Consumers expect high quality meat, which should have desirable flavor, tenderness, and juiciness.

MEAT QUALITY

Color Flavor

Tenderness

Juiciness Palatability- affects consumers’ repeated purchase of meat

First factor- Consumers judge

freshness and wholesomeness of meat.

1. POST - HARVEST FACTORS & STRATEGIES

PRACTICAL APPLICATIONS TO IMPROVE

FRESH MEAT COLOR

2. PRE - HARVEST FACTORS & STRATEGIES

1. TEMPERATURE

I. POST- HARVEST FACTORS

INFLUENCE OF CARCASS CHILLING TEMPERATURE ON MEAT COLOR

High pre-rigor temperature (42°C) significantly reduced the retail color display life of chilled lamb loins.

(Rosenvold & Wiklund, 2011)

Redness (a* value)

0 3 6 7 88

10

12

14

16

18

20

ES

NES

Retail display in 80% O2/20% CO

2 (days)

0 3 6 7 88

10

12

14

16

18

5°C

15°C

25°C

42°C

0

5

10

15

20

25

30

35

40

NES 15°C ES 15°C NES 38°C ES 38°C

L*

Treatment

Effects of electrical stimulation (ES) and different pre-rigortemperatures (15 and 38°C) on L* (lightness) values ofbeef M. longissimus. (Kim et al., 2014)

a ab b

INFLUENCE OF CARCASS CHILLING TEMPERATURE ON MEAT COLOR

SSM:Fast chilling

DSM:Slow chilling

0

10

20

30

40

1 3 5 8 24

Te

mp

eratu

re

(°C

)

Post-mortem Hour (h)

DSM

SSM

5.4

5.6

5.8

6

6.2

6.4

6.6

1 3 5 7 9 11 24

pH

Time postmortem (h)

DSM

SSM

HIGH TEMPERATURE & RAPID pH DECLINE CONDITIONS RESULT IN MYOGLOBIN DENATURATION

Two-toned color

development

High Temp & fast pH decline conditions

Protein denaturation: myoglobin denaturation

DSM

SSM

MORE DISCOLORATION OF DSM DURING RETAIL DISPLAY

DSM SSM SEM

L* 46.5a 40.3b 0.9

a* 32.1a 28.0b 0.5

b* 24.4a 19.6b 0.5

Hue 37.1a 34.9b 0.3

Means in a row with different subscripts (a-b) are different (P < 0.05)

SSM

DSM

SSM

DSMDay 1 Day 7

(Kim et al., 2010)

LESS EXTENT OF MU-CALPAIN AUTOLYSIS AND PROTEOLYSIS IN DSM

80 kDa

78 kDa

76 kDa

DSM

D 1

SSM

D 1

Intact desmin

Degraded desmin

product

DSM

D 1

SSM

D 1

0

20

40

60

80

100

DSM SSM

Autolyzed calpain (%)

DSM

SSM

0

0.2

0.4

0.6

0.8

1

DSM SSM

Degraded desmin

DSM

SSM

Kim et al. (2010b) Meat Sci. 86: 883-887

µ-Calpain subunits

DSM HAD GREATER STAR PROBE VALUES (TOUGHER) THAN SSM

5.6

5.8

6

6.2

6.4

6.6

6.8

7

7.2

7.4

7.6

D1 D9 D16

x

x

x

y

y

y

Sta

r p

ro

be

(k

g)

Storage and display time

DSM

SSM

xyMeans having different letters within each day are different (p < 0.05).

SEM = 0.31

FAST CHILLING: PARTIAL HOT-BONING?

Implementation of efficient chilling techniques to prevent protein denaturation should improve consistency and quality of fresh beef cuts.

Fast chilling interior portion

(Sammel et al., 2002. JFS)

Hot-boning

INFLUENCE OF STORAGE TEMPERATURE ABUSE ON MEAT COLOR STABILITY

Increase in the storage temperature from the ideal storage temperature of -1.5°C to 2°C significantly decreased the color stability of lamb loins

Long term T abuse: 2°C for 7wks

Short term T abuse: -1.5°C for 6

wks + 1 wk at 2°C.

0 3 5 6 7 8

a* v

alu

e (

re

dn

es

s)

10

12

14

16

18

Control

Long term T abuse

Short term T abuse

(Rosenvold & Wiklund, 2011)

0

5

10

15

20

25

LD PM SM

a*

(re

dn

es

s)

va

lue

3°C

10°C

IMPACT OF ELEVATED DISPLAY TEMPERATURES FOR A SHORT-TIME PERIOD ON MEAT COLOR

(Kim, 2014)

A short-term temperature abuse for 6 hours resulted in about 17% reduction in a* (redness) values of beef muscle

1. TEMPERATURE

I. POST- HARVEST FACTORS

2. AGEING, FREEZING &

THAWING

(Photo from Cryovac Inc.)

MEAT QUALITY CHANGE DURING CHILLED-STORAGE

- Substantial meat quality improvement (tenderness, juiciness and/or flavour) through endogenous enzymatic protein degradation.

Long-term chilled storage during shipping (6 to 8 weeks)

EFFECT OF CHILLING STORAGE PERIODS ON COLOR STABILITY OF LAMB LOINS

Meat color stability decreases with increasing chilling storage periods.

5

7

9

11

13

15

17

19

21

1 2 3 4 5 6 7 8

a* va

lu

e

Display time (Days)

A1wk

A3wk

A9wk

Significant economical issue! $$$

(Kim et al. Unpublished data)

CONVENTIONAL IDEAS ON FRESH VS. FROZEN MEAT

Consumer perception

Meat quality: Fresh (chilled never frozen) > Frozen

EFFECT OF AGEING/FREEZING ON WATER-HOLDING CAPACITY (WHC) OF LAMB LOINS

Ageing/freezing significantly improved WHC of loins

0

2

4

6

8

10

12

A1wk A3wk A9wk A3F6wk F9wk

a

ab

c

c

b

Tota

l lo

ss (

%)

Storage Treatment

Drip loss

Purge loss

abc Different letters indicate significant difference (P < 0.05)

(Kim et al. 2012)

EFFECT OF AGEING/FREEZING ON SHEAR FORCE VALUES OF LAMB LOINS

Ageing-then-freezing significantly improved tenderness of loins

abc Different letters indicate significant difference (P < 0.05)

0

1

2

3

4

5

6

A1wk A3wk A9wk A3F6wk F9wk

a

b

c

bc

a

She

ar f

orc

e (

KgF

)

Storage Treatment

(Kim et al. 2012)

Consumer evaluation of cooked meat after 9 wk storage

Specie / muscle Chilled Aged-frozen Statistical Significance

Preference

Lamb LD 53% 47% NS

Overall acceptability*

Beef

SM 7.1 7.3 NS

LD 7.8 7.1 NS

Venison LD 9.7 9.6 NS

*Unstructured continuous line scale with 0= dislike extremely and 15 = like extremely was used for beef and venison consumer sensory evaluation

(Wiklund et al, 2009; Wiklund et al. 2010)

1

2

3

4

5

6

7

1 2 3 4 5 6 7 8

Dis

colo

rati

on

sco

res

Display days

F9

A2F7

A3F6

A9

EFFECT OF AGED/FROZEN ON COLOUR STABILITY OF LAMB LOINS

Aged/frozen improved color stability of loins during retail display.

(Kim et al. 2013)

1. TEMPERATURE

I. POST- HARVEST FACTORS

2. AGEING, FREEZING &

THAWING

3. PACKAGING

COLOR TRIANGLE

DMb

OMbMMb

Vacuum pack: very stable (weeks)

Oxidation

Overwrap-PVC: short colour life (2-3 days)

HIGH-OXYGEN MODIFIED ATMOSPHERE PACKAGING (HIOX-MAP) SYSTEM

HiOx-MAP (80% O2 + 20% CO2) allows

1) more oxygen to penetrate into meat, consequently forming a higher percentage of oxymyoglobin and a brighter cherry red meat colour

(Photo courtesy of Dr. D.H. Kropf, Kansas State University)

HIGH-OXYGEN MODIFIED ATMOSPHERE PACKAGING (HIOX-MAP) SYSTEM

HiOx-MAP (80% O2 + 20% CO2) allows

1) longer color shelf-life

2) CO2 in the package preventing microbial growth

- High solubility in both muscle and fat tissue- At temp, solubility of CO2, hence is more effective in retarding microbial growth (10 to 14 days).

HIOX-MAP SYSTEM CREATES “OXIDATIVE CONDITIONS”

HiOx-MAP (80% O2 + 20% CO2) are likely to increase the incidence of oxidative changes in the meat, and thus it may negatively affect meat quality characteristics.

EFFECTS OF HIOX-MAP ON MEAT QUALITY

HiOx-MAPVAC

Displayed for 9d at 1°C

Muscle selection: LD, SM, AD (N=10) @ 1 d p.m.

LD SM AD

Trim & cut a steak (2.54 cm)

(Kim et al. 2010)

HiOx MAP VAC

Influence of different packaging types on surface redness

a

b

a

c

a

c

xx

xyy

z yz

abc/xyz Means having different letters are different (p < 0.05).

SEM = 1.11

(Kim et al. 2010)

HiOx MAP VAC

LD

SM

AD

HIOX-MAP INCREASED LIPID OXIDATION OF BEEF STEAKS

HiOx MAP VAC

a

b

a

c

a

d

a a a a a a

abcdMeans with different letters are different (p < 0.05).

SEM = 0.09

(Kim et al. 2010)

HIOX-MAP INCREASED OFF-FLAVOR OF BEEF STEAKS AFTER DISPLAY FOR 9D

Off-flavor

0.1

0.2

0.3

0.4

0.5

MAP VAC

Off-fla

vo

r

a

b

SEM = 0.06

abMeans with different letters are different (p < 0.05).

(Kim et al. 2010)

a

c

c

b

c

c

0

2

4

6

8

10

12

LL SM AD

Sensory Tenderness

MAP

VAC

a

cc

b

cc

0

2

4

6

8

10

LL SM AD

Sensory Chewiness

MAP

VAC

HIOX-MAP DECREASED MEAT TENDERNESS

A. SDS-PAGE

B. Western blot of X-linked MHC

SEM = 0.68

SEM = 0.33

(Kim et al. 2010)

2D-DIAGONAL-PAGE TO DETERMINE ANY INTERMOLECULAR X-LINKED PROTEIN

First dimension SDS-PAGE

VAC MAP

No

n-r

ed

uci

ng

con

dit

ion

VAC MAP

Re

du

cin

g co

nd

itio

n

Re

du

cin

g co

nd

itio

n

Non-reducing condition

Intermolecular disulphide bonds

Second-D SDS-PAGE

HIOX-MAP RESULTED IN PROTEIN POLYMERIZATION

A B

VAC MAP

Cross-linking of MHC with Titin?

Titin Titin

MHCMHC

(Kim et al. 2010)

Premature Browning (PMB):

Mb denatures at a temp. lower than necessary to destroy pathogens (71°C).

HIOX-MAP INDUCES PREMATURE BROWNING

(Photo courtesy of Curwood, Bemis Company Inc.)

(Photo courtesy of Dr. Cornforth, Utah State Univ.)

49°CCould be a major food safety concern!!!

IMPACTS OF HIOX-MAP ON MEAT QUALITY

Color Flavor

Tenderness

Oxidative conditions

Myoglobin oxidation Lipid oxidation

Protein oxidation: protein polymerization formation

Juiciness

Premature browning

THE KEY IS TO PREVENT OXIDATION – O2

DMb

OMbMMbOxidation

1) Different packaging condition(e.g. Ultra LoOX-MAP or CO-MAP)

X

ULTRA LOOX-MAP

- Ultra LoOx-MAP substantiallyminimized an incidence of oxidation during retail display and thus maintained lamb meat quality attributes.

HiOx-MAPLoOx-MAP

- Ultra LoOx-MAP contains 20%CO2/80%N2 with double layers (inside-oxygen permeable; outside –oxygen impermeable)

(Kim et al. 2013)

Lamb loins vacuum-stored for 8 weeks @-1.5°C. Then, either HiOx-MAP or LoOx-MAP displayed for 7 days at 3°C.

0

0.6

1.2

1.8

2.4

HiOx LoOx

TBA

RS

(mg

MD

A/

kg m

eat

)

Day 7

ULTRA LOOX-MAP

1

1.5

2

2.5

3

HiOx LoOx

Aroma

1

1.5

2

2.5

3

HiOx LoOx

Flavour

**P < 0.01

**

**

**

Ultra LoOx-MAP substantially minimized oxidation during retail display time thus improved color/Flavour/Aroma of long-term stored meat.

(Kim et al. 2013)

1: lowest3: highest

CO-MAP

- Consumers perceive CO as a potentially hazardous gas

- A false perception that CO-MAP can mask the discoloration of spoiled meat due to bacterial growth

HiOx-MAP

- CO-MAP contains 0.4%CO/30%CO2/69.6%N2 with oxygen impermeable film.

- FDA approved CO-MAP (0.4%; GRAS for retail packages)

Beef patties packaged in either PVC or CO-MAP (0.4% CO) displayed for 7 days at 2°C.

(Photo courtesy of Dr. Cornforth, Utah State Univ.)

PVC CO-MAP

COMb

(Dr. Cornforth presentation at MIRC, 2007)

Use/Freeze by Date !

MMb

FRESH CASE® SYSTEM –NITRITE CONTAINING FILM

CON NO2

Siegel (2010)

ANOTHER WAY IS TO IMPROVE MRA

DMb

OMbMMb

MRA

Oxidation1) Different packaging condition(e.g. Ultra LoOX-MAP or CO-MAP)

X

2) Injection enhancement

• Commonly used in fresh and processed

meat products with phosphate as an antioxidant – Value added products

(Grousssard et al., 2004)

LACTATE INJECTION ENHANCEMENT

• Lactate ion decreases oxidation by

scavenging free radicals such as

superoxide anion (O2-) and ·OH.

1) Strong antioxidant capacity (Kim et al., 2009)

2) Increased MRA by replenishment of NADH through lactate-LDH coupling reaction (Kim et al., 2006)

LACTATE ENHANCEMENT IMPROVED MEAT COLOR STABILITY

H C

OH

H

C

O

H

OC

H

+ NAD+

Lactate

H C

H

C

O

H

OC

H

+ NADH

Pyruvate

OLDH +H+

MMbDMbMRA

LD

SM

AD

Lactate/PhosphateWater

Lactate/phosphate enhancement decreased lipid oxidation of beef steaks packaged in HiOx-MAP

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

LW LL SW SL AW AL

aa

a a a a

b

a

b

a

b

a

c

a

d

b

d

a

TBA

(m

g m

alo

nal

de

hyd

e/

1 k

g m

eat

)

D1

D9

D16

abcMeans having different letters are different (p < 0.05). (Kim et al. 2010)

Lactate/phosphate enhancement improved tenderness values for LD and SM in HIOX-MAP

a

aa

c

b

a

0

1

2

3

4

5

6

7

LD SM AD

Star

Pro

be

(kg

)

Water Lactate/STP

abcMeans having different letters are different (p < 0.05).

(Kim et al. 2010)

1. FEEDING EFFECT

II. PRE- HARVEST FACTORS

EXPERIMENT SCHEME

Total n= 124

14 week old lambs (n =124) were randomly allocated to 7 different forage treatments for 12 weeks until slaughter:(Clover 12wk, Clover 11wk, Clover 9wk, Lucerne, Chicory, Plantain and Ryegrass)

Paired loins from each carcass stored for 9 weeks @ -1.5°C

Packaged in either HiOx-MAP (80% O2/20% CO2) or LowOx-MAP (20% CO2/80% N2)/displayed for 7 days

-Color stability: Minolta/Sensory color panel-pH-TBARS-Sensory eval.

(Kim et al. 2013)

To test,1) Forage effect2) Packaging effect

EFFECTS OF FORAGE TYPES ON DISCOLORATION OF LONG-TERM CHILLED LOINS DURING DISPLAY UNDER HIOX-MAP

Lucerne

Plantain/Ryegrass

(Kim et al. 2013)

EFFECTS OF FORAGE TYPES ON A* VALUES OF LONG-TERM CHILLED LOINS AFTER 7 D DISPLAY UNDER LOOX-MAP

0

5

10

15

20

25

30

Chicory Control Clover 1 Clover 3 Lucerne Plantain Ryegrass

a* v

alu

es

Before bloom After bloom

Clover 0

Acceptable color was maintained after 7d display under LoOx-MAP

Before bloom

After bloom

HiOx-MAPLoOx-MAP(Kim et al. 2013)

1. FEEDING EFFECT

II. PRE- HARVEST FACTORS

2. GENDER/CASTRATION

Ewe Ram Wether Cryptochid

ANECDOTAL CONCERN

Different gender/castration status influences meat quality attributes ?

Ewe Ram Wether Cryptochid

- Meat from entire (ram) lambs is unsatisfactory?

OBJECTIVES

1) To determine effects of different gender or castration

status on color and lipid oxidation stability of long-term chilled lamb meat

2) To evaluate the influence of different muscle types on color stability of lamb meat during retail display.

(Kim et al. 2014)

LD

Color stability: Ram > Cryptochid > Wether > Ewe

1

2

3

4

5

6

7

1 4 7

Dis

colo

ura

tio

n

Display days

Ewe

Wether

Ram

Cryptorchid

20

25

30

35

40

45

1 4 7

Hu

e a

ngl

e

Display days

Ewe

Wether

Ram

Cryptorchid

(Kim et al. 2014)

EFFECTS OF GENDER/CASTRATION/MUSCLE TYPE ON COLOR STABILITY OF LAMB MUSCLES

20

25

30

35

40

45

50

1 4 7

Hu

e a

ngl

e

Display days

LD

SM

BF

ST

1

2

3

4

5

6

7

1 4 7

Dis

colo

ura

tio

n

Display days

LD

SM

BF

ST

SM

ST

BF(Kim et al. 2014)

EFFECTS OF GENDER/CASTRATION/MUSCLE TYPE ON MYOGLOBIN CONTENTS OF LAMB MEAT

LD

Color stability: ST > LD > BF > SM

EFFECTS OF GENDER/CASTRATION/MUSCLE TYPE ON MYOGLOBIN CONTENTS OF LAMB MEAT

a ab

b b

10

12

14

16

18

20

Ewe Wether Ram Cryptorchid

Myo

glo

bin

co

nte

nts

(mg/

ml)

b

a

b

c

10

15

20

25

LD SM BF ST

Myo

glo

bin

co

nte

nts

(mg/

ml)

SM

ST

BF

LDMyoglobin

- Dark/red- Susceptible to oxidation

(Kim et al. 2014)

a a

a a

c

c

b

b

0

0.5

1

1.5

2

2.5

3

Ewe Wether Ram Cryptorchid

TBA

RS

(mg

MD

A/k

g m

eat

)

Day 1 Day 7

Effects of gender/castration status on lipid oxidation stability of long-term chilled loin during display under

HiOx-MAP

abc Means with different superscripts differ (P <0.05).

Lipid oxidation

&

Discoloration(Myoglobin oxidation)

DMb

OMbMMb

MRA

Oxidation

5. Antioxidant property through feeding strategy(e.g. Ryegrass/Plantain + Se/Vit-E supplementation?)

SUMMARY: IMPLICATION & FURTHER STUDIES?

1. Temperature control(Carcass chilling – Storage – Display)

X

2. Ageing, Freezing & Thawing(Aged/Frozen meat)

3. Developing novel packaging systems

4. Enhancement

6. Animal (breed, gender/castration) & muscle differences

7. Genetically select lambs with high MRA/color stability?

IMPLICATIONS: FUTURE RESEARCH

► Identify fundamental inter-relationship & biochemical mechanism.► Develop innovative methods to control variation in fresh meat quality attributes.

Color Flavor

Tenderness

Myoglobin & lipid oxidation

Myoglobin &

Protein oxidation?

Juiciness

Lipid &

Protein oxidation?

?

• Animal productivity• Genetic influence onmeat quality attributes• Feeding & growth rate effects on muscle fiber type and meat quality• Gender/castration • Animal welfare

•Optimized carcass chilling technology• Pre-rigor hot-boned meat processing• Innovative chilling/freezing/thawing methods• Novel packaging

• Enhancement technology• Modified atmosphere packaging & other innovative packaging methods• Display condition

SUMMARY: STRATEGIES TO IMPROVE MEAT COLOR

Producer Meat Processor Retailer

Colleagues & Mentors

?

?

ACKNOWLEDGEMENTS

• National Cattlemen’s Beef Association

• Iowa Beef Industry Council

• Purac Inc.

• Meat Industry Association, New Zealand

• Ministry of Science and Innovation, New Zealand

• AgResearch CoreFund, New Zealand