Lecture 13 Flashcards
What are the overall consumption trends of meat consumption?
Beef decreasing
Chicken increasing
Offal remaining low
What is meat a good source of and an excellent source of?
Good:
- thiamin
- riboflavin
- niacin
Excellent:
- Fe
- Zn
- Se
- P
What is the breakdown of the composition of meat?
75% water
20% protein
5% Fat, Cholesterol and minerals
What does the composition of the meat depend on?
Cut of meat
Connective tissue
what is lean meat a good source of?
- thiamin
- riboflavin
- niacin
- tryptophan (precursor to niacin)
What is the composition and structure of meat?
Muscle Connective tissue Fatty/ adipose tissue Bone Pigments
What is a muscle composed of?
Muscle>Muscle Fibres> Myofibrils
-each myofibril is surrounded by a sarcoplasm and each fibre is surrounded by a sarcolemma
What are the tings found within a myofibril?
Proteins that form thick (myosin) and thin (actin) filaments
What do thin and thick myofilameents do?
Slide together when muscle contracts forming actomyosin
-cross-bridge is formed when they slide together, shortening the muscle
What is connective tissue?
Makes up tendons and ligaments
Needed to bind muscle cells together
What are the 3 kinds of connective tissue?
Collagen: white, non-flexible/elastic as elastin
Elastin: yellow and elastic
Reticulin: very small fibres, forms delicate network around muscle cells
What happens when connective tissue is hydrolyzed?
produces gelatin
Where do you see more connective tissue?
Tends to develop more extensivley in animals that move around more (cattle)
Which cuts of meat have more connective tissue?
Less tender cuts have more connective tissue and are less tender
What does fatty tissue vary with?
Different animals
What kind of fat do beef and mutton have?
Hard more brittle fat
Contains higher % of saturated fatty acids
What is a characteristic of softer fats?
Higher percent of unsaturated fatty acids
Why might fat be yellow in colour?
Animal feed
Animal is older
-Carotenoid pigments accumulate overtime
What are the 3 kinds of fatty tissue?
Intramuscular
Intermuscular
Subcutaneous
What is intramuscular fat?
Also called marbling
Associated with juiciness, flavour and tenderness
What is Intermuscular fat?
Between individual muscles
Seams of fat
What is Subcutaneous fat?
Found under skin
May be trimmed before sale to consumer
What is the purpose of bones?
To help identify retail cuts of meat
-back or chine bone
What are the 2 categories of bones?
Young animal: bone is red and less hard
Mature animal: bone is white and hard