Concentrated Dairy Products

Question 1

What is water activity?

Answer 1

The availability of free water in a food system.

Question 2

What is the scale of water activity?

Answer 2

0-1.

Question 3

What is a 0 on water activity?

Answer 3

A completely dry substance.

Question 4

What is a 1 on water activity?

Answer 4

Pure water.

Question 5

What does water activity impact in dairy products?

Answer 5

1. Chemical stability.
2. Microbial growth.
3. Physical properties.

Question 6

What are the 3 types of water?

Answer 6

1. Free/Bulk water.
2. Entrapped/Structural water.
3. Bound/Absorbed water.

Question 7

What is Free/Bulk water?

Answer 7

Unbound, mobile water, freely available for chemical reactions and microbial growth.

Question 8

What is Entrapped/Structural water?

Answer 8

Water trapped w/in a gel or solid structure, influencing texture w/o freely interacting.

Question 9

What is Bound/Absorbed water?

Answer 9

Water attached to molecules via hydrogen bonding, making it unavailable for microbial use.

Question 10

What are the 2 types of condensed milk?

Answer 10

1. Unsweetened/evaporated.
2. Sweetened.

Question 11

What % of the water is removed when making condensed milk?

Answer 11

60%.

Question 12

What type of water is increased in condensed milk when sugar is added when making condensed milk?

Answer 12

Bound/Absorbed water.

Question 13

Which is more stable: Unsweetened or Sweetened condensed milk?

Answer 13

Sweetened condensed milk.

Question 14

What is the texture of evaporated milk?

Answer 14

Thin; can be easily poured.

Question 15

What is the flavor of evaporated milk?

Answer 15

Subtle, slightly caramelized flavor from the heating process.

Question 16

What are the uses of evaporated milk?

Answer 16

Can be used in place of regular milk in recipes, adding a richer, creamier flavor.

Question 17

How is evaporated milk stored?

Answer 17

Canned and shelf-stable; must be refrigerated after opening.

Question 17

What is the process of making evaporated milk?

Answer 17

Milk is heated to remove water and then homogenized and sterilized.

Question 18

What is the texture of sweetened condensed milk?

Answer 18

Thick and viscous, like syrup.

Question 19

What is the flavor of sweetened condensed milk?

Answer 19

Creamy, richer, sweeter that evaporated milk.

Question 20

What is the use of sweetened condensed milk?

Answer 20

Desserts (pies, bars, custards).

Question 21

How is sweetened condensed milk stored?

Answer 21

Canned and shelf-stable; must be refrigerated after opening.

Question 22

What is the process of making sweetened condensed milk?

Answer 22

Sugar is added to the milk, heated to remove water, homogenized, and crystalized.

Question 23

What % of evaporated milk is water?

Answer 23

69-70%.

Question 24

What % of sweetened condensed milk is water?

Answer 24

26-30%.

Question 25

What % of sugar is added to sweetened condensed milk?

Answer 25

40-45%.

Question 26

What are the steps of evaporated milk production?

Answer 26

1. Evaporation. 2. Homogenization. 3. Cooling. 4. Intermediate tank. 5a. Canning. 5b. UHT treatment. 6a. Sterilization. 6b. Aseptic filling. 7. Storage

Question 27

What are the steps of condensed milk production?

Answer 27

1. Evaporation. 2. Homogenization. 3. Cooling. 4. Addition of lactose slurry. 5. Crystallization tank. 6. Canning. 7. Paperboard packaging alternative. 8. Storage.

Question 28

What is the % water content of milk powder?

Answer 28

2.5-5%.

Question 29

What does the water content of milk powder prevent?

Answer 29

Bacterial growth.

Question 30

What does drying milk do?

Answer 30

1. Extend its shelf life. 2. Reduce transportation costs. 3. Allows for storage of the product.

Question 31

What are the uses of milk powder?

Answer 31

1. Animal feed. 2. Baby formula. 3. Egg substitute in bread and pastries. 4. Ice cream production. 5. Mixing into dough. 6. Producing milk chocolate. 7. Producing sausage and ready to cook meats. 8. Recombination into liquid milk.

Question 32

What are the 2 commercial ways dry milk is made?

Answer 32

1. Roller drying. 2. Spray drying.

Question 33

How is roller drying done?

Answer 33

The liquid milk contacts hot rollers and the water evaporates.

Question 34

How is spray drying done?

Answer 34

The milk is sprayed against hot air. *Most common method.

Question 35

What are the benefits of freeze drying to concentrate milk?

Answer 35

1. Higher quality product. 2. Prevents changes to the milk components.

Question 36

Why is freeze drying not commonly used?

Answer 36

It has a high energy demand through the use of vacuum and freezing temperatures.

Question 37

What are the steps of creating dry milk?

Answer 37

1. Drying chamber. 2. Air heater. 3. Milk concentrate tank. 4. High pressure pump. 5. Atomizer. 6. Main cyclone. 7. Transport system cyclone. 8. Air suction fans and filters.