meat science exam 3

Know the definitions of growth and how we measure it

• A positive change in size and/or maturation over a period of time

• A quality that can be physical (height and weight) or abstract (maturation)

Population growth

• Human population

• Cell culture or bacterial population

Organismal growth

• Total growth

• Growth rate

• Fractional growth

Know the basic definition of hybrid vigor

Increased performance (vigor) of the offspring over the average performance of the parents when unrelated individuals are mated.

Common gas types used for MAP packaging

• oxygen

• carbon dioxide

• nitrogen

Hyperplasia

the enlargement of an organ or tissue caused by an increase in the reproduction rate of its cells (increase in cell number)

Hypertrophy

the enlargement of tissue or organ due to increase in cell size

Be able to define the shape of the standard growth curve

sigmoidal curve

Know the priority of nutrients in tissues

1. Nervous
2. Skeletal
3. Muscle
4. Fat

The higher the plane of nutrition, the quicker optimal composition is reached. Understand how this may differ by feed type, influencing growth rates

- for grass-fed beef, it takes longer for them to reach their peak weight

- for concentrate fed beef, they reach their peak weight faster

Know the 2 common hormones added to implants

• steroid hormones

• progestins

Know the 3 “legs” making up palatability

• flavor

• tenderness

• juicyness

Taste

Comprised of five basic tastes - Salty, sweet, bitter, sour, umami

Aroma

Combination of taste and smell

- First perceived by nostrils

- Volatile flavor compounds transfer to olfactory receptors

Trigeminal Sensory System

Responsible for detecting irritants in the throat and nose

Meat browns during cooking because of the

Maillard Reaction

What types of cattle have greater amounts of calpastatin?

bos indicus cattle

The number 1 quality concern to consumers (in terms of palatability)

tenderness

Understanding the relationship between Kg/f and tenderness

• less shear force = tender

• more shear force = tough

Pros and cons to using plant enzymes

pros: can further help to degrade muscles and connective tissues

cons: product becomes too soft or mushy, develops off flavors sometimes

Maximum tenderness is achieved after approximately how many days?

20.5 days

Primary protein causing meat color

myoglobin

The time between deoxy- and oxymyoglobin

bloom time

What compound is bound to myoglobin in each state of the color triangle

deoxymyoglobin - not bound

oxymyoglobin - O2

metmyoglobin (oxidized) - H2O

carboxymyoglobin - CO

Ferrous iron

• “Good” colors

• Desirable as a consumer

• Deoxymyoglobin and Oxymyoglobin

Ferric iron

• “Bad” colors

• Less desirable as a consumer

• Metmyoglobin and Sulfmyoglobin

Be able to list and describe at least 3 factors to consider when determining growth rate of an animal

- frame size

- production type

- sex class

Understand, in depth, the muscle mutations we talked about in cattle and sheep

sheep: callipyge (Phenotypically heavier muscled loins and legs)

cattle: double muscling (A mutation of the myostatin gene - this gene encodes for growth regulation)

Factors for quality grading

• maturity - carcass age (skeletal, lean maturity)

• marbling - intramuscular fat (amount, dispersion)

How to determine cutability

in pork: yield grades 1-4

in cattle: yield grades 1-5

lower numbers = higher cutability

What yield and quality grades estimate

quality grade - estimates palatability

yield grade - estimates amount of usable, lean meat on a carcass

Strongest and weakest cure flavors

strongest - dry cure

weakest - cover pickle

Requirements of bacon product

1. come from the belly of pork

2. smoke and chilled weight = green weight

3. 120 ppm nitrite

4. 550 ppm erythorbate