Food preservation

Question 1

The binding ability of sugars, salt and starches

Answer 1

High

Question 2

The binding ability of cellulose

Answer 2

weak

Question 3

The binding ability of proteins and lipids

Answer 3

low

Question 4

Aw that bacteria needs to grow

Answer 4

> 0.91

Question 5

Aw that moulds need to grow

Answer 5

> 0.61

Question 6

What does decreasing the Aw do

Answer 6

decreases/inhibits growth rate

increases the lag phase

Question 7

two mthods of drying

Answer 7

physcial removal

binding of water using sugars and salts

Question 8

how does pH effect microrganisms

Answer 8

effects growth and metabolism

Question 9

pH range of bacteria grow

Answer 9

3-9

Question 10

pH range of yeast growth

Answer 10

1.5-8.5

Question 11

pH range of mould growth

Answer 11

1.5-11

Question 12

name of micro-organism that requires O2

Answer 12

aerobes

Question 13

name of micro-organisms that don’t require O2

Answer 13

anaerobes

Question 14

what are facultative micro-organisms

Answer 14

can grow in the presence or absence of O2

Question 15

Intrinsic factors that affect microbe growth

Answer 15

nutrients, water activity and pH

Question 16

extrinsic factors that affect microbe growth

Answer 16

Temperature, humidity and gaseous atmosphere

Question 17

example of aerobe

Answer 17

most common bacteria

Question 18

example of anaerobe

Answer 18

clostridium Botulinum

Question 19

why does a dried apricot have high shelf stability even though it has 20% moisture content compared to salami which is 10%

Answer 19

water is bound to sugars so it cant be utilised by bacteria

Question 20

objectives of preservatives

Answer 20

extend shelf
retain nutritive value
ensure safety

Question 21

3 classes of preservatives

Answer 21

traditional
synthetic
bio preservatives

Question 22

sugar, salt, organic acids, alcohol and wood smoke are all examples of what kind of preservatives

Answer 22

traditional

Question 23

examples of synthetic preservatives

Answer 23

sorbic acid, lactic acid, benzoic acid all of which can be natural
nitrites, hydrogen peroxide, sulphites

Question 24

What are bio preservatives

Answer 24

chemical produce by a micro-organism that can prevent the growth of other micro-organisms
(chemical warfare)

Question 25

nisin and Pimaricin are examples of what kind of preservative

Answer 25

Bio Preservatives