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Slice Shear Force
Steven D. Shackelford, Tommy L. Wheeler, and Mohammad Koohmaraie
USDA-ARS U.S. Meat Animal Research Center
History of slice shear force
• Tenderness classification
• Tool for routine measurement of longissimus tenderness
• Potential tool for use on other muscles?
Tenderness classification
Tenderness classification
Carcass chilling
Carcass ribbing Steak removal
Rapid cooking
Rapid shear force
Carcass grading
Carcass sorting
Ribeye blooming(10 minutes)
Develop of a method to automate the process of removing 1 cm diameter cores
from a longissimus steak
Six cores
Develop of a method to automate the process of removing 1 cm diameter cores
from a longissimus steak
• No feasible solution
We concluded that the best we could do was obtain a single slice from each steak.
• The dimensions of that slice would be limited by ribeye size and ….
Fiber angle
Slice shear force
Universal testing machine with 100 kg load cell
Repeatability of slice shear force
0
10
20
30
40
50
60
0 10 20 30 40 50 60
Rep I slice shear force, kg
Rep
II sl
ice
shea
r for
ce, k
g
Repeatability = .87n = 74
Proposed automated system
Manual method for small scale plants
Obtaining 1 cm-thick, 5 cm-long slice
Muscle fiber orientation in slice box
Slice box and double bladed knife
Obtaining 1 cm-thick, 5 cm-long slice
Slice shear force
Overall success = 94.4%, n = 483
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70 75
Day 3 slice shear force, kg
Tender(47%)
100% Tender
Intermediate(48%)
91% Tender
Tough(5%)
28% Tender
Day
14
TSP
tend
erne
ss r
atin
g
Correlation of WBSF and SSF with SPT
1
2
3
4
5
6
7
8
0 1 2 3 4 5 6 7 8
Warner-Bratzler shear force, kg
r = -.77n = 479
r = -.82n = 479
1
2
3
4
5
6
7
8
0 5 10 15 20 25 30 35 40 45 50
Slice shear force, kg
Day
14
TSP
tend
erne
ss r
atin
g
Day
14
TSP
tend
erne
ss r
atin
g
Repeatability of slice shear force for beef
Repeatability = .91n = 110
0
5
10
15
20
25
30
35
40
45
50
55
60
0 5 10 15 20 25 30 35 40 45 50 55 60
Rep I slice shear force, kg
Rep
II sl
ice
shea
r for
ce, k
g
Conversion of SSF to WBSn = 1,518
y = 0.1063x + 2.27R2 = 0.65
0
2
4
6
8
10
12
0 10 20 30 40 50 60 70 80
Slice shear force, kg
War
ner-
Brat
zler
she
ar fo
rce,
kg
Repeatability of slice shear force for lamb
0
10
20
30
40
50
60
70
0 10 20 30 40 50 60 70
Left side longissimus slice shear force, kg
Righ
t sid
e lo
ngis
sim
us sl
ice
shea
r for
ce, k
g
CallipygeNon-callipyge
Repeatability = 0.95n = 87
See the slice
Repeatability of slice shear force for pork
05
10152025303540
0 5 10 15 20 25 30 35 40
Rep A slice shear force, kg
Rep
B s
lice
shea
r for
ce, k
g Repeatability = 0.90n = 744
Mean = 15.3SD = 5.0
NBIAP II
Standardized equipment
•To help insure consistency across institutions
•Available from Gessford Machine Shop, Hastings, NE
Sample sizing box
Slice box and double bladed knife
Slice blade
Papers and protocols available athttp://meats.marc.usda.gov
MOVIE
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