consumers expect high quality meat, which
TRANSCRIPT
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
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
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)
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 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
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
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)
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)
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