Lecture 13 Flashcards

1
Q

What are the overall consumption trends of meat consumption?

A

Beef decreasing
Chicken increasing
Offal remaining low

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

What is meat a good source of and an excellent source of?

A

Good:

  • thiamin
  • riboflavin
  • niacin

Excellent:

  • Fe
  • Zn
  • Se
  • P
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is the breakdown of the composition of meat?

A

75% water
20% protein
5% Fat, Cholesterol and minerals

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

What does the composition of the meat depend on?

A

Cut of meat

Connective tissue

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

what is lean meat a good source of?

A
  • thiamin
  • riboflavin
  • niacin
  • tryptophan (precursor to niacin)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is the composition and structure of meat?

A
Muscle
Connective tissue
Fatty/ adipose tissue
Bone
Pigments
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is a muscle composed of?

A

Muscle>Muscle Fibres> Myofibrils

-each myofibril is surrounded by a sarcoplasm and each fibre is surrounded by a sarcolemma

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

What are the tings found within a myofibril?

A

Proteins that form thick (myosin) and thin (actin) filaments

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

What do thin and thick myofilameents do?

A

Slide together when muscle contracts forming actomyosin

-cross-bridge is formed when they slide together, shortening the muscle

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

What is connective tissue?

A

Makes up tendons and ligaments

Needed to bind muscle cells together

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

What are the 3 kinds of connective tissue?

A

Collagen: white, non-flexible/elastic as elastin

Elastin: yellow and elastic

Reticulin: very small fibres, forms delicate network around muscle cells

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

What happens when connective tissue is hydrolyzed?

A

produces gelatin

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

Where do you see more connective tissue?

A

Tends to develop more extensivley in animals that move around more (cattle)

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

Which cuts of meat have more connective tissue?

A

Less tender cuts have more connective tissue and are less tender

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

What does fatty tissue vary with?

A

Different animals

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

What kind of fat do beef and mutton have?

A

Hard more brittle fat

Contains higher % of saturated fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is a characteristic of softer fats?

A

Higher percent of unsaturated fatty acids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Why might fat be yellow in colour?

A

Animal feed

Animal is older
-Carotenoid pigments accumulate overtime

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What are the 3 kinds of fatty tissue?

A

Intramuscular
Intermuscular
Subcutaneous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is intramuscular fat?

A

Also called marbling

Associated with juiciness, flavour and tenderness

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is Intermuscular fat?

A

Between individual muscles

Seams of fat

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What is Subcutaneous fat?

A

Found under skin

May be trimmed before sale to consumer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is the purpose of bones?

A

To help identify retail cuts of meat

-back or chine bone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the 2 categories of bones?

A

Young animal: bone is red and less hard

Mature animal: bone is white and hard

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
What does the pigment of meat varry with?
Age of animal -darker in older Type of meat -pork lighter than beef
26
Why colour does myoglobin produce?
purple red | -contributes little colour to the meat cause most of the blood has already been drained off
27
What are the 3 forms of myoglobin?
Oxymyoglobin - birght cherry red - formed in presence of O2 Deoxymyoglobin - purple red - formed with little O2 Metmyoglobin - brown - holding onto water
28
What is myoglobin affected by?
Presence of O2 and light exposure - Not necessarily an indication of spoilage - Temperature is best indicator of doneness not colour
29
What things can affect colour of meat?
``` pH, meat source packaging, freezing, fat content other added ingredients ```
30
What are the classifications of beef?
``` Steer Heifer Cow Stag Bull ```
31
What is a steer?
Male castrated when young | -preferred for retail
32
What is a heifer?
Young female that has not yet given birth to a calf | -preferred for retail
33
What is a cow?
Female that has given birth to a calf
34
What is a stag?
Male castrated after maturity
35
What is a bull?
Mature male that has not been castrated | -used in processed meats
36
What is veal?
From immature cattle of at least 3 weeks and less than 20 weeks of age
37
What are the 3 classifications of lamb
Lamb: less than 12 months Yearling mutton: about 12months Mutton: passed lamb stage
38
What is rigorous mortis?
Stiffening of carcass occurs due to metabolic changes - the accumulation of lactic acid in the muscles - loss of ATP
39
What are the factors that impact rigor mortis ?
Temp Species of animal Age Activity before slaughter
40
How long does rigor mortis last in beef?
24-48 hours
41
What happens when there is low glycogen in the muscle ?
It means the animal was active befroe slaughter, so therefore therer is less lactic acid, pH would be higher and gives the meat an undesireable dark colour is produced
42
What is aging of meat?
Holding of meat after rigorous mortis is resolved - beef 11-14 days - lamb may be aged
43
What does again promote?
Increased tenderness Improved flavour and juiciness
44
What are the 2 methods of aging?
Wet aging> aged "as is" under refrigeration Dry aging> meat is packaged in a vacuum bag and held under refrigeration -more expensive
45
What is tenderness the result of?
Breakdown of proteins in the myofibrils
46
What is case ready meat?
Packaged cent5rally and then delivered to retail stores
47
What is vacuum packaged?
Reduces O2 | Purple red colour until opened
48
What is high O2 modified atmosphere?
Often sold on a tray covered with clear film, meat is bright red but will brown over time due to high O levels
49
What is low O2 modified atmosphere?
Use Carbon monoxide | -shelf life is usually longer compared to other methods, meat will remain a bright red colour for longer
50
What are the 2 governing regulation and standards that pertain to meat?
Criminal code of canada prohibits anyone from causing animals to suffer CFIA verifies that meat and poultry leaving federally inspected establishments or being imported are safe
51
How do you break down the cuts of an animal?
Primal/wholesale cuts then retail cuts - 1st division of the carcass - 2nd divided into retail cute
52
How do butchers know where to cut?
Division of cuts is made in relation to bone and muscle structure -shape and size of bones and muscle in retail cute act as a guide to identification
53
What is the IMPS?
provide standaddized meat cuts by number. Basically helps those purchasing meat for food service purchase the meat that they want and it clearly stated
54
What is involved in restructured meat?
Flaking, coarse grinding, dicing, chopping the meat Ingredients added to promote bining Meat formed into desired shape and size
55
What are ingredients the promote binding in restructured meat?
Salts, phosphates -basically used to solubilize the muscle proteins on the surface of the meat pieces. This helos witht the binding process
56
What are some examples of restructured meats?
deli meats, chicken nuggets, canadian style bacon
57
What are variety meats?
``` Sweetbreads (thymus gland) Heart Tongue Tripe Liver Kidney Oxtail ```
58
What is the difference between ground beef and hamburger?
Both are beef that is ground Hamburger has fat added to it to increase the %fat
59
What happens to the ground meat as fat decreases?
Cooking yields increase with decreasing fat content Tenderness and juiciness decrease as fat decreases
60
What is the max % fat that could be added to a hamburger?
30%
61
What bacteria is most commonly associated with ground beef?
Ecoli | -irradiated beef can help reduce the chances
62
How can you be money conscious when purchasing meat?
Economical cuts (chuck/round) Cost per pound (AP) and cost per pounds (EP) Is there a lot of fat that needs to be trimmed Bone or not
63
What does the tenderness of the meat depend on?
``` Animal maturity Post mortem aging Muscle type Marbling Marinaing Mechanical tenderization Proper cooking methods Degree of doneness ```
64
What re the 2 ways of tenderizing meat?
Mechanical: grinding/cubing Compounds: enzymes including proteinases -papain, bromeliad (more effective on collagen)
65
when happens when you have a lot of tenderizing enzymes?
Results in a mushy meat texture
66
What effects the flavour of meat?
Cooking feed Time and temp Reheating
67
How do you cure meats?
Na Nitrate Sugar Salt (produces pink pigment) Seasonings
68
Where does cured meat get its pigments from?
Nitrate+myoglobin=nitrosylmyoglibin which when reacts with heat becomes nitric oxide hemochrome (pink pigment)
69
what are cured meat pigments reactive too?
Lighirng and may discolour in lighter display areas
70
are using nitrites/nitrates in meat safe?
- links to colon cancer - Toxic when consumed in excessive amounts - found naturally (celery)
71
What is the name of the cancer causing substance from nitrites/nitrates?
Notrocinines | -vitamin C and E counteract these
72
What temp should you cook ground beef, pork/beef too?
Ground: 68-70C beef/pork/veal/lamb/roasts: 63C
73
What is not a reliable indicator of meat?
brown colour
74
what are dry meat prep methods?
``` Roasting Baking Broiling Pan broiling -best for tender cuts ```
75
where are moist meat prep methods?
Stewing Cooking in water Pressure cooking -for less tender cuts
76
What is combination cooking?
Braising | -less tender cuts
77
What is the effect of heat on meat?
``` Fat melts Myoglobin denatured at 60C Decrease capacity of muscle to hold water Tenderness changes -Decreases 40-60C -Gradual increase above 60C ```
78
What is losses in meat?
Loss of weight and nutrients which increases with increasing internal temps -greater thiamin lost in wet methods Moist heat methods result in greater losses compared to dry heat
79
What is shrinkage in meat?
Begins at 50-60C due to the shortening of muscle fibres and coagulation of proteins Increases with higher internal temps
80
What does grilling meat produce ?
Heterocuclic Amines HCAs Polycyclic Aromatic Hydrocarbons PAH Due to: - cooking well done - Burning - Charred
81
Why are HCA and PAHs bad?
associated with a higher risk of cancer, typically not recommened to eat things that are burnt or charred -But grilled fruits and veggies don’t produce the
82
How do you avoid HCA production?
Marinate, trim fat, flip meat