Exam 2

• Harvesting and slaughter process

• Dressing %

  • Average for different species.

• Why are values so different for dressing percentage?

  • Weight of hide

  • Head and skin left (hogs)

  • Weight/volume of intestinal content

  • Muscle mass of different species

• Humane Method of Slaughter Act of 1978:

  • Pre-slaughter management

    • Freedom from fear/stress

    • Freedom from pain

  • 12-24 hour fast

    • makes evisceration easier

    • Food safety-less bacteria from GI tract to meat

  • Free access to water

    • Helps with blood and pelt/hide removal

    • Lowers stress on animal

• Humane Method of Slaughter Act of 1978

  • The HMSA requires that food animals be handled and treated humanely at slaughter plants.

  • It also mandates a quick and effective death for these animals.

  • The act applies to all livestock except poultry.

• Types of stunning and what they do

  • Mechanical stunning- concussion or penetration, used for cattle or sheep

  • Chemical stunning- uses CO2, used for hogs or poultry

  • Electrical stunning- varies in voltage, amperage and time parameters, used for hogs and poultry.

• Pros/cons of each stunning method

  • Stun to bleeding varies with each method

  • some of them don’t always work

  • Slower per animal (electrical)

  • injuries can occur

• All the steps to slaughter process from stunning to carcass in a cooler

  • Exsanguination- bleeding

  • Scalding/skinning - removing feathers/hair/hide from specific animals (Poultry, cattle sheep)

  • Evisceration - removal of internal organs (GI, heart, lungs, liver, etc.) (for use or discard)

  • Carcass manipulation - removal of head, foreshanks, hind shanks, bruising etc.

  • antimicrobial intervention-

• Electrical stim

Specific risk material

• WHY SRM?

  • helps address areas of the animal that are specifically related to disease, and remove them

• What are SRM’s?

  • tissues in cattle that area considered to be high risk for prion contamination (cause of TSE and BSE)

  • Tonsils, and the distal ileum

  • After 30 mo of age other tissues need to be removed

• Age determination

  • Animals over 30 mo- one of the 2nd set of permeant incisors have erupted

• Can you look at the teeth and give an age estimate?

By-products and rendering

• By-products-know the different types

  • Edible, and inedible (usually pet food products)

• Example: list 4 variety meats off a beef carcass

  • kidneys, heart, liver, etc.

• Example: what is the most valuable by-product

  • the hide specifically cattle hides

Rendering industry

• Define what they do Further processing of meats

  • converts waste animal products/tissue into stable, value added materials

  • Primary byproducts- hides, fat, bones, internal organs

• Describe methods of further processing discussed in lecture

  • drying, freezing, salting, smoking, curing

• Describe curing reaction

  • myoglobin + nitric oxide = nitric oxide myoglobin + heat = nitrosylhemochromagen

• What are some curing ingredients and their functions?

  • salt- product flavor, preservative, dehydrates meat

  • sugar- flavor, counteracts the salt, provides energy for bacterial conversion, lowers acidity

  • nitrate- flavor, prevents “warmed over” flavors, slows rancidity, slows growth of clostridium botulinum, contributes pink color

• Application of curing ingredients

  • dry curing- rubbed onto meats surface, good flavor/texture, minimal equipment, no refrigeration of product, controlled bacteria, slow process, can go rancid, storage costs, increased shrinkage, salty

  • Injection curing- curing solution goes directly into meat (Stitch pumping, artery or machine), rapid penetration, reduces spoilage, adds alkaline phosphates, low salinity, flavor profile is diminished, texture is different

  • Combination curing- combines both dry and injection methods (injection with dry cure or injection with low salt liquid then add high salt pickle)

• Sausage Manufacturing

• Define sausage- any meat that of chopped seasoned and formed into a uniform shape

• Define emulsion- a dispersion of fat particles in water held by the actions of a salt soluble heat coagulable protein (SSHCP)

• SSHC proteins- Actin, Myosin, Actomyosin

• Salt-soluble because:

  • Released from within muscle during emulsion by salt solution added to mixture

• Heat coagulable because:

  • Ability to harden during cooking cycle

• During emulsion process these proteins coat the fat

• Coating of fat by proteins is important to prevent “fatting-out”

• Fatting-out-accumulation of masses of fat in one location in a cooked sausage

• Hot dogs and USDA constraints (30/10 fat/water)

Meat tenderness

• What is tenderness and how is it measured? grading scale of beef and lamb measured by the palatability (tenderness, flavor, juciness, colagen content

• Warner Bratzler shear force- the pounds of force it takes to cut ½ inch cores from cooked steaks and roasts

• How many pounds of force for tough vs tender meat?

  • tough- 12 lbs (unnaceptable)

  • marginal- 8-12 lbs

  • tender- below 8lbs

• What are factors that contribute to tenderness?

  • Species

  • Breed

  • Fat

  • Support vs locomotive muscle

  • Age

  • Water holding capacity

  • etc.

  • Be able to discuss these factors (more than just list them)

• Meat tenderness

• know the 8 QG’s

  • Prime, choice, select, standard, commercial, utility, cutter, canner

• How to determine sex class?

  • Pizzle eye and semimembranosus

• Maturity

• What are the maturity groups and what are the chronological ages related to the maturity groups? A, B, C, D, E (A being youngest and E being the oldest)

• Marbling

• What part of the beef carcass is used to measure marbling? Ribeye area

• What degree of marbling classifies a carcass as prime, choice, or select?

  • Chronological age of cattle A B C D E Feedlot cattle 30 42 72 96 Younger cows Older cows Step-wise procedure for Quality Grading Beef Carcasses

• 1. Determine the sex class of carcass

• 2. Determine carcass maturity

  • Degree of skeletal ossification in the thoracic, sacral and lumbar vertebrae

  • Color and shape of ribs

• 3. Evaluate the marbling in the ribeye and determine score

• 4. Combine marbling and maturity to determine USDA QG Beef yield grades

  • What are yield grades?

  • Relate yield grade to BCTRC

  • Know all the yield grades and the carcass composition at each grade