Marination and safety of meat Flashcards

1
Q

Role of acid in marination

A

Reduces pH to increase myofibrillar spacing and increase WHC
Increases proteolysis by enzymes to weaken muscle structure
Increase conversion of collagen to gelatine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are other materials used for marinades?

A

Salt and phosphates
Water
Hydrocolloids
Flavourings

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How does myofibrillar protein solubilisation occur?

A

Salt causes protein to migrate to surface
Protein becomes denatured with heat
Causes coagulation and gel formation
Entraps the moisture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How does papain and bromelain work as enzymes?

A

Cleaves peptide bonds and hydrolyses collagen and actomyosin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Dry marinades use

A

Easy
Low penetration
Good on tender meats

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Wet cure use

A

Injection
Less time than dry methods

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Pastes use

A

Easy
Good crust

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the 2 types of tenderisation?

A

Mechanical and injections

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Use of injections

A

Precise and uniform
Economical

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is mechanical tenderising?

A

Tumbling and massaging under vacuum

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What are the drivers of meat colour?

A

Myofibrillar levels
Haemoglobin and cytochromes
Myoglobin is the main component as it stores and delivers oxygen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is myoglobin?

A

Iron containing protein which causes red meat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Why is red meat high in myoglobin?

A

Longer periods of activity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Why is white meat low in myoglobin?

A

Limited activity and anaerobic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are the 3 types of myoglobin?

A

Deoxymyoglobin
Oxymyoglobin
Metmyoglobin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Traits of deoxymyoglobin

A

Non-oxygenated
Ferrous iron
Dark purple

17
Q

Traits of oxymyoglobin

A

Oxygenated
Ferrous iron
Bright red as meat is cut

18
Q

Traits of metmyoglobin

A

Oxidised
Ferric oxidised iron
Brown colour

19
Q

How does curing effect myoglobin?

A

Forms nitroso myoglobin and nitrosylhemochrome

20
Q

What does spoiled meat form?

A

Sulfmyoglobin and ferrihemochrome when cooked

21
Q

When can meat become contaminated?

A

Slaughter and washing
People and equipment
Additional ingredients

22
Q

Why is fresh muscle-based food more risky?

A

Water activity, substrates and pH is compatible for microbes

23
Q

How does heat effect water?

A

Myofibrillar denaturation causes contraction and exerts force on water (decreases WHC)

24
Q

At what temperatures does collagen denature and become gelatine?

A

Denatured at 65C and changed at 95C

25
What are the ingredients used for curing?
Nitrates and nitrites Salt and sugar Polyphosphate
26
When is nitrate converted to nitric oxide?
By microbial enzyme endogenous in meat to form nitrite then to nitric oxide
27
How does meat become pink during curing?
Nitric oxide binds to metmyoglobin
28
Why is nitrite important during curing?
Protects against clostridium botulinum
29
What is the role of ascorbic acid, sodium ascorbate and sodium erythorbate?
Colour development, prevent oxidation of pigments and reduce nitrosamines
30
What are the 2 types of smoking?
Wood and liquid smoke
31
How does fermentation occur?
Carbohydrates are converted to lactic acid at the right temperature
32
How is drying used in sausages?
Removal of moisture from outside layer, drives water from inside to outside to prevent case hardening
33
What are the steps of sausage manufacture?
Meat comminution, add water (50% ice), seasonings and rusk
34
How does the protein interface effect sausages?
Solubilised protein creates thin layer around cut fat particles Denatures then prevents fat separation during cooking Thickness and composition determines stability
35
How are myofibrillar proteins different to sarcoplasmic?
High emulsifying ability
36
What is the gelling element in a sausage?
Collagen is surface active and is converted to gelatine which melts on heating and gels when cooled
37
What casings can be used for sausages?
Natural: animal intestines, permeable and expandable Artificial: cellulose, collagen, minimises contamination Peelable: smoked and coagulated films
38
How does under comminution time effect sausages?
Larger fat droplets Insufficient protein solubilised Thin interface Collagen at interface
39
How does over comminution time effect sausages?
Small fat droplets Insufficient protein to stabilise interface Fat droplets coalesce Protein damage Collagen at interface