AS 445 Test Question and Verified
Detailed Answers Latest Update |
Graded A+
Muscle Composition - ✔✔▪75% water
▪18% protein
▪3% lipid
▪1.5% non-protein N substances
•Nucleotides (ATP & ADP), free Amino Acids, peptides
▪1% carbohydrates
•Glycogen, glucose
▪1% ash
•Iron, potassium, sodium, sulfur
what can change muscle composition? - ✔✔age, finish, area of carcass (front vs
back), species
trimmings range - ✔✔Beef:50/50 - 95/5
Pork: all fat (80% chemical fat)- 90/10
Muscle Structure - ✔✔muscle --> Muscle bundle -->muscle fibers-->myofibrils-->
sarcomere (actin and myosin)
1|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
,connective tissue - ✔✔used for jerky or ground
-flat iron steak cut with grain to avoid CT
Muscle Protein Classes - ✔✔1. Myofibrillar: (contractile and structural) actin and
myosin = salt soluble 2. sarcoplasmic: water soluble
3. stromal: connective tissue= collagen and elastin
Myofibrillar Proteins - ✔✔- salt soluble
1. contractile: actin and myosin regulated by troponin and tropomyosin
2. structural: degraded during postmortem storage;- 'aging' = tenderness
-titin, nebulin, desmin
80% of what we use
Sarcoplasmic Proteins - ✔✔•Water-soluble
•Mainly glycolytic enzymes
•Myoglobin
(Oxygen-binding protein inside muscle, Responsible for meat color, Darker color
= more myoglobin,
Heme (iron) group changes color with oxygen, oxidation, and during curing)
important for cured products- myoglobin
2|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
, Stromal Proteins - ✔✔connective tissue
1. collagen (most abundant protein in mammals)- breaks down with slow moist
cooking (major impact on meat tenderness)
2. elastin- doesn't break down (ligamentum nuchae) yellow
tough, needs to be ground
Water importance - ✔✔-largest % of meat
-meat and non meat ingredient
-eating quality
Functions in food:(palatability, protein solvent, increased yield, temp control
when grinding)
water types and % - ✔✔Free= 90-96%
Immobilized = 1-6%
Bound = .5-4%
Increase free water via pH/ion change, salts or phosphates
soluble @ low ionic strength - ✔✔Myofibrillar
-salt soluble
3|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
Detailed Answers Latest Update |
Graded A+
Muscle Composition - ✔✔▪75% water
▪18% protein
▪3% lipid
▪1.5% non-protein N substances
•Nucleotides (ATP & ADP), free Amino Acids, peptides
▪1% carbohydrates
•Glycogen, glucose
▪1% ash
•Iron, potassium, sodium, sulfur
what can change muscle composition? - ✔✔age, finish, area of carcass (front vs
back), species
trimmings range - ✔✔Beef:50/50 - 95/5
Pork: all fat (80% chemical fat)- 90/10
Muscle Structure - ✔✔muscle --> Muscle bundle -->muscle fibers-->myofibrils-->
sarcomere (actin and myosin)
1|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
,connective tissue - ✔✔used for jerky or ground
-flat iron steak cut with grain to avoid CT
Muscle Protein Classes - ✔✔1. Myofibrillar: (contractile and structural) actin and
myosin = salt soluble 2. sarcoplasmic: water soluble
3. stromal: connective tissue= collagen and elastin
Myofibrillar Proteins - ✔✔- salt soluble
1. contractile: actin and myosin regulated by troponin and tropomyosin
2. structural: degraded during postmortem storage;- 'aging' = tenderness
-titin, nebulin, desmin
80% of what we use
Sarcoplasmic Proteins - ✔✔•Water-soluble
•Mainly glycolytic enzymes
•Myoglobin
(Oxygen-binding protein inside muscle, Responsible for meat color, Darker color
= more myoglobin,
Heme (iron) group changes color with oxygen, oxidation, and during curing)
important for cured products- myoglobin
2|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
, Stromal Proteins - ✔✔connective tissue
1. collagen (most abundant protein in mammals)- breaks down with slow moist
cooking (major impact on meat tenderness)
2. elastin- doesn't break down (ligamentum nuchae) yellow
tough, needs to be ground
Water importance - ✔✔-largest % of meat
-meat and non meat ingredient
-eating quality
Functions in food:(palatability, protein solvent, increased yield, temp control
when grinding)
water types and % - ✔✔Free= 90-96%
Immobilized = 1-6%
Bound = .5-4%
Increase free water via pH/ion change, salts or phosphates
soluble @ low ionic strength - ✔✔Myofibrillar
-salt soluble
3|Page
©NINJANERD 2025/2026. YEAR PUBLISHED 2025.
