Ingredients Flashcards
What is the major protein found in milk, and its percentage?
Casein. It makes up about 85% of the protein.
The remaining 15% is the Serum or Whey proteins.
What is the sugar found in milk?
Lactose. (When people are lactose intolerant, it means they cannot digest this sugar)
What is the purpose of pasteurizing milk?
The purpose of pasteurization is to eliminate disease-causing micro-organisms, however, some lactic acid bacteria may remain.
How does a homogenizer work?
The homogenizer forces milk through a very fine nozzle at a high temperature. This breaks down the fat globules into 1/10 their original size. This increases the dispersion of fat as each fat globule absorbs a layer of protein and lecithin, exerting a negative charge that repels other fat globules. Therefore the globules no longer clump together.
Why does milk sour?
If milk is improperly stored, lactic acid bacteria multiplies until the concentration makes the milk sour.
What are the correct storage conditions for fluid milk?
Fluid milk must be kept cold, at 2-4C, in a closed container
What is the reconstitution ratio for Whole Milk?
1: 7
powder: water
What is the reconstitution ratio for Skim Milk?
1: 10
powder: water
What is buttermilk?
Buttermilk was originally the liquid remaining after butter was churned. Today it is a lactic acid cultured milk, fermented to the appropriate acidity before being cooled and salted.
What is whey?
Whey is the liquid that remains after the casein and the butterfat are removed when cheese is made.
Cheese made from sweet milk will leave a sweet whey.
Cheese made from sour milk will leave a sour whey
What is Evaporated Milk?
Evaporated milk is partially dehydrated whole milk, with the liquid (60%) removed in a vacuum, before being homogenized, canned, sterilized (118C), and given stabilizers to keep the product smooth. It has a yellow appearance and cooked flavour
What is Sweetened Condensed Milk?
Sweetened Condensed Milk is similar to evaporated milk, in that it has had water (60%) removed. It has the addition of 44% sucrose and/or dextrose, and does not need to be sterilized at high temperatures because the sugar will act as a preservative.
What are some advantages of using dried milk over liquid milk?
- Longer shelf life, does not sour
- Easy to store, can be stored at room temp
- Convenient
- Economical
- Reconstituted to any concentration
What are the 2 methods of drying milk called?
- Drum/Roller drying
2. Spray drying
Describe the process of Drum/Roller drying milk.
- Milk is preheated, pasteurized, and fed into a vacuum chamber.
- The milk is passed over 2 steam-heated rollers, revolving in opposite directions. As the milk dries into a thin film, it is removed by the blades.
- The powder then goes to a hammer mill, where it is reduced to granules.
What is a disadvantage of Drum/Roller drying milk?
Drum/Roller dried milk is not very uniform and may be gritty.
Describe the process of Spray drying milk.
- Milk is heated to 190C, then condensed in a vacuum pan
- Milk is forced under great pressure into the drying chamber
- The water evaporates, and the milk granules fall to the bottom, where they are removed.
This method produces a good product that is fine, powdery, and easily dissolved.