Dairy

Question 1

Milk preservation

explain the process of pasturisation.

Answer 1

milk is heated to 75 degreses for 2 seconds, then rapidly cooled to 5 degrees.

Question 2

Milk preservation

what happens when milk is pasturized?

Answer 2

most pathogenic bacteria are destroyes, increasing shelf life without much effect on flavour. most pasturised milk is homogenised.

Question 3

Milk preservation

explain the process of UHT treatment

Answer 3

milk is heated to at least 135 degrees for 1 second to destroy all harmful bateria. its then packaged into sterile containers which can be stored, unopened at room temperature for up to 6 months

Question 4

Milk preservation

explain the process of condensed milk.

Answer 4

fresh milk isheated to 110 - 115 degrees for 1-2 minutes, homogenised and sugar is added. it is evaporated at 55-60 degrees,then cooled rapidly to 30 degrees and canned

Question 5

Milk preservation

describe condensed milk

Answer 5

very thick and sweet

Question 6

Milk preservation

explain the process of evaporated milk

Answer 6

50% of the water is evaportaed form milk, then it is homogenised and poured into cans which are sealed the heated for 10 mins at a high temp, giving a slight carael flavour and rich golden colour

Question 7

Milk preservation

explain the process of sterilising milk

Answer 7

milk is heated to 50 degrees, homogenised, poured into glass bottles and closed with an air tight seal. They are heated to 119-139 degrees for 10-30minutes, then cooled,

Question 8

Milk preservation

how long does sterilised milk keep?

Answer 8

unopened at room temp for 6 months.

Question 9

Milk preservation

explain the process of dried milk.

Answer 9

milk is homogenised, heat treated, concentrated and dried. it is sprayed into a chamber of hot air, causing the droplets of milk to lose their water content and fall to the floor of the chamber as dried milk powder.

Question 10

Milk preservation

how long can dried milk be kept?

Answer 10

it can be stored at ambient temperatures for a year but once reconstituated it must be treated like fresh milk.

Question 11

Milk preservation

define homogensied

Answer 11

a process which forces pasturised milk under pressure through a very fine mesh. this breaks up the alrge fat globules into smaller ones which are more evenly distributed through the milk.