Animal Science 460 Exam 2

Front 1

The three approaches to meat color measurement are..

Back 1

Light absorbance methods, light reflectance measurements, and human panel assessments

Front 2

Light reflectance measurements

Back 2

Measures light reflected from surfaces

Front 3

The three characteristics of any color that can be measured and reproduced

Back 3

Color perceived (dominant wavelength), lightness/darkness of the color (lightness), and intensity of the color (chroma)

Front 4

The Hunter color reflectance measurement system uses what three letters? What do each mean?

Back 4

L*= lightness, a*= redness (+) --> green (-), b*= yellow (+) --> blue (-)

Front 5

Any of various naturally occurring extremely complex substances that consist of amino acid residues joined by peptide bonds

Back 5

Protein

Front 6

Performing or being able to perform a function.. concerned with actual use rather than theoretical possibilities..

Back 6

Functionality

Front 7

The combination of properties that affects the utilization and performance of the protein in a finished product

Back 7

Protein functionality

Front 8

Protein functionality has the ability to..

Back 8

bind and retain fat and water through the manufacturing process and during storage, and.. to create the desired texture in the finished product at the point of consumption

Front 9

Foods or ingredients that provide an additional physiological benefit beyond their basic nutrition

Back 9

Functional Foods

Front 10

Protein properties of interest for functionality in processed meats

Back 10

H2O binding/moisture retention, protein solubility and extractability, emulsion/batter forming ability, and gelation properties. (color?)

Front 11

Factors that determine protein functionality

Back 11

Intrinsic factors- dependent on protein source. (Amino acid composition, amino acid sequence, molecular size, shape, conformation, and flexibility)

Extrinsic- environmental factors (pH, salts, temp, redox potential, role of processing technology, ect.)

Front 12

Structural, contractile proteins (Myosin, actin)

Back 12

Myofibrillar proteins

Front 13

Long filamentous molecule, ~4,500 amino acids, 6 polypeptide chains. Highly functional blend of hydrophobic and hydrophilic amino acids and a tertiary structure that facilitates interactions with polar and non-polar media

Back 13

Myosin

Front 14

Globular structure, ~375 amino acids. Less functional than myosin, at least 4 isoforms in muscle, and probably reduces myosin functionality somewhat as actomyosin in postmortem muscle

Back 14

Actin

Front 15

3rd most abundant myofibrillar protein, largest protein with over 34,000 amino acids, connects end of myosin filaments to Z-lines

Back 15

Titin (Connectin)

Front 16

Supporting connective tissue between muscle fibers, bundles, and individual muscles (Collagen).

Back 16

Stromal proteins

Front 17

3 polypeptide chains in a long filamentous molecule, highly crosslinked, nonpolar amino acids, nonfunctional

Back 17

tropocollagen

Front 18

Water holding ability

Back 18

Encompasses inherent and added water, affects yields, appearance, and palatability.

Front 19

Solubility and extractability

Back 19

not so critical by itself but represents a precondition for other functions particularly emulsion films, adhesion of meat pieces, and gelation.

Front 20

Solubility and extractability is affected by

Back 20

Intrinsic pH, ionic strength, and added water, fiber type and species, and mechanical input.

Front 21

Emulsion/batter stability requires..

Back 21

interfacial protein film for raw stability and protein gelation for cooked stability

Front 22

Gelation

Back 22

Critical to finished product properties by providing trapping/retention of water and fat adhesion and mouthfeel of cook products

Front 23

Second most abundant component in meat-- by far the most variable

Back 23

Fat/Lipids

Front 24

Rancidity often begins with.. (located in cell membranes)

Back 24

Phospholipids

Front 25

Lipid/fat characteristics that are important to meat processing

Back 25

Softness-melting point, free fatty acids, breakdown products of fat which indicated flavor problems, fat/lipid is important to palatability, structural component, economics, nutritional

Front 26

Softness of lipids is dependent on.. and is measured by..

Back 26

fatty acid chain length and number of double bonds, and saponification number and iodine number

Front 27

Breakdown products of fat which indicate flavor problems

Back 27

Peroxides (result of rxn of oxygen with fatty acids, peroxide value), and aldehydes/ketones (actual rancid flavor components, malonaldehyde, TBA #, TBARS)

Front 28

Development of rancidity

Back 28

1) Enzymatic, 2) hydrolytic, 3) oxidative rancidity (auto-oxidation)

Front 29

Release of free fatty acids from glycerol

Back 29

Hydrolytic

Front 30

Oxygen reacting with unsaturated fatty acids to produce aldehydes and ketones

Back 30

Oxidative rancidity (auto-oxidation)

Front 31

Auto-oxidation sequence

Back 31

1) Initiation (extraction of H+ from fatty acid to form a free radical R)

2) Propagation (free radical reacts quickly and easily with oxygen to form hydroperoxy radical)

3) Termination of the sequence (Radicals can run into each other, react, and terminate the cycle.

Front 32

Breaks down into aldehyde and ketones giving the nasty flavors and odors of rancid products

Back 32

Hydroperoxide (ROOH)

Front 33

Control points for auto-oxidation rancidity

Back 33

1) Fatty acid saturation

2) Avoid raw materials that may have already gone into initiation

3) Reduce initiators

4) Eliminate oxygen (Vacuum processing/ vacuum packaging)

5) Provide antioxidants (Will react with radicals to terminate the cycle)

Front 34

Major antioxidants available for meat applications

Back 34

1) "Synthetic" antioxidants (phenolics)

2) Synergists- "Secondary"

3) "Natural" antioxidants

4) Others..

Front 35

Initiation site of H extraction

Back 35

Carbon adjacent to double bond. (Differs for other unsaturated fatty acids)

Front 36

Options in sensory panel analyses

Back 36

1) Trained (Small, 10-20 trained people)

2) Consumer (Large, 100+, highly variable)

Front 37

General guidelines for panels

Back 37

1) Sample selection- representative

2) Sample handling (cooking, serving temperature, appearance, sanitation, safety)

3) Selection of panelists (age, sex, diet, color-blindness, ect.)

4) Lighting

5) Isolation

6) Standar/ clearing agents

7) Sample Codes

8) Limit samples to ~9 max at one time

9) Use appropriate scale

10) Randomize order of samples evaluated

Front 38

Scale used for evaluation

Back 38

Hedonic scale

Front 39

Method concepts used for sensory evaluations by taste panels

Back 39

a) preference- most done with large, untrained consumer panels

b) Discrimination- determines how products perceived and significance of difference. (Trained)

c) Descriptive methods- discrimination of qualitative and quantitative traits of a sample by use of a small member, very highly trained panel

Front 40

Panelists receive three coded samples, two of the samples are the same and one is different, panelists identify odd sample

Back 40

Triangle test

Front 41

Three sample are presented: one sample is labeled reference "R", and the other two are coded. One of the samples is identical to "R" and the other one is different. Panelists identify the sample that is same or different.

Back 41

Duo-Trio test

Front 42

A pair of coded samples is presented for comparison on the basis of some specified characteristic

Back 42

Paired comparison test

Front 43

An extension of paired-comparison tests. Panelists receive three or more coded sample and are asked to rank samples for intensity of some specific characteristic

Back 43

Ranking test

Front 44

Scale Scoring using Hedonic scale

Back 44

Usually 9 points, 1=extremely undesirable, 9=extremely desirable

Front 45

Flavor profile

Back 45

Provides a total picture or profile of a food product.

Front 46

Texture measurements

Back 46

1) Human panels

2) Texture instruments ( Instron, Texture Analyser, TPA)

Front 47

Texture measurements

Back 47

1) Compression

2) Penetrations/ puncture

3) Shear

4) Extrusion

5) Tension

6) Breaking/bending

7) Texture Profile Analysis

Front 48

Two-bite test

Back 48

Used in a TPA, uses compression, release, recompression and re-release

Front 49

Emulsion/batter stability is determined by

Back 49

1) Meat quality (myofibrillar protein content and functionality)

2) Handling knowledge and technology (appropriate use of salt, temp, ect)

3) Additional binders to help stabilize emulsion/batters and control physical properties

Front 50

Stable dispersion of one immiscible liquid in another

Back 50

Emulsion

Front 51

Fat binding

Back 51

1) Fat cell walls

2) Emulsification membranes

*Proteins rearrange somewhat and consequently lose some water binding ability.

3) Heat-set gelation- crosslinking proteins to form a 3D matrix

Front 52

Three components necessary for emulsion/batter

Back 52

1) Internal phase (fat)

2) External phase (water)

3) Emulsifier (protein)

Front 53

Max amount of fat or oil stabilized by a given amount of protein

Back 53

Emulsion/batter capacity

Front 54

Amount of fat or oil retained (or separated) after stressing, usually w/ heat, a formed emulsion/batter

Back 54

Emulsion/batter stability

Front 55

In Stokes Law..

Back 55

smaller fat globules are more stable and require more protein, greater viscosity is more stable.

Front 56

Non-meat ingredients

Back 56

1) H2O

2) Salt

Front 57

Salt dietary guideline (2015) Dietary Guidelines for Americans

Back 57

Daily sodium intake to 2,300mg