Exam 2 Review - Review Exam II 2253 1 Scientific and...

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Unformatted text preview: Review Exam II 2253 1. Scientific and common name of fat types a) Mesentric Fat— Internal b) Perinephric Fat— Internal 0) Intermuscular Fat— Seam & Marbling' d) Subcutaneous Fat— External *2) inhawvscda r .. M” {ppm} 2. 4 major wholesale cuts of beef 1) Round 2) Loin 3) Rib 4) Chuck 3. Yield grades/cutability of beef Yield grades range from 1—5 — 1 = highest cutabillity (more muscle/less fat) — 5 = lowest cutabillity (less muscle/more fat) Yield Grading Factors 0 Measure Fat Thickness to get Preliminary Yield Grade (PYG) - Hot Carcass Weight (HCW) - Ribeye Area (REA) 0 Kidney, Pelvic & Heart Fat (KPH) 5.0% = +0.3 4.5% = +0.2 4.0% = +0.1 3.5% = 0.0 3.0% = —0.1 2.5% = -0.2 2.0% = —0.3 1.5% = ~0.4 4. Quality grades and marbling scores of beef A Maturin B50 Maturity C Maturity Abundant (Ab) = Prime+ (Pr+) (Ab) = (Pr+) (Ab—Md) = (Cm+) Mod. Abundant (Mab) = (Pr°) (Mab) = (Pr°) (Mt) = (CmO) Slightly Ab. (Slab) = (Pr-) (SlabSO) = (Pr-) (Sm) = (Cm-) Moderate (Md) = Choice (Ch+) (Slab40) = (Ch+) Modest (Mt) = (011°) (Md) = (Ch°) Small (Sm) = (Ch—) (Mt) = (Ch-) Slight 50A (S150) = Select (Se+) (Sm) = ($0 Slight 40v (S140) = (86-) (8190-0) = ($0 Traces (Tr) = Standard (St+) (Tr) = (St) Practically Devoid (Pd) = (St-) (PdSOA) = (St) (Pd40V) = Utility (81) = (Ut+) (Tr) = (Ut°) D Maturity (Ab—Slab) = (Cm+) (Md) = (Cm°) (Mt) = (Cm-) (Sm) = (Ut+) ($1) = (Ut°) (Tr) = (Ut—) 1.3m (Ab-Mab) = (Cm+) (Slab) = (Cm°) (Md) = (Cm-) (Mt) = (Ut+) (Sm) = (Ut°) (81) = (Ut-) B Maturity must have enough marbling to make up for a degree of maturity (ex) B30 maturity would need Slab30 to be Pr— B3O & Slab 20 = Ch+ C, D, E Maturity must have enough marbling to make up for a degree of maturity Can only be Commercial (Cm), Utility (Ut), Cutter, or Canner C0 & SmO = Cm— - C0 & 8190 = Ut+ . Maturity classes of beef (which are young & old) A— Young B- Young C— Old D—Old E— Old . Ossification‘? Thoracic Buttons (Determines Maturity) A0 0% Distifict None Red 8: Round , ,, , Separation 10% Complete Nearly Slightly Wide Compjete 3: Fiat 759599 Complete Complete Mwefafew WideStFlat ”199% Complete Complete WWW“ (watts) 7. Where beef are ribbed? Between the 12th and 13th rib 8. Bloom time? Approximately 15 min. for the oxygenation of the ribeye 9. Proteins of muscle contraction/thin & thick filament Sarcomere components (Sarcoplasmic Reticulum (SR) components) 1) Thick Filament 2) Thin Filament a) Tropomyosin b) Troponin (Calcium binds to it) 3) Z lines 4) Acetylcholine & Cholinestrase (Action Potential) 10. ATP provides energy Derived from glycolysis, TCA, and Electron Transport Chain 11. Where does calcium bind for muscle contraction? Calcium binds to Troponin l 2. Homeostasis? A) Maintenance of a physiologically balanced internal environment 1) Includes pH, temperature, oxygen concentration, energy supply 2) Activated quickly after death B) After immobilization and exsanguination, a decline in pH begins C) Postmortem pH decline has a large impact on meat color D) Stress prior to slaughter can result in abnormal pH decline, causing the meat to be light, dark, or normal 13. Lactic acid lowers pH during muscle contraction; converted from glucose A) Causes muscle pH to drop fiom 7.4 to 5.6 B) Drop in pH causes muscles to change from purple to red C) Drop in postmortem pH also affects the Water Holding Capacity (WHC) in meat 1) WHC- the ability of a muscle to retain water during cutting, hating, grinding, etc. 14. pH of Dark cutters, normal, and PSE carcasses & characteristics of each Color Glycogen at Glycogen at Lactate Final pH death 24 h production Normal 1% High 5.6 Dark 0.3% Low 6.0-6.5 Pale 0.6% . Very High 5.1 15. DFD (Dark Firm Dry) Carcasses Pork 1) Results from long term glycogen completion 2) Caused by transporting pigs long distances W/O feed 3) Depletes muscle glycogen prior to slaughter 4) Feed and rest for 24—4 8h prior to slaughter will remedy the situation Beef & Lamb 1) Caused by long—term glycogen depletion as a response to “alarm” a) Glycogen is converted to lactic acid and pyruvic acid in order to generate more ATP; initiated by adrenaline 2) Factors: exhaustion, exposure to cold, excitement, feed withdrawal, and sickness 3) Stress prevention and proper handling is best solution PSE gPale Soft Exudative) Carcasses Pork 1) Results from short-term glycogen depletion 2) Caused by swine susceptibility to PSS and to excitement a) Antemortem: Rapid glycolysis due to excitement b) Postmortem: Too long on kill floor accelerates glycogen while temp is high 3) pH of Muscle reaches 5.2 within 2 hrs 4) Solution: Decrease emphasis on heavy muscle; rest prior to slaughter & handle properly Water holding capacity WHC- the ability of a muscle to retain water during cutting, hating, grinding, etc. 16. Stages of rigor mortis Rigor Morti - Latin meaning: “Stiffness of Death” 1) Delay Phase a) ATP still present b) Muscle will remain relaxed, extensible c) No cross bridges between actin and myosin 2) Onset Phase a) ATP and Creatine Phosphate are low b) Crossbriges begin to form between actin and myosin c) As the bridges form, muscle gradually becomes less extensible 3) Completion Phase a) Creatine Phosphate is depleated b) No ATP can be formed for relaxation 0) Full rigor mortis d) No extensibility; relaxation impossible 17. Electrical stimulation - Electrical stimulation causes the carcass muscle to contract Violently and hastens the conversion of muscle to meat. The pH level drops more quickly than usual and rigor mortis sets in more quickly than in non-stimulated carcasses. ...
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