatured and coagulated.
Which answer below is the correct description of conduction?
Conduction transfers thermal energy is exchanged through collisions.
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.
What is an advantage of the sous-vide cooking approach?
It can fine tune the denaturing of proteins in the food and gives a chef great control over the texture and uniformity of the cooked food.
Some amino acids are labeled as hydrophobic. If you made a protein out of only hydrophobic amino acids, what structure would it likely have when placed in water?
It would form a tight ball and minimize the contact of the amino acids with the water.
Which is the main protein denatured in a medium-rare steak?
Myosin
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
Why can salted meats (ham, bacon, corned beef) be kept uncooked for many months as compared to unsalted meats (chicken thigh or steak)?
Salts reduce the water activity of the meat, preventing spoilage.
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 sugar dissolve in water?
The covalent bonds holding a sugar molecule together are broken by water.
The amino acid cysteine contains sulfur. Why is this amino acid important for gluten formation?
The cysteine amino acid on one glutenin molecule can form a bond (called a disulfide bridge) with a cysteine amino acid on another glutenin molecule. These bonds contribute to the gluten network.
What happens as bread is kneaded?
The process of kneading forms bonds between the proteins glutenin and creates elastic sheets of these proteins.
Tough cuts of meat require a long time to cook. Why?
The protein collagen requires both high temperature and long time to denature and hydrolyze. Tough cuts of meat have a lot of collagen.
What does it mean when a protein denatures?
The protein loses its natural structure bychemical or physical means.
After cooking meat, like a steak, it is recommended to let the meat rest at room temperature before carving. Why?
The protein network needs to relax and bind to the water in the meat.
Why can corn starch be used as a thickener?
The starch granules in the corn starch swell with water and impede the flow of water.
By pushing on a steak, an experienced chef can determine if it is rare, medium rare, medium, or well done. Why?
The steak gets stiffer as it is cooked. This occurs because the proteins in the steak denature and coagulate.
By weight, does flour contain more proteins (like glutenin and gliadin) or carbohydrates (like starch granules).
carbohydrates
What has more collagen, a chicken leg or a chicken breast?
chicken leg
which is a stronger bond covalent or hydrogen bonds
covalent
If food A is a solid at room temperature and food B is a liquid at room temperature, which one has a stronger intermolecular force of attraction.
food A because solids have a stronger force than liquids
what types of protein are in white eggs
none
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.
description of gluten.
Gluten is a protein network found in kneaded dough.
