preservation topic

Question 1

l

list the reasons for preserving food

Answer 1

• to keep it safe for human consumption
• to maintain and acceptable form to reduce waste
• to retain nutritional value
• to ensure perishable foods are avaliable to consumers all year around
• to achieve economic viability by reducing variations in sales and avaliability

Question 2

list the causes of food deterioation

Answer 2

• chemical
• physical
• infestation
• microbial contamination
• enzymatic

Question 3

how does chemicals cause food deterioration and spoilage?

Answer 3

the chemicals within the food causes it to break down or a contamination occurs breaking down the food.

e.g. cheese and nuts becoming rancid

Question 4

how does physical causes cause food deterioration and spoilage?

Answer 4

exposure to oxygen, light and water

e.g. bruising on apples

Question 5

how does infestation cause food deterioration and spoilage?

Answer 5

rodents and other pests causes food spoilage through damaging or contaminating the food.

(e.g. fruit flies damaging fruits)

Question 6

how does microbial contamination cause food deterioration and spoilage?

Answer 6

yeast, mould, bacteria and viruses can spoil food when the conditions are favourable, allowing them to grow and multiply.

e.g. mould on bread

Question 7

how does enzymatic reactions cause food deterioration and spoilage?

Answer 7

they speed up chemical reactions, making foods deterioate quicker.

e.g. over ripening of fruits and vegetables

Question 8

list the conditions for the growth of microorganisms

Answer 8

• low/mid pH environment
• oxygen
• moisture
• warm temperature
• nutrients
• sufficient time

Question 9

define food preservation

Answer 9

food preservation is the processing of food to eliminate the conditions that causes spoilage

Question 10

microbial activity

how does mould reproduce?

Answer 10

• through spores
• airborne, which settles on foods and grows
• grows a long stem call hyphae which penetrates beneath the surface

Question 11

microbial activity

how does yeasts reproduce?

Answer 11

• through budding
• a small bud is formed ontop of the parent bud which separates to form a new bud
• these are identical (meiosis)
• grows well in acidic environments

Question 12

microbial activity

how does bacteria reproduce?

Answer 12

• through mitosis
• parents cell splits into two cells

Question 13

microbial activity

list and describe the classes of bacteria

Answer 13

1. putrfactive: tissue decaying bacteria
2. pathogenic: produces illness/toxins which has potential to cause food poisoning
3. non-pathogenic: harmless bacteria used in food manufacturing

Question 14

compare visible and non visible food spoilage

Answer 14

Visible:
- a natural occurring process of food decomposition
- visible to the human eyes
- becomes rapid in favourable conditions
e.g. meat becoming slimy and smelly

Invisible:
- when food becomes unsafe to eat yet shows no signs

Question 15

how is food deterioration or food spoilage classified?

Answer 15

when changes occur which makes the food undesirable or unfit for human consumption.

Question 16

define food deterioration

Answer 16

refers to the loss of quality or undesirable in sensory qualities (i.e. texute, flavour or colour)

deterioration results from the action of food enzymes and/or environmental factors such as heat, light, oxygen or moisture.

Question 17

define food spoilage

Answer 17

refers to the breakdown and contamination which makes the food unfit or unsafe to eat.

Question 18

compare food spoilage and food deterioration

Answer 18

food deterioration means that the food has loss some of its quality can may seem undesirable for consumers while food spoilage means that the food has become unsafe for people to consume due to multiple factors.