Lab exam of cream

Question 1

For pasteurization of cream is used (*C):

Answer 1

90*C

Question 2

Divide cream:

Answer 2

1. Cream with fat content 10% of weight, and less than 35% milk fat
2. Cream and whipped cream with fat more than 28% and less than 35% of milk fat
3. High fat cream and high fat whipped cream more than 35% of milk fat

Question 3

Flow diagram for fluid cream:

Answer 3

Raw milk (CCP residues)
Separation - 50C (skim milk)
Cream
Heat treatment (90C, 15 sec)
Vacuum removal of off-flavors
Homogenization (60-70C)
Cooling (max 6C)
Packing

Question 4

Pasteurization destroy:

Answer 4

M. tuberculosis and C. burnetti

also brucella, campylobacter, e. coli, salmonella, s. aureus and yersinia

Question 5

Goal of pasteurization is to:

Answer 5

inactivate enzymes, microorganisms and extending shelf life

Question 6

UHT sterilisation:

Answer 6

135-150*C for few seconds

Question 7

Flavour defects in cream:

Answer 7

Barny - poor ventilation, not proper covering
Bitter - bitter weeds, lipase activity, proteolytic bacteria
Cheesy - casein breakdown
Coarse-acid/sour - uncontrolled acid development
Cooked, feed and weed rancid oxidized - feeding 3 hours before milking
Fruity - bacteria
Utensil - dirty utensils
Yeasts
Cooked - excessive heating of cream
Acid/sour - sour milk, acid development
Oily/metallic - fat oxidation
Rancid - fat hydrolation
Feathering in hot coffee - excessive homogenization, using sour cream, add salts