Meat

Question 1

Discuss 2 techniques that can be used to overcome rigor mortis in lamb

Answer 1

electrical stimulation - this accelerates rigor mortis, uses up ATP and lowers pH, can be high or low voltage in improving meat tenderness
letting the lamb hang for 7 days - this results in muscle enzymes called calpains which is responsible for post-mortem tenderisation

Question 2

Describe the structure of connective tissue that is present between muscle fibers in red meat. Identify the role of collagen in this structure

Answer 2

Epimysium surrounds the muscle fibres in read met which is the connective tissue that wrapped the muscle cell. The components of connective tissue is cells, ground substances and fibres (protein). Fascia is then a sheath of stringy connective tissue that surrounds every part of your body when it is health is provides support to joints, muscles, tendons, ligaments etc. making you more flexible as it stretches with you.
Collagen makes for tougher meat. Collagen’s role is providing structural support, maintaining muscle fibre organisation and contributing to the texture and tenderness of red meat

Question 3

Is meat genetically modified?

Answer 3

no

Question 4

when was the first shipment of frozen meat

Answer 4

dunedin to london 1882

Question 5

what is the bovine temperature

Answer 5

38.5 degrees

Question 6

does meat need a NIP (Nutritional Information Panel)

Answer 6

no

Question 7

is there is more collagen in meat what does this mean

Answer 7

tougher cuts of meat

Question 8

muscle tissue composition of red meat

Answer 8

Water 65%
Protein 19%
Intramuscular fat 2.5%
Other water-soluble compounds 3.5%

Question 9

skeletal muscle function and structure

Answer 9

Function is contraction leading to movement of body parts, helps in maintaining posture, stabilises joints, maintains balance. Structure – elongated cells parallel & well organised, a little space between the cells, filled with many myofibrils (bundle of filaments)

Question 10

skeletal muscles in larger animals consist of

Answer 10

100 um-diameter muscle fibres, each of which contains hundreds of myofibrils

Question 11

How many myofibrils per a muscle fibre and what does it consist of

Answer 11

100s-1000, consists of linear arrays of cylindrical sarcomeres (1-2 um in diameter), the basic structural units of muscle contractions

Question 12

smooth muscle function, structure

Answer 12

Walls of organs, stomach intestine, bladder

Question 13

cardiac muscle function

Answer 13

found only in the heart

Question 14

Muscle contraction in all muscle types result from

Answer 14

Interaction of myosin and actin in the muscle cell

Question 15

Contracting fibres require

Answer 15

Continuous delivery of oxygen and nutrients via arteries

Question 16

Metabolic waste is removed by

Answer 16

Veins and lymphatic system

Question 17

How does the muscle tissue connect to blood work

Answer 17

One artery and one or more veins enter with nerve (neuro-vascular bundle) and branch profusely

Question 18

what are axons of motor neurons

Answer 18

They extend from the spinal cord to the muscle. the cable transition from neurons

Question 19

what is myosin

Answer 19

Responsible for cell movements – is a molecular motor that converts chemical energy in the form of ATP to mechanical energy – generating force of movement

Question 20

what is myoglobin

Answer 20

A molecule is the muscle that dominantly contributes towards meat colour

Question 21

difference between myosin and actin

Answer 21

actin is a protein that produces thin contractile filaments within muscle cells. In contrast, myosin is a protein that produces dense (thick) contractile filaments within muscle cells.

Question 22

the sliding filament theory

Answer 22

a suggested mechanism of contraction of skeletal muscles, actin and myosin filaments to be precise, which overlap each other resulting in the shortening of the muscle fibre length. Actin (thin) filaments combined with myosin (thick filaments) conduct cellular movements.

Question 23

What is adenosine triphosphate (ATP)

Answer 23

The source of energy for use and storage of a cellular level, ATP binding and hydrolysis needed to provide energy for contractions and needed to pump calcium out of cells for relaxation

Question 24

what are 3 types of energy ATP

Answer 24

Phosphagen (immediate source) Anaerobic (somewhat slow, uses carbohydrates) Aerobic (slow, uses either carbohydrate or fat)

Question 25

What is anaerobic metabolism

Answer 25

ATP production without oxygen. occurs by direct phosphate transfer from phosphorylated intermediates, such as glycolytic intermediates or creatine phosphate (CrP), to ADP forming ATP.

Question 26

How to maintain ATP levels when circulation and nervous stimulation ceases

Answer 26

Need anaerobic metabolism – lactic acid formation - pH decreases, till glucoses runout

Question 27

difference between red meat and white meat

Answer 27

Red fibres are for sustained action, rich in mitochondria and myoglobin, has aerobic metabolism to product ATP & carbon dioxide
White fibres for short bursts, high concentration of glycogen and glycolytic enzymes, optimised for glycolysis

Question 28

what stunning technique is used before slaughter on Cows and different one for sheep

Answer 28

cattle - captive bolt
sheep - electrical stunning

Question 29

why is blood drained out of a animal when killed

Answer 29

removes haemoglobin out of animal when killed

Question 30

what does Rigor mortis mean

Answer 30

you get a huge flux of calcium ions
After death muscles and joints become stiff – actin and myosin form a complex, result of lack of ATP (can’t retrieve calcium), sarcomere length then relatively fixed (short sarcomeres {contracted muscle} usually toughens meat)

Question 31

how to slow rigor mortis

Answer 31

Accelerated cooling with blast freezing, below 10 degrees, lowers microbial growth

Question 32

what is calpains

Answer 32

Tenderisation of meat, activated by calcium rise (failure of pumps), activity detected 14 days after death

Question 33

Components of connective tissue

Answer 33

Cells, ground substance, fibres (proteins)

Question 34

what are Proteoglycans

Answer 34

Brush like structure that draws water into the tissues, to form the gel like nature of ground substance – allows tissue and fibres to slide over each other with minimal friction. Made up of proteins and polysaccharides

Question 35

What is fascia

Answer 35

A sheath of stringy connective tissue that surrounds every part of your body when it is health is provides support to joints, muscles, tendons, ligaments etc. making you more flexible as it stretches with you

Question 36

Rapid glycolysis meat colour defects

Answer 36

Pale soft exudative (PSE) meat results of rapid pH decline after slaughter particularly in stressed pigs

Question 37

Insufficient glycolysis colour defects in meat

Answer 37

Dark firm and dry (DFD) meat results from low glycogen and high ultimate pH usually from starvation or stress

Question 38

what is myoglobin

Answer 38

protein to store oxygens in the muscle cell, found in the skeletal and heart muscles

Question 39

what is metmyoglobin

Answer 39

The state when iron has oxidised to make meat a tan brown colour

Question 40

difference between grass fed and grain fed fat

Answer 40

grass fed - Yellow fat, darker flesh, beefy flavour
grain fed - White fat, pink flesh, buttery flavour

Question 41

What is ATP + what is its role in muscle movement

Answer 41

ATP is produced when sugar is used to make energy as well as fats and proteins , ATP is our primary energy source
role: ATP allows for the myosin head to move into position, bind to the actin filament and pull the actin filament in (muscle contraction). Once the actin filament is in you need anther ATP to put the myosin head out and repeat the process