Key Terms Ch 4

Question 1

Denaturation

Answer 1

Describes a permanent structural change of the protein molecules in food. This can occur with the application of heat, mechanical action or the addition of acids.

Question 2

Homogenisation

Answer 2

Breaks the globules of milk fat in minute particles so that the cream does not rise to the surface of the milk

Question 3

Membrane technology

Answer 3

Involves using a porous membrane or filter to separate the particles in a fluid. Two of the most commonly used form of membrane technology in food production are ultrafiltration and reverse osmosis

Question 4

Pasteurisation (HTST)

Answer 4

Destroys pathogenic or disease-causing bacteria and also extends the shelf life of milk. The milk is heated to 72°C for 15 seconds then is cooled rapidly to 2°C

Question 5

Coagulation

Answer 5

Is a form of denaturation and occurs when there is a permanent change in the protein from a liquid into a thick mass as a result of heat, or the addition of acids.

Question 6

Reverse osmosis

Answer 6

Is a form of membrane technology similar to ultrafiltration but the pores in the membrane are smaller and allow only water to pass through, leaving behind concentrated milk solids

Question 7

UHT

Answer 7

Refers to processing milk at higher temperatures than for pasteurisation , but for a much shorter time, killing all bacteria in the milk, including those that turn milk sour

Question 8

Ultrafiltration

Answer 8

Is a form of membrane technology in which milk is pumped across a membrane to collect the protein and fat and some of the calcium molecules, but the water and lactose are allowed to pass through.