fibrous Connective Tissue Flashcards
How much of body protien is collagen?
25%, inc in integument, found in heart tendons, and in muscle
tendons
joins muscle to bone
ligaments
joins bone to bone
industrial uses of collagen
leather, glue, cosmetics, food processing
structural component of collagen re muscle
works w form and shape of muscle, supports blood vessels and nerves and helps w contractile force transmission.
responsible in part for meat toughness
where is the collagen in muscle?
- sheets or cables that are visible to the naked eye
- epimysium, and perimysium within the mini fibres of muscle
tropocollagen
origin of collagen, high molecular weight, synthesized in try fibroblasts
alpha chains, structural unit of collagen. arranged in triple helix to enhance stability
tropocollagen building blocks?
Amino acids (non-essential/distensible)
- Glycine- enables tight packing
- proline and hxdroxyproline
- glutamic acid, alanine, hydroxylysine
collagen colour
individual fibre basis- colourless, in a sheath or tendon - white
collagen on animal age
young animal will have lots of new collagen as it grows/develops
- can be broken down, susceptible to heat
- high turnover bc animal is growing, breaking down and building back protiens as it grows
bone ossification
- cartilage to bone
- more insoluble connective tissue
increase of collagen X links
not as easily broken down,
- more insoluble collagen
- strong collagen
- heat stable collagen
- produces tough meat
factors that affect collagen
diet, species, gender, muscles
how does diet affect collagen
affects Xlink stability
high CHO, high fructose, low crude protien.
increases turnover in cattle by feeding high energy diets.
how does species affect collagen
amount of collagen in muscle-muscle basis, more soluble collagen in pork than beef.
how does gender affect collagen
males have more collagen
how does muscles affect collagen
the type of muscle effects the collagen - locomotive muscles have more collagen
role of tropoelastin
synthesized by fibroblasts, same as cells used to produce collagen
influences of connective tissue amounts
- functional demands of life
- connective tissue strength
- leg muscles vs backbone muscles
- muscles around backbone
- background toughness
how does cooking meat make tender muscles tough?
meat w low amounts of connective tissue gets tougher as Xlinking toughens the myofibril
how does cooking meat make tough muscles tender?
the cooking process decreases the strength of connective tissue, converting it to gelatin
how does cooking meat change juiciness
more you cook less juice, decrease due to - evaporation - drip
moisture affected by go WHC of muscle
stages of cooking effect on collagen solubility
56-65 degrees- acts on triple helix
fibrils shorten to 1/3 og length
hydrate and hydrolyse collagen
moist heat also works to tenderize meat
collagen and heat rxn
response depends on amount of collagen, types
amount of elastin in meat,
animal age - mature more resistant to breaking
what type of collagen is epimysial and perimysial and endomysial collagen?
Epi - type 1
peri - type III
endo - type 1 and III
what effects meat tenderness?
- proportions of each type of collagens
- total amount of collagen
- degree of collagen x linking
- collagen content and fibre diameter.
characteristics of tough muscle fibers
- abundant collagen around fibers
- many interfiber connections/unit SA
- heat stable Xlinks
- presence of elastin
- use of marinades to improve tenderness
- use of enzymes
methods to assess muscle tenderness
instrumental methods, sensory panels
