Physico chem prop of milk

Question 1

book by Sukumar De

Answer 1

Outlines of Dairy technology

Question 2

physical state of components of milk are all in solution

Answer 2

No
dissolved or suspended

Question 3

Protein
Fat
Minerals
Lactose
physical state

Answer 3

Colloidal suspension
Emulsion
Solution like lactose / colloidal suspension like protein
solution

Question 4

Physica; state of mineral salt is emulsion and solution?

Answer 4

No
Colloidal supension and solution

Question 5

…..is used to assess perishability of milk

Answer 5

acidity

Question 6

fresh milk is …….

Answer 6

amphoteric

Question 7

if basic red lithmus turns

Answer 7

blue

Question 8

what contributes to apparent accidity

Answer 8

Citrates
Acid phosphates
Casein

Question 9

What is apparent acidity

Answer 9

Natural/ Apparent/ Titrable acidity
TAN

Question 10

TAN is due to

Answer 10

casein
Acid phosphate
Citrate

Question 11

Real acity is actually NAtural acidity?

Answer 11

No
real acidity= Developed acidity

Question 12

Total acidity is expressed as percentage of ….

Answer 12

Lactic acid

Question 13

what is the titrable acidity and pH of cow’s and
Buffaloe’s milk

Answer 13

0.13-0.14 - 6.4- 6.6
0.14-0.15 - 6.7-6.8

Question 14

what does a lower pH than normal indicates
What does more alkaline pH indicate

Answer 14

bacterial spoilage
sub clinical mastitis

Question 15

why pH of sub clinical mastitis cow milk is alkaline

Answer 15

Na ion seaps into mik from blood in udder

Question 16

temperature doesn’t affect specific gravity of Milk

Answer 16

false

Question 17

the standard temp at which Specific gravity is measured in milk

Answer 17

15.6 degree celcius
60 deg fahrenheit

Question 18

Hydrostatic balance is used to measure ….. of milk for which … is also used

Answer 18

Specific gravity
Pycnometer

Question 19

principle or method used by hydrostatic balance is : determining ….. of known …..

Answer 19

weight of known vol

Question 20

principle behind pyconometer

Answer 20

determining Weight of known Vol

Question 21

working principle of Lactometer

Answer 21

determining Vol of known weight

Question 22

Sp gravity can be measured using …/…. and ….

Answer 22

pycnometer= hydrostatic balance & lactometer

Question 23

Sp gravity of cow’s milk
buffalo’s milk
skimmed milk

Answer 23

1.028- 1.030
1.030- 1.032
1.035- 1.037

Question 24

Mean value of Sp gravity of milk at market

Answer 24

1.030

Question 25

relation between fat, SNF and Sp gravity

Answer 25

fat~1/Sp gravity SNF~ Sp gravity

Question 26

SNF and Natural acidity and why

Answer 26

SNF~ Natural acidity SNF= casein, Citrate, acidic phosphate

Question 27

Fat and Sp gravity are inversely proportional yet buffalo with higher fat perc than cow still has higher sp gravity ....why?

Answer 27

Buffalo has Higher SNF content than cow's

Question 28

to increase Sp gravity cream / water can be added ?

Answer 28

false cream= fat decreases Sp gravity water addition reduces SNF/ solute conc which also reduces Sp gravity

Question 29

dding whey/ skimmed milk ...sp gravity

Answer 29

increases skimmed milk is low in fat..lower fat means higher Sp gravity

Question 30

freezing temp of milk is > water

Answer 30

false milk freezes at a lower temp -5 deg celsius

Question 31

why freezing temp of milk is lower than 0 deg celsius

Answer 31

more solutes more lowering of temperature needed

Question 32

Depression in freezing point of milk indicates

Answer 32

milk freezing at a temp lower than (-5) that of water (0 deg)

Question 33

usual relation between Freezing point and Freezing point Depression is direct?

Answer 33

false inverse

Question 34

Adding water increase / decreases fp? what about Freezing point depression

Answer 34

adding water increases Fp and Decreases FPD adding water..... more water like so shifts from -5 to more positive or higher temp

Question 35

what all can increase FP (decrease FPD) of milk

Answer 35

increase fp means more positive adding waterhat

Question 36

can reduce FP

Answer 36

reduce means more negative/ more cold (more milk like) souring boiling (solutes increases -lowers temp) sterillisation "