Milk Study Guide Key

Name Period Assign#

  1. The sugar in milk is called

lactose

  1. The B vitamin in milk that is affected by light is

riboflavin

  1. Milk is fortified with

Vitamin D

  1. The process of heating milk to destroy harmful bacteria is

pasteurization.

  1. The milk product that is made by pasteurizing skim milk and then treating it with lactic acid bacteria is

buttermilk.

  1. The main mineral in milk is calcium. Its function is to build strong

bones and teeth.

  1. If you were to take light cream and treat it with certain organisms to produce a thick, creamy substance with a distinct flavor, what would you be making?

Sour cream.

  1. What are the two main groups of proteins in milk?

Casein and serum (whey) proteins.

  1. Why does milk have a white color?

Light reflected from the micelles makes milk white.

  1. Explain why acid causes milk to curdle.

When acid is added to milk, the casein proteins separate from the rest of the liquid and the milk curdles. This happens because the calcium and magnesium ions which make the casein micelles stable are removed from the casein micelles when acid is added to milk.

  1. How is milk homogenized?

The milk is forced through very small holes under pressure which separates the fat globules into small enough pieces and distributes them so evenly that they do not clump together as the milk sits.

  1. What does the enzyme lactase do, and why is this necessary when digesting milk?

Lactase breaks lactose down into lactose and galactose. If the digestive tract does not have this enzyme, the lactose ferments in the digestive tract because the person can not absorb the lactose and burn it for energy.

  1. What is the relationship between the viscosity of whipping cream and the temperature of the cream?

The colder the cream, the greater the viscosity of the cream.

  1. What is the relationship between the viscosity of whipping cream and the amount of butter fat in the cream?

The higher the fat content, the greater the viscosity of the cream.

  1. What technique/s can be used to prevent milk from scorching when cooking?

Cook milk over low heat or use a double boiler.

  1. What technique/s can be used to prevent a skin from forming when cooking milk?

Stir constantly while cooking, use low heat, create a foamy surface on the milk by adding a marshmallow, beating, or adding a fat to the milk.

  1. What technique/s can be used to reduce the chance that milk will curdle when cooked?

Using low heat to cook, increasing the pH of the milk product being cooked, reducing the amount of salt used when milk is hot, thickening the milk before an acid is added to it, heating the milk and the acid separately and then mixing them together.