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