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Ostrich Slaughter and Fabrication.
Ostrich Slaughter and Fabrication. 2. Carcass Weights, Fabrication Yields, and Muscle Color Evaluation1 C. A. MORRIS,2 S. D. HARRIS, S. G. MAY,3 D. S. HALE, T. C. JACKSON, L. M. LUCIA, R. K. MILLER, J. T. KEETON, G. R. ACUFF, and J. W. SAVELL Department of Animal Science, Texas A&M University, College Station, Texas 77843-2471
1995 Poultry Science 74:1688-1692
INTRODUCTION The ostrich industry is rapidly changing. What once was almost exclusively an industry dominated by the sale of breeding birds is now striving to place ostrich meat on the menus of restaurants across the nation (Morris, 1994). For the ostrich industry to understand the value of live birds, it is necessary that it obtains information on the yield of salable meat from the birds. Currently, no information exists on the slaughter and fabrication yields of ostrich, and specifically, no information exists on the effect of sex on carcass yields. If sex differences do exist, then live birds of one sex may be of greater market value than birds from the other sex based on their expected yields of retail cuts.
The color of fresh meat products offered to the consumer is an important merchandising consideration (Hunt et ah, 1993). In order to characterize the lean meat obtained from ostrich carcasses, an evaluation of the differences in color between muscles and across sexes is necessary. This will provide information to ostrich meat retailers on the expected color of major ostrich retail muscles. The objectives of this study were: 1) to characterize the effect of sex class on the yield of salable lean, fat, bone, and major retail muscles expected from ostrich carcasses; and 2) to determine the effect of sex class and characterize the color of ostrich meat. MATERIALS AND METHODS
Received for publication November 16, 1994. Accepted for publication June 26, 1995. technical article Number 31896 from the Texas Agricultural Experiment Station. 2 To whom correspondence should be addressed. 3 Present address: Westreco, Inc., 3916 Pettis Rd., Missouri Development Center, St. Joseph, MO 64503.
Carcass Fabrication Fourteen ostriches were slaughtered and dressed as described in Morris et dl. (1995) and the carcasses were placed in a cooler at 0 C for 24 h. Chilled carcasses were weighed
1688
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ABSTRACT Seven male and seven female ostrich carcasses were fabricated to determine the effect of sex on the yield of bone, fat, and lean on a weight and carcass percentage basis. The 10 heaviest muscles of the ostrich carcass were removed, weighed, and reported on a carcass percentage basis. Muscle color differences also were determined for 10 selected muscles. Sex did not affect carcass composition or muscle color. Across sexes, ostrich carcasses contained 26.9% bone, 9.2% fat, and 62.5% lean. Of the lean portion, 66.2% was found in the 10 major muscles of leg and thigh. The Gastrocnemius, Iliofibularis, and Fibularis longus were the three largest muscles from the carcass. There were differences (P < .05) in color between ostrich muscles. Muscles of the inside thigh region were the darkest in color and the Iliotibialis cranialis was the brightest, cherry red in color. (Key words: ostrich, meat, carcass composition, meat yield, color)
OSTRICH SLAUGHTER AND FABRICATION
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TABLE 1. The mean weight, SEM, minimum weight, and maximum weight of carcass and caicass side components1 Item
Mean
SEM
54.56 2.35 19.03 1.05 2.61 2.14 1.35 .94
1.55 .07 .46 .03 .07 .06 .15 .03
Minimum -
Cold carcass Neck Semi-boneless leg and thigh Leg bone Bone2 Lean trim2 Fat2 Obturatorius medialis3
14 14 28 28 28 28 28 28
(kg) 43.54 1.90 14.88 .78 2.09 1.45 .32 .54
Maximum 62.60 2.83 24.68 1.43 3.65 2.77 2.93 1.20
With the exception of cold carcass weight and neck weight, the remaining items are excised from a single side. The bone, lean and fat weight presented in this table are the weights of these components that were removed from one side as carcasses were fabricated into major wholesale cuts. 3 This weight is the mean for one untrimmed Obturatorius medialis for that side; there are two on a whole carcass. 2
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
and the neck was removed at the joint muscles (by weight), remaining lean trim, between the last cervical vertebra and first bone and fat. thoracic vertebra. The carcasses then were split down the midline of the back bone Subjective Color Evaluation using a band saw. Ostrich muscle names Following the fabrication of the semiwere identified using the research of Mellett (1994). The Obturatorius tnedialis, a muscle boneless leg and thigh portion, the 10 major along the back, not attached to the leg or muscles were allowed to bloom for an thigh, was removed from the carcass and additional 5 min. Following this bloom weighed, as was the tibia, which was time, color scores from 1 (very dark red) to 8 removed immediately below the two major (bright cherry red) were assigned to each muscles of the lower leg (Gastrocnemius and muscle by trained personnel from Texas Fibularis longus). The seven major leg and A&M University. thigh muscles (Iliotibialis cranialis, Iliofemoralis externus, Iliotibialis lateralis, Iliofibularis,Statistical Analysis Iliofemoralis, Flexor cruris lateralis, and Femorotibialis) were left attached to the The 14 ostriches used in this study were in two replications. The carcasses femur, but were removed from the pelvis processed were analyzed as a randomized block and vertebral column and weighed as a design, blocking by processing day, for the semi-boneless leg and thigh portion. The fat analysis of the effects of sex on fabrication and lean from the vertebral column, ribs, yields and muscle color score by an analysis and wings were removed, and weighed as of variance and characterized using the fat, lean trim, and bone. All carcass fabrica- means procedure of SAS® (SAS Institute, tion yields were calculated on a percentage 1988). Analysis of variance and mean of live weight and of carcass weight basis. separation were obtained using Tukey's The fat, lean trim, O. medialis, and semi- test with a level of significance predeterboneless thigh and leg portion of the carcass mined to be .05 in the General Linear were vacuum-packaged and shipped to Models procedure of SAS® (SAS Institute, Texas A&M University for further dissec- 1988). tion and color evaluation. Upon arriving at the Rosenthal Meat Science and Technology RESULTS AND DISCUSSION Center, the fresh meat products were aged in the vacuum packaged bag for 7 d and then frozen at -10 C. Then, the semi- Carcass Yields boneless leg and thigh portion were thawed Sex did not affect fabrication yields or at 2 C for 24 h and fabricated into nine major muscle color evaluation; therefore, the
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MORRIS ET Ah.
TABLE 2. The mean percentage, SEM, minimum percentage and maximum percentage of the carcass side components,1 calculated on a total carcass weight basis Item
n
Mean
SEM
Neck Semi-boneless leg and thigh weight Leg bone Bone2 Lean trim2 Fat2 Obturatorius medialis
14 28 28 28 28 28 28
4.33 34.86 1.93 4.82 3.94 2.45 1.72
.13 .36 .05 .13 .10 .27 .04
Minimum -
Maximum
(%) 3.71 30.94 1.56 3.59 3.13 .52 1.19
5.63 39.42 2.48 6.20 5.23 5.20 2.10
iPercentage of side components was calculated on a carcass weight basis. Each carcass was divided into two halves down the backbone. Each half is referred to as a side. 2 The bone, lean and fat percentages presented in this table are the percentages of these components that were removed from one side as carcasses were fabricated into major wholesale cuts.
Carcass Composition From the 54.57 kg mean carcass weight, the carcass composition consisted of 62.5% knife separable lean, 9.2% knife separable fat, and 26.9% bone, and 1.4% cutting-drip loss on a carcass weight basis (Tables 3 and 4). These results are similar to those reported for other meat species by Romans et al. (1994) with broiler carcasses averaging 65% lean, turkey carcasses averaging 71% lean, and beef carcasses averaging 64% lean. On a live weight basis, 35.7% of the live ostrich was in the form of lean. Of the total lean separated from an ostrich carcass, approximately two-thirds represents the 10 major muscles and onethird lean trimmings. The majority of the 10 major muscles can be utilized for whole muscle applications (i.e., steaks, roasts, cubes, and stir fry). Within the 10 major muscles, the Gastrocnemius, Iliofibularis, and I. lateralis were the largest muscles from the
TABLE 3. The mean weight, SEM, minimum weight and maximum weight of knife separable fat, lean and bone and of the 10 major muscles as well as the lean trimmings fabricated from the entire ostrich carcass Item
n
Mean
SEM
Minimum
Maximum
43.54 25.90 5.24 11.93 17.41 8.49
62.60 42.09 8.49 16.45 28.36 13.73
flrrl
{"•hi
Cold carcass Total carcass lean1 Total carcass fat Total carcass bone 10 major muscles1 Lean trimming1
14 14 14 14 14 14
54.57 34.11 5.03 14.61 22.59 11.52
.42 .32 .17 .09 .23 .11
^otal lean has been further divided into the 10 major muscle weights and the lean trimming weight.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
populations were pooled and means were reported across sexes. The lack of a sex difference in carcass yields may be due to the fact that the birds in this study were not sexually mature at time of slaughter. Sexually mature ostriches exhibiting secondary sexual characteristics may have yield differences between sexes. The chilled carcass weight, weight and percentage of side components after splitting down the backbone, and the major wholesale cut weights and side percentages are shown in Tables 1 and 2. The neck made up 4.33% of the carcass weight. The O. medialis, which is found along the back bone and referred to in the commercial industry as the tenderloin, represented 1.72% of the total weight of the carcass. The largest portion (34.86%) of the carcass was the semi-boneless leg and thigh portion on the carcass. A majority of the muscle mass in ostrich carcasses is located on the leg and thigh.
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OSTRICH SLAUGHTER AND FABRICATION
TABLE 4. The mean percentage and SEM on a carcass weight and live weight basis of knife separable fat, lean, and bone and of the 10 major muscles as well as lean trimmings fabricated from the entire ostrich carcass Item
n
Mean
SEM
Mean live weight basis
SEM
35.7 5.2 15.3 23.6 12.1
.21 .18 .07 .14 .09
(%\ . Total carcass lean1 Total carcass fat Total carcass bone Ten major muscles 1 Lean trimmings1
14 14 14 14 14
.26 .32 .14 .19 .12
62.5 9.2 26.9 41.4 21.1
•Percentage total lean has been further divided into the percentage 10 major muscles and the percentage lean trimming.
TABLE 5. The mean weight and SEM and the mean percentage on a carcass and live weight basis of the 10 major muscles excised from the ostrich carcass and trimmed free of major connective tissue and fat Muscle
n
Mean weight
Flexor cruris lateralis Iliofemoralis Iliofibularis Iliotibialis cranialis Iliofemoralis externus Iliotibialis lateralis Femorotibialis Obturatorius medialis Gastrocnemius Fibularis longus
14 14 14 14 14 14 14 14 14 14
1.04 .95 3.49 1.41 1.45 3.49 2.09 1.68 4.35 2.59
SEM
Mean live weight basis
Mean carcass weight basis C"\
l\r
.05 .04 .12 .05 .06 .16 .07 .08 .22 .20
1.92 1.71 6.38 2.56 2.69 6.43 3.84 3.12 7.99 4.71
1.10 .98 3.65 1.46 1.53 3.67 2.19 1.78 4.57 2.69
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ostrich carcass, each making up over 6% of ostrich muscles. These muscles may need to the carcass weight (Table 5). The O. medialis be merchandised as separate muscles, as made up 3.12% of the carcass weight. they appear slightly different (either lighter or darker) than other ostrich muscles. Additionally, these muscles may need to be Subjective Color Evaluation segmented from other muscles when furThe mean subjective color scores given ther processing products to reduce variafor each of the 10 ostrich muscles ranged tion in visual appearance of the final from 4.5 to 5.5 on an 8-point scale (Table 6). product. These scores indicate that uncooked ostrich In conclusion, sex did not affect on muscle is slightly dark red to slightly cherry ostrich carcass yields or muscle color evalured in color. Beef is generally described as ation. Therefore, processors of live ostriches being slightly cherry red to moderately should be able to expect similar yields from cherry red in color. Therefore, ostrich meat the carcasses of males and females. Results tends to be darker in color than beef. The I. of this study should provide the rapidly cranialis was the lightest colored muscle and growing ostrich processing industry with it was lighter than the other muscles, except needed information on the salable yield of for the Iliofibularis. The F. cruris lateralis,ostrich meat from carcasses and the exlocated in the inside thigh region, was the pected color of ostrich meat. As the ostrich darkest colored muscle in the ostrich car- industry grows, further research will be cass. The other ostrich muscles did not needed to investigate the influence of differ in lean color. These results indicate nutrition, breed, management, and other that the F. cruris lateralis, Iliofibularis, and I.factors on the composition and quality of cranialis muscles differ in color from other ostrich carcasses.
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MORRIS ET AL.
TABLE 6. Subjective color evaluation1 of the 10 major muscle from the ostrich carcass2 Miscle
Mean color score
SEM
Flexor cruris lateralis Iliofemoralis Iliofibularis Iliotibialis cranialis Iliofemoralis extemus Iliotibialis lateralis Femorotibialis Obturatorius medialis Gastrocnemius Fibularis longus
4.71de 4.44* 5.29b 5.59* 5.21b 4.94"* 5.06bc 4.59"* 5.11bc 5.09bc
.12 .19 .17 .16 .21 .13 .13 .15 .14 .14
a
-*Means with no common superscript are significantly different (P < .05). iSubjective color evaluations were made using a scale from 1 to 8 with 8 representing bright cherry red colored lean and 1 representing a very dark colored lean. 2 n = 14.
The Texas Agricultural Extension Service greatly appreciates the financial support given by the American Ostrich Association for the completion of this project. We also thank H&H Foods, Inc., Mercedes, TX 78570, for the use of its slaughter and fabrication facility throughout this project, and the contributions of Sam Davis and other American Ostrich Association members for their contributions. REFERENCES Hunt, M. C , D. H. Kropf, and J. B. Morgan, 1993. Color measurement of meat and meat products. Pages 59-60 in: Proceedings, 46th Reciprocal
Meat Conference. American Meat Science Association, Chicago, IL. Mellett, F. D., 1994. A note on the musculature of the proximal part of the pelvic limb of the ostrich (Struthio camelus). J. S. Afric. Vet. Assoc. 65(1): 5-9. Morris, C. A, 1994. The birth of an industry. Exclusively Ostrich 2(10):68-73. Morris, C. A., S. D. Harris, T. C. Jackson, S. G. May, D. S. Hale, R. K. Miller, J. T. Keeton, G. R. Acuff, L. M. Lucia, and J. W. Savell, 1995. Ostrich slaughter and fabrication: 1. Slaughter yields, microbiology of carcass and effects of electrical stimulation on post mortem pH. Poultry Sci. 74: 1683-1687. Romans, J. R., W. J. Costello, C. W. Carlson, M. L. Greaser, and K. W. Jones, 1994. The Meat We Eat. Interstate Publishers, Danville, IL. SAS Institute, 1988. SAS/STAT® User's Guide. Release 6.03 Edition. SAS Institute Inc., Cary, NC.
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ACKNOWLEDGMENTS
1995 Poultry Science 74:1688-1692
INTRODUCTION The ostrich industry is rapidly changing. What once was almost exclusively an industry dominated by the sale of breeding birds is now striving to place ostrich meat on the menus of restaurants across the nation (Morris, 1994). For the ostrich industry to understand the value of live birds, it is necessary that it obtains information on the yield of salable meat from the birds. Currently, no information exists on the slaughter and fabrication yields of ostrich, and specifically, no information exists on the effect of sex on carcass yields. If sex differences do exist, then live birds of one sex may be of greater market value than birds from the other sex based on their expected yields of retail cuts.
The color of fresh meat products offered to the consumer is an important merchandising consideration (Hunt et ah, 1993). In order to characterize the lean meat obtained from ostrich carcasses, an evaluation of the differences in color between muscles and across sexes is necessary. This will provide information to ostrich meat retailers on the expected color of major ostrich retail muscles. The objectives of this study were: 1) to characterize the effect of sex class on the yield of salable lean, fat, bone, and major retail muscles expected from ostrich carcasses; and 2) to determine the effect of sex class and characterize the color of ostrich meat. MATERIALS AND METHODS
Received for publication November 16, 1994. Accepted for publication June 26, 1995. technical article Number 31896 from the Texas Agricultural Experiment Station. 2 To whom correspondence should be addressed. 3 Present address: Westreco, Inc., 3916 Pettis Rd., Missouri Development Center, St. Joseph, MO 64503.
Carcass Fabrication Fourteen ostriches were slaughtered and dressed as described in Morris et dl. (1995) and the carcasses were placed in a cooler at 0 C for 24 h. Chilled carcasses were weighed
1688
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
ABSTRACT Seven male and seven female ostrich carcasses were fabricated to determine the effect of sex on the yield of bone, fat, and lean on a weight and carcass percentage basis. The 10 heaviest muscles of the ostrich carcass were removed, weighed, and reported on a carcass percentage basis. Muscle color differences also were determined for 10 selected muscles. Sex did not affect carcass composition or muscle color. Across sexes, ostrich carcasses contained 26.9% bone, 9.2% fat, and 62.5% lean. Of the lean portion, 66.2% was found in the 10 major muscles of leg and thigh. The Gastrocnemius, Iliofibularis, and Fibularis longus were the three largest muscles from the carcass. There were differences (P < .05) in color between ostrich muscles. Muscles of the inside thigh region were the darkest in color and the Iliotibialis cranialis was the brightest, cherry red in color. (Key words: ostrich, meat, carcass composition, meat yield, color)
OSTRICH SLAUGHTER AND FABRICATION
1689
TABLE 1. The mean weight, SEM, minimum weight, and maximum weight of carcass and caicass side components1 Item
Mean
SEM
54.56 2.35 19.03 1.05 2.61 2.14 1.35 .94
1.55 .07 .46 .03 .07 .06 .15 .03
Minimum -
Cold carcass Neck Semi-boneless leg and thigh Leg bone Bone2 Lean trim2 Fat2 Obturatorius medialis3
14 14 28 28 28 28 28 28
(kg) 43.54 1.90 14.88 .78 2.09 1.45 .32 .54
Maximum 62.60 2.83 24.68 1.43 3.65 2.77 2.93 1.20
With the exception of cold carcass weight and neck weight, the remaining items are excised from a single side. The bone, lean and fat weight presented in this table are the weights of these components that were removed from one side as carcasses were fabricated into major wholesale cuts. 3 This weight is the mean for one untrimmed Obturatorius medialis for that side; there are two on a whole carcass. 2
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
and the neck was removed at the joint muscles (by weight), remaining lean trim, between the last cervical vertebra and first bone and fat. thoracic vertebra. The carcasses then were split down the midline of the back bone Subjective Color Evaluation using a band saw. Ostrich muscle names Following the fabrication of the semiwere identified using the research of Mellett (1994). The Obturatorius tnedialis, a muscle boneless leg and thigh portion, the 10 major along the back, not attached to the leg or muscles were allowed to bloom for an thigh, was removed from the carcass and additional 5 min. Following this bloom weighed, as was the tibia, which was time, color scores from 1 (very dark red) to 8 removed immediately below the two major (bright cherry red) were assigned to each muscles of the lower leg (Gastrocnemius and muscle by trained personnel from Texas Fibularis longus). The seven major leg and A&M University. thigh muscles (Iliotibialis cranialis, Iliofemoralis externus, Iliotibialis lateralis, Iliofibularis,Statistical Analysis Iliofemoralis, Flexor cruris lateralis, and Femorotibialis) were left attached to the The 14 ostriches used in this study were in two replications. The carcasses femur, but were removed from the pelvis processed were analyzed as a randomized block and vertebral column and weighed as a design, blocking by processing day, for the semi-boneless leg and thigh portion. The fat analysis of the effects of sex on fabrication and lean from the vertebral column, ribs, yields and muscle color score by an analysis and wings were removed, and weighed as of variance and characterized using the fat, lean trim, and bone. All carcass fabrica- means procedure of SAS® (SAS Institute, tion yields were calculated on a percentage 1988). Analysis of variance and mean of live weight and of carcass weight basis. separation were obtained using Tukey's The fat, lean trim, O. medialis, and semi- test with a level of significance predeterboneless thigh and leg portion of the carcass mined to be .05 in the General Linear were vacuum-packaged and shipped to Models procedure of SAS® (SAS Institute, Texas A&M University for further dissec- 1988). tion and color evaluation. Upon arriving at the Rosenthal Meat Science and Technology RESULTS AND DISCUSSION Center, the fresh meat products were aged in the vacuum packaged bag for 7 d and then frozen at -10 C. Then, the semi- Carcass Yields boneless leg and thigh portion were thawed Sex did not affect fabrication yields or at 2 C for 24 h and fabricated into nine major muscle color evaluation; therefore, the
1690
MORRIS ET Ah.
TABLE 2. The mean percentage, SEM, minimum percentage and maximum percentage of the carcass side components,1 calculated on a total carcass weight basis Item
n
Mean
SEM
Neck Semi-boneless leg and thigh weight Leg bone Bone2 Lean trim2 Fat2 Obturatorius medialis
14 28 28 28 28 28 28
4.33 34.86 1.93 4.82 3.94 2.45 1.72
.13 .36 .05 .13 .10 .27 .04
Minimum -
Maximum
(%) 3.71 30.94 1.56 3.59 3.13 .52 1.19
5.63 39.42 2.48 6.20 5.23 5.20 2.10
iPercentage of side components was calculated on a carcass weight basis. Each carcass was divided into two halves down the backbone. Each half is referred to as a side. 2 The bone, lean and fat percentages presented in this table are the percentages of these components that were removed from one side as carcasses were fabricated into major wholesale cuts.
Carcass Composition From the 54.57 kg mean carcass weight, the carcass composition consisted of 62.5% knife separable lean, 9.2% knife separable fat, and 26.9% bone, and 1.4% cutting-drip loss on a carcass weight basis (Tables 3 and 4). These results are similar to those reported for other meat species by Romans et al. (1994) with broiler carcasses averaging 65% lean, turkey carcasses averaging 71% lean, and beef carcasses averaging 64% lean. On a live weight basis, 35.7% of the live ostrich was in the form of lean. Of the total lean separated from an ostrich carcass, approximately two-thirds represents the 10 major muscles and onethird lean trimmings. The majority of the 10 major muscles can be utilized for whole muscle applications (i.e., steaks, roasts, cubes, and stir fry). Within the 10 major muscles, the Gastrocnemius, Iliofibularis, and I. lateralis were the largest muscles from the
TABLE 3. The mean weight, SEM, minimum weight and maximum weight of knife separable fat, lean and bone and of the 10 major muscles as well as the lean trimmings fabricated from the entire ostrich carcass Item
n
Mean
SEM
Minimum
Maximum
43.54 25.90 5.24 11.93 17.41 8.49
62.60 42.09 8.49 16.45 28.36 13.73
flrrl
{"•hi
Cold carcass Total carcass lean1 Total carcass fat Total carcass bone 10 major muscles1 Lean trimming1
14 14 14 14 14 14
54.57 34.11 5.03 14.61 22.59 11.52
.42 .32 .17 .09 .23 .11
^otal lean has been further divided into the 10 major muscle weights and the lean trimming weight.
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
populations were pooled and means were reported across sexes. The lack of a sex difference in carcass yields may be due to the fact that the birds in this study were not sexually mature at time of slaughter. Sexually mature ostriches exhibiting secondary sexual characteristics may have yield differences between sexes. The chilled carcass weight, weight and percentage of side components after splitting down the backbone, and the major wholesale cut weights and side percentages are shown in Tables 1 and 2. The neck made up 4.33% of the carcass weight. The O. medialis, which is found along the back bone and referred to in the commercial industry as the tenderloin, represented 1.72% of the total weight of the carcass. The largest portion (34.86%) of the carcass was the semi-boneless leg and thigh portion on the carcass. A majority of the muscle mass in ostrich carcasses is located on the leg and thigh.
1691
OSTRICH SLAUGHTER AND FABRICATION
TABLE 4. The mean percentage and SEM on a carcass weight and live weight basis of knife separable fat, lean, and bone and of the 10 major muscles as well as lean trimmings fabricated from the entire ostrich carcass Item
n
Mean
SEM
Mean live weight basis
SEM
35.7 5.2 15.3 23.6 12.1
.21 .18 .07 .14 .09
(%\ . Total carcass lean1 Total carcass fat Total carcass bone Ten major muscles 1 Lean trimmings1
14 14 14 14 14
.26 .32 .14 .19 .12
62.5 9.2 26.9 41.4 21.1
•Percentage total lean has been further divided into the percentage 10 major muscles and the percentage lean trimming.
TABLE 5. The mean weight and SEM and the mean percentage on a carcass and live weight basis of the 10 major muscles excised from the ostrich carcass and trimmed free of major connective tissue and fat Muscle
n
Mean weight
Flexor cruris lateralis Iliofemoralis Iliofibularis Iliotibialis cranialis Iliofemoralis externus Iliotibialis lateralis Femorotibialis Obturatorius medialis Gastrocnemius Fibularis longus
14 14 14 14 14 14 14 14 14 14
1.04 .95 3.49 1.41 1.45 3.49 2.09 1.68 4.35 2.59
SEM
Mean live weight basis
Mean carcass weight basis C"\
l\r
.05 .04 .12 .05 .06 .16 .07 .08 .22 .20
1.92 1.71 6.38 2.56 2.69 6.43 3.84 3.12 7.99 4.71
1.10 .98 3.65 1.46 1.53 3.67 2.19 1.78 4.57 2.69
Downloaded from http://ps.oxfordjournals.org/ at :: on January 24, 2015
ostrich carcass, each making up over 6% of ostrich muscles. These muscles may need to the carcass weight (Table 5). The O. medialis be merchandised as separate muscles, as made up 3.12% of the carcass weight. they appear slightly different (either lighter or darker) than other ostrich muscles. Additionally, these muscles may need to be Subjective Color Evaluation segmented from other muscles when furThe mean subjective color scores given ther processing products to reduce variafor each of the 10 ostrich muscles ranged tion in visual appearance of the final from 4.5 to 5.5 on an 8-point scale (Table 6). product. These scores indicate that uncooked ostrich In conclusion, sex did not affect on muscle is slightly dark red to slightly cherry ostrich carcass yields or muscle color evalured in color. Beef is generally described as ation. Therefore, processors of live ostriches being slightly cherry red to moderately should be able to expect similar yields from cherry red in color. Therefore, ostrich meat the carcasses of males and females. Results tends to be darker in color than beef. The I. of this study should provide the rapidly cranialis was the lightest colored muscle and growing ostrich processing industry with it was lighter than the other muscles, except needed information on the salable yield of for the Iliofibularis. The F. cruris lateralis,ostrich meat from carcasses and the exlocated in the inside thigh region, was the pected color of ostrich meat. As the ostrich darkest colored muscle in the ostrich car- industry grows, further research will be cass. The other ostrich muscles did not needed to investigate the influence of differ in lean color. These results indicate nutrition, breed, management, and other that the F. cruris lateralis, Iliofibularis, and I.factors on the composition and quality of cranialis muscles differ in color from other ostrich carcasses.
1692
MORRIS ET AL.
TABLE 6. Subjective color evaluation1 of the 10 major muscle from the ostrich carcass2 Miscle
Mean color score
SEM
Flexor cruris lateralis Iliofemoralis Iliofibularis Iliotibialis cranialis Iliofemoralis extemus Iliotibialis lateralis Femorotibialis Obturatorius medialis Gastrocnemius Fibularis longus
4.71de 4.44* 5.29b 5.59* 5.21b 4.94"* 5.06bc 4.59"* 5.11bc 5.09bc
.12 .19 .17 .16 .21 .13 .13 .15 .14 .14
a
-*Means with no common superscript are significantly different (P < .05). iSubjective color evaluations were made using a scale from 1 to 8 with 8 representing bright cherry red colored lean and 1 representing a very dark colored lean. 2 n = 14.
The Texas Agricultural Extension Service greatly appreciates the financial support given by the American Ostrich Association for the completion of this project. We also thank H&H Foods, Inc., Mercedes, TX 78570, for the use of its slaughter and fabrication facility throughout this project, and the contributions of Sam Davis and other American Ostrich Association members for their contributions. REFERENCES Hunt, M. C , D. H. Kropf, and J. B. Morgan, 1993. Color measurement of meat and meat products. Pages 59-60 in: Proceedings, 46th Reciprocal
Meat Conference. American Meat Science Association, Chicago, IL. Mellett, F. D., 1994. A note on the musculature of the proximal part of the pelvic limb of the ostrich (Struthio camelus). J. S. Afric. Vet. Assoc. 65(1): 5-9. Morris, C. A, 1994. The birth of an industry. Exclusively Ostrich 2(10):68-73. Morris, C. A., S. D. Harris, T. C. Jackson, S. G. May, D. S. Hale, R. K. Miller, J. T. Keeton, G. R. Acuff, L. M. Lucia, and J. W. Savell, 1995. Ostrich slaughter and fabrication: 1. Slaughter yields, microbiology of carcass and effects of electrical stimulation on post mortem pH. Poultry Sci. 74: 1683-1687. Romans, J. R., W. J. Costello, C. W. Carlson, M. L. Greaser, and K. W. Jones, 1994. The Meat We Eat. Interstate Publishers, Danville, IL. SAS Institute, 1988. SAS/STAT® User's Guide. Release 6.03 Edition. SAS Institute Inc., Cary, NC.
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ACKNOWLEDGMENTS