muscle foods exam 2

Leaders in meat production Beef

Tyson foods, JBS, Cargill, National Beef, and Omaha Beef

leaders in meat production poultry

tyson foods, JBS, Cargill, Perdue Farms, and Koch Foods LLC

Leaders in meat production pork

tyson foods, JBS, smithfield foods, Hormel foods corp, and seaboard foods

Consumed per person per years: turkey

13.0 Ibs/person

consumed per person per year eggs

21 dozen

consumed per person per year lamb

1.17 Ibs/ person

consumed per person per year dairy

651 Ibs/ person

Manufacturing Meat

Detailed process; processing yield is vital

industry processing vs custom processing

stark contrasts; speed; yields

subprimals are influenced by retail demands

steak, roasts, grinds, and value-added

variety of names used for cut of meat

regional significance and restricted geographical areas

standardized cuts

uniform retail meat identity standards, national livestock and meat board, name consists of three parts: meat species, wholesale cuts, and retail cut

price per unit of weight

optimum price related to product movement; higher quality or further processed will equate to higher prices; most consumers make purchasing decisions on price alone

labels can vary from very simple in appearance to complex

dictated by consumers demand for information; information can be required by law; optional information a result of retailer

FSIS requires that all labels be submitted for approval

common or usual name of product, inspection legend, establishment number, name and address of processor, statement of quantity, and ingredients used in order of predominance

additional package info- date

when product is packaged and best use date, index of freshness

additional package information-grade or brand

some product marketed by USDA grade, consumers are brand conscious

Additional package information- nutrients

some consumers are concerned with nutrient content; fat, protein, vitamin, and mineral

additional package information- name of retailer

place of purchase allows product to be re-traced to origin

additional package information-universal product code

upc code provide efficiency of handling, sensors track sales, provides re-ordering flexibility

food animals can be sold on a

live weight basis or a carcass basis

selling on a live weight involved the

slaughter weight of the animal and the live price on a per hundred weight (cwt) basis

selling on a carcass basis is generally done through a

lean value program

If carcass value and dressing % are known

Live value per cwt = carcass value per cwt x (dressing % / 100)

If live price and dressing percentage are known:

Carcass value per cwt = Live value per cwt / (dressing % / 100)

lean value programs are designed to

reward superior hog producers at the expense of inferior hog producers

lean value programs pay producers on

a carcass weight basis rather than a live weight

the value of the carcass is determined by

a grid or through premiums and discounts

the majority of large companies purchase hogs on a

carcass basis

generation of wholesale cuts

distribute to various markets; fits in to the boxed meat market; achieved by standardized cutting methods

principles of meat cutting

separation of fat lean portions; separation of tough and tender sections; separation of thick and thin sections; separation of valuable cuts; and separation of retail cuts

bones are sites where CT and tendons connect muscles

used as leverage for contraction. can alter flavor profiles of meat

IMPS numbers

Institutional meat purchasing specifications

Institutional meat purchasing specifications

meat cuts standardized, described and identified for improved communication during purchasing. created by the U.S federal meat grading service

fabrication of carcasses

manageable pieces, ease in logistics, variations in further processing, and enhanced marketing

variations in further processing

grinding, cooking, marination, portioning, and packaging

cutting tests

conducted to identify pricing margins that reflect current market conditions

Water-holding capacity is defined as

the ability of meat to retain its water during application of external forces such as cutting, heating, grinding or processing

some loss of moisture usually occurs even during the mildest application of these treatments because

a portion of the water present is in the form of free water

many of the physical properties of mean are partially dependent on

water holding capacity

water-holding capacity of muscle tissue has a direct effect on

shrinkage of meat during storage

when tissues have poor WHC properties

loss of moisture and, consequently, loss of weight during storage is great. this moisture loss occurs from exposed muscle surfaces of the carcasses or cuts.

drip loss

the formation of exudate from meat or meat systems (except thawing loss) without application of external forces

thaw loss

the formation of exudate from meat after freezing and thawing without application of external forces

cooking loss

the release of fluid after heating meat either without or with application of external forces

expressible juice

the release of juice from unheated meat (also after freezing and thawing) during application of external forces such as pressing, centrifugation methods, or suction methods

WHC is especially critical in meat ingredients of

manufactured products that are subjected to combinations of heating, grinding, and other processes.

weight losses during manufacturing processes are largely the result of

water evaporation

the proper protein/water ratio is important for

palatability and adequate yield of finished product

of the total water in muscle, 4 to 5% is so located and is known as bound water

sometimes referred to as consistitutional water; remains tightly bound even during application of severe mechanical or other physical force

other water molecules are subsequently attracted to the bound molecules in layers that become successively weaker as the distance from the reactive group on the protein becomes greater

such water may be termed immobilized water, but the quantity so immobilized depends on the amount of physical force exerted on the muscle. sometimes referred to as interfacial water

water held only by weak surface forces is known as

free water

several factors influence the number of reactive groups on muscle proteins and their availability for binding water

in the immediate surroundings of the proteins, these conditions are largely consequences of postmortem changes. the specific conditions are dependent on production of lactic acid, loss of ATP, onset of rigor mortis, and changes in cell structure associated with proteolytic enzyme activity

formations of lactic acid and the resultant drop in pH in the postmortem period are responsible for

an overall reduction of reactive groups on proteins available for water binding (results in varying amounts of denaturation and loss of solubility in proteins)

reduction in numbers of reactive groups occurs because

the pH approaches the isoelectric point of myofibrillar proteins. this influence of pH is called the net charge effect

isoelectric point

that pH at which the number of positively and negatively charged groups is equal

at pH values that exist in meat (5.2 to 6.8), it is obvious that higher values are associated with

greater net charges on the protein and a greater percentage of bound of immobilized water.

in normal meat, only about ….. of the loss of WHC postmortem is due to the drop in pH

1/3

changes associated with onset of rigor mortis wherin a lack of space within the structure of proteins for water binding is known as the

steric effect

steric effect: breakdown of ATP and protein interactions associated with actomyosin formation are partially responsible for

formation of a tight network within contractile proteins

steric effect: certain ions, principally divalent cations, have the ability to

combine with and neutralize 2 negatively charged reactive groups of the proteins

steric effect: when there is little net charge on the proteins

there are few charged groups available to separate protein chains by repulsive forces

steric effect: these conditions prevent water binding by bound groups and allow protein chains to pack closely together

preventing those reactive groups that are still available from binding water

some of the loss of protein hydration caused by pH decline and rigor mortis is recovered during

subsequent storage of meat

proteolytic enzymes are probably responsible for some

subtle changes in fiber membrane permeability (may allow some diffusion of ions into areas surrounding muscle proteins)

a re-distribution of ions occurs, resulting in replacement of

some divalent ions on protein chains with monovalent ions

for every divalent cation replaced, one reactive group of protein is

freed to bind water (this exchange of ions in muscle proteins results in improved WHC)

limited improvement in WHC also occurs over time due to a

slight rise in pH(but this only accounts for a small proportion of the total change in WHC)

color as detected by the eye

is the result of a combination of several factors

hue

describes that which one normally thinks of as color (yellow, green, blue, or red) and it describes the wavelength of light radiation

chroma (purity or saturation)

describes the intensity of a fundamental color with respect to the amount white light that is mixed with it

the value of a color is

an indication of overall light reflectance (brightness) of the color

meat color is the total impression seen by the eye

and is influenced by the viewing conditions (the structure and texture of the muscles viewed also influence the reflection and absorption of light)

the only quality characteristic that consumers have to base their initial purchasing decision on is physical appearance

and meat color is one of the most influential quality factors in consumer selection

consumers relate the color of…… to freshness

lean tissue

more than ….. discoloration of a meat cut is almost 100% discrimination by the consumer

20%

the most important contributors to meat color are the pigments that

absorb certain wavelengths of light and reflect others

pigments in meat consist largely of 2 proteins: hemoglobin(the pigment of blood) and myoglobin (the pigment of muscles)

in well-bled muscle tissue, myoglobin constitutes 80-90% of the total pigment. Such pigments such as the catalase and cytochrome enzymes of the electron transport chain are also present, but their contribution to color is minor.

the 2 major pigments are similar in structure except that the myoglobin (MW 16,000) is ¼ as large as the

hemoglobin (MW 67,000)

myoglobin consists of a globular protein (globin) and a

nonprotein portion called a heme (porphyrin) ring

the heme portion of the pigment is of special interest because

the color of meat is partially dependent on the oxidation state of the iron within the porphyrin ring

myoglobin quantity varies with

species, age, gender, muscle, and physical activity

species differences are apparent when the light color of

pork is compared with the bright red color of beed

pale muscles of veal carcasses are

indicative of the fact that muscles of immature animals have lower myoglobin content than those of more mature individuals

intact males have muscles that contain more

myoglobin that those of females or castrated at comparable ages

because of muscle differences in myoglobin content

the light breast muscles of chicken contrast strongly with the dark muscles of the leg and thigh

muscle-to-muscle differences in myoglobin content are due to

the type of muscle fibers present

muscles with relatively high proportions of red fibers appear

dark red in color

when they are viewed histologically, these myoglobin-rich fibers are still seen to be mixed easily

distinguishable white fibers

dark muscles color is often simply a consequence of

a relatively high frequency of red fibers

game animals have darker muscles than domestic animals partially because of

myoglobin induction by physical activity

beef color

bright cherry red

fish color

gray-white to dark red

horse color

dark red

lamb & mutton

light red to brick-red

pork color

grayish-pink

poultry color

gray-white to dull red

veal color

brownsih pink

the reaction of pigments with several compounds or ions may result in color changes in meat;

however, the ability of pigments to combine with or tie up molecules depends on the proper chemical state of iron in the heme ring

when the iron is oxidized(in the ferric state)

it cannot combine with other molecules including molecular oxygen