Effect of Dietary Sorghum Cultivars on the Storage Stability
of Broiler Breast and Thigh Meat1
M. Du,* G. Cherian,† P. A. Stitt,‡ and D. U. Ahn*,2
*Department of Animal Science, Iowa State University, Ames, Iowa 50011; †Department of Animal Science,
Oregon State University, Corvallis, Oregon 97331-6702; and
‡Essential Nutrient Research Corp. Manitowoc, Wisconsin 54221-0730
ABSTRACT A total of 450 1-d-old male broiler chicks
were fed a corn-soy-flax meal-based diet (control), two
cultivars of sorghum—Ruby Red (low tannin content)
and Valpo Red (high tannin content)—were used at 10%
level. Birds were slaughtered at the end of 42-d feeding
trial. Boneless, skinless breast and thigh muscles were
separated and ground to make patties. Half of the breast
and thigh meat patties were individually packaged in
zipper bags, and 2-TBA-reactive substances (TBARS) and
colors of the patties were determined after 0 and 7 d of
storage at 4 C. The other half was cooked and vacuumpackaged. The vacuum-packaged patties were used to
determine time-dependent volatile production and oxida-
tive change during 12-h holding time before analyses.
Thigh meat from broilers fed the Valpo Red cultivar produced lower TBARS than that from control at Day 0. The
amounts of aldehydes and sulfur compounds of cooked
breast meats were lower from chickens fed the Valpo Red
cultivar than those fed the control or Ruby Red cultivar.
Dietary Valpo Red cultivar improved the oxidative stability of breast meat 8 and 12 h after cooking. Dietary sorghum slightly improved the color a* stability of raw thigh
meat patties. This result indicated that feeding sorghum
to broilers could improve some measures of the storage
stability of broiler meat, but sorghum with high tannin
content was more effective than that with low tannin
content.
(Key words: sorghum, boiler meat, storage stability, volatiles, color)
2002 Poultry Science 81:1385–1391
INTRODUCTION
Broiler diets can influence the oxidative stability of meat.
Dietary vitamin E has been used to improve the oxidative
stability of meat (Maraschiello et al., 1999). Garlic supplement (at 50g/kg of feed) is effective in improving oxidative
stability of cooked chicken breast and thigh meats (Abdalla, 1999). Cave and Burrows (1993) reported that increasing naked oat in chicken diets decreases the oxidation
in chicken thigh meat.
Sorghum contains high levels of tannin and other phenolic compounds (El-Khalifa and El-Tinay, 1994). Tannin and
related phenolic compounds have strong antioxidant effects. Yokozawa et al. (2000) reported that green tea extract
and tannin mixtures protected cultured cells from oxidative stress, and tannin mixtures exhibit higher antioxidant
activity than green tea extracts. Yokozawa et al. (2000) fed
rats diets with tannin and found that lipid peroxidation
2002 Poultry Science Association, Inc.
Received for publication July 30, 2001.
Accepted for publication April 10, 2002.
1
Journal Paper Number J-19469 of the Iowa Agriculture and Home
Economics Experiment Station, Ames, IA 50011-3150. Project Number
3706; supported by the Hatch Act and Essential Nutrient Research Corp.
2
To whom correspondence should be addressed: duahn@iastate.edu.
in plasma and tissues decreased significantly in the presence of supplemented polymeric tannins. They also found
that the antioxidant effect of tannin was as effective as that
of vitamin E. By using radioactive 14C tracing, Jimenez et
al. (1994) analyzed the absorption of condensed tannin and
other phenolic compounds and suggested that radiolabeled condensed tannins from sorghum grain are not absorbed from the digestive tract of chickens, but nontannin
phenolic compounds are absorbed and distributed in various tissues. This finding suggests that the absorbed phenolic compounds present in muscle could exhibit antioxidant
effects and, thus, improve the oxidative stability of meat.
The 2-TBA-reactive substances (TBARS) test measures
malonaldhyde content in meat and is the most frequently
used test to determine lipid oxidation. TBARS is positively
related to warmed-over flavor and hexanal content in meat
(Igene et al., 1985; Shu et al., 1995). The propanal, pentanal,
hexanal, and total volatiles were also highly correlated
with the TBARS values of meat (Ahn et al., 1998). Cooked
meats are highly susceptible to oxidative changes upon
exposure to air. Ahn et al. (1999a) showed that minced
meat samples are quickly oxidized in sample vials during
holding time for volatile analysis. The TBARS and hexanal
1385
Abbreviation Key: TBARS = 2-TBA-reactive substances.
1386
DU ET AL.
production of meat samples increase linearly with the duration of sample holding time, and their production rates
differ depending on the susceptibility of meat samples to
oxidation (Ahn et al., 1999b). Thus, this time-dependent
volatile production on oxidative changes during sample
holding provides a simple and quick model for assessing
the oxidative stability of meat and was used in the current
study for analyzing the oxidative stability of cooked broiler
chicken meats.
Lipid oxidation is also related to color stability. Greene
(1969) first reported that lipid oxidation and metmyoglobin
formation is well correlated. The rate of discoloration is
closely related to the rate of myoglobin oxidation induced
by lipid oxidation (Yin and Faustman, 1993). Schaefer et
al. (1995) hypothesized that the products of lipid oxidation
are more water-soluble than their parent compounds and
can enter the cytoplasm where they interact with myoglobin to hasten its oxidation. Sorghum feeding may improve
the color stability of meat by its antioxidant effects. The
objective of the study reported here was to determine the
effect of dietary sorghum on the oxidative stability of raw
and cooked broiler chicken meats.
MATERIALS AND METHODS
Sample Preparation
Day-old male Hubbard broiler chicks were obtained
from a commercial hatchery and divided among nine pens
(50 birds/pen). Three pens each were assigned to a diet
containing 10% Ruby Red sorghum cultivar (high tannin
content), 10% Valpo Red (low tannin content), or control
(corn-soy basal diet) and were fed for 42 d. The diets were
formulated to contain 21.5% crude protein and 3,050 kcal
of energy/kg of diet. Four birds from each pen were randomly selected and slaughtered according to the USDA
guidelines. Birds were killed by exsanguination, bled for
90 s, scalded at 54 C for 120 s, and mechanically defeathered
for 30 s. Feet were removed manually by severing the
intratarsal joint. Carcasses were manually eviscerated,
washed, and allowed to drip for 5 min. Carcasses were
chilled in ice slush for 30 min, allowed to drip for 5 min,
and then stored overnight at 4 C. Breast and leg meats
were separated from the selected carcasses, and the meats
of four birds from the same pen were pooled and used as
a replicate. After removing skin and visible fats, breast
and thigh meats were ground separately through 9- and
3-mm plates. The ground breast and thigh meats were
made into 100-g patties. Half of each patty was individually packaged an aerobic bag, stored at 4 C, and analyzed
at 0 and 7 d for TBARS and color. The other half was
vacuum-packaged and cooked in a 90 C water bath to an
internal temperature of 74 C, drained, and then repackaged
3
Koch, Kansas City, MO.
Tekmar-Dohrmann, Cincinnati, OH.
5
Hewlett-Packard Co. Wilmington, DE.
6
Hunter Associated Labs Inc., Reston, VA.
immediately in oxygen impermeable bags3 (nylon/polyethylene, 9.3 mL O2/m2/24 h at 0 C) and used for volatiles
and TBARS measurements within 3 d of cooking.
Volatile Compound Analyses
A purge-and-trap apparatus4 (Precept II and purge-andtrap 3000) connected to a gas chromatograph/mass spectrometer5 (GC/MS) was used to analyze volatiles. One
gram of cooked meat patties was added into 40-mL sample
vials, flushed with 99.99% helium for 5 s at 40 psi, and
held for 0, 4, 8, or 12 h at 4 C before volatile analyses. The
meat samples were purged with helium gas (40 mL/min)
for 15 min. Volatiles were trapped at 20 C using a Tenax
column,4 desorbed for 2 min at 220 C, focused in a cryofocusing unit4 at −90 C, and then thermally desorbed onto
a column for 30 s at 220 C. A combined column (8-m HP624 column,5 250-µm i.d. with 1.4-µm nominal; a 52-m HP1 column,5 250-µm i.d. with 0.25 µm nominal; and an 8m HP-wax column5 250-µm i.d. with 0.25-µm nominal
combined using zero dead-volume column connectors)
was used for volatile analysis. The oven temperature was
kept at 0 C for 2.5 min, increased to 10 C at 2.5 C/min,
increased to 45 C at 10 C/min, increased to 110 C at 20
C/min, increased to 180 C at 10 C/min, and held for 4.5
min. This procedure was used to improve volatile separation. Inlet temperature of the gas chromatograph oven
was 180 C. Liquid nitrogen was used to cool oven below
ambient temperature. Helium was the carrier gas at constant pressure of 20.5 psi. The ionization potential of the
mass spectrometer was 70 eV, and scan range was 18.1
to 300 m/z. Identification of volatiles was achieved by
comparing mass spectral data of samples with those of the
Wiley Library6 and standards when available. The area of
each peak was integrated using the ChemStation software,5
and the total peak area (pA × s) × 104 was reported as an
indicator of volatiles generated from meat samples. The
peaks produced by mass spectral data were grouped into
five major volatile classes (alkanes, alkenes, ketones, aldehydes, and sulfur-containing compounds) and are reported.
Color Measurement
The color was determined on the packaged surface of
meat samples using a Labscan Hunter color meter6 that
had been calibrated against white and black reference tiles
packaged in the same bags as those used for meat packaging. Hunter values were obtained for L* (lightness), a*
(redness), and b* (yellowness) (American Meat Science
Association, 1991) using a setting of D65 (daylight, 65degree light angle). An average value from two random
locations on each sample surface was used for statistical
analysis.
TBARS Analyses
4
For the raw meat, 3 g of meat was weighed into a 50mL test tube and homogenized with 15 mL of deionized
1387
DIETARY SORGHUM ON THE STABILITY OF BROILER MEAT
TABLE 1. The 2-TBA-reactive substances (TBARS) values after storage (0 or 7 d) of raw broiler breast
and thigh meat from birds fed a control diet or sorghum
Dietary
treatment
Breast meat
0d
Thigh meat
7d
SEM
0d
7d
SEM
2.04a
1.82a
1.43a
0.21
0.15
0.22
0.06
1
TBARS (mg MDA /kg meat)
Control
Ruby Red
Valpo Red
SEM
0.70
0.82
0.66
0.06
1.10
0.95
0.99
0.14
0.13
0.09
0.10
1.26b,x
1.03b,x,y
0.83b,y
0.08
Different letters within a row of the same category differed significantly (P < 0.05); n = 3.
Different letters within a column differed significantly (P < 0.05).
1
MDA = malondialdehyde.
a,b
x-z
distilled water (DDW) using a Polytron homogenizer7
(Type PT 10/35) for 10 s at highest speed. One milliliter
of the meat homogenate was transferred to a disposable
test tube (3 × 100 mm), and butylated hydroxyanisole (50
µL, 7.2%) and TBA-trichloroacetic acid (TCA) (2 mL) were
added. The mixture was vortexed and then incubated in
a boiling water bath for 15 min to develop color. The
sample was then cooled in cold water for 10 min, vortexed
again, and centrifuged for 15 min at 2,000 × g. The absorbance of the resulting supernatant solution was determined at 531 nm against a blank containing 1 mL of DDW
and 2 mL of TBA-TCA solution. For cooked meat, TBARS
was analyzed at the same interval as in volatile analyses
(every 4 h). If the absorbance of the solution after color
development was greater than 1, the solution was diluted
properly with water and TBA-TCA mixture (1:2) until the
absorbance was less than 1.0. The amounts of TBARS were
expressed as milligrams of malondialdehyde per kilogram
of meat.
Statistical Analyses
The effect of dietary sorghum on the volatiles, TBARS,
and color of chicken breast and thigh meat were analyzed
statistically using the general linear models procedure of
SAS software (SAS Institute, 1989). Student-NewmanKeuls’ multiple-range test was used to compare differences
among mean values (P < 0.05). Means and SEM are reported. The interactions between sorghum treatments and
storage for volatiles were also analyzed by general linear models.
RESULTS AND DISCUSSION
Table 1 shows the TBARS values of raw broiler chicken
breast and thigh meat after 0 and 7 d of storage under
aerobic conditions. The TBARS values of raw thigh meat
from broilers fed the Valpo Red sorghum were lower than
those fed the control diet at 0 d of storage but not 7 d
of storage. The TBARS indicated that dietary Valpo Red
cultivar sorghum slightly improved the oxidative stability
7
Brinkman Instruments Inc., Westbury, NY.
of raw thigh meat. The ineffectiveness of dietary Valpo Red
cultivar sorghum in improving raw breast meat oxidative
stability could be due to few oxidative changes occurring
in the breast meat, which could have masked the treatment
effect. The stronger antioxidant effect of Valpo Red compared with Ruby Red could be due to its higher tannin
content than Ruby Red cultivar. Yokozawa et al. (1998)
suggested that dietary tannin had a protective action
against oxidative stress in rats. A recent report indicated
that specific polyphenols play a role as antioxidants inhibiting lipid peroxidation, low-density lipoprotein oxidation,
and scavenging oxygen radicals (Sanchez et al., 2000). Tannin, like other polyphenols, is an effective reducing agent
and may prevent diseases related to oxidative stress (Santos and Scalbert, 2000).
There were no differences in L* and b* values of raw
broiler meats by dietary sorghum treatments and storage
(Table 2). At 0 d of storage, no difference in a* values was
observed for raw breast and thigh meats among treatments. After 7 d of storage, the a* value of raw thigh meat
from broilers fed with sorghum was higher than that of
broilers on the control diet. The a* value of raw thigh meat
from control broilers decreased significantly after 7 d of
storage, but no significant reduction was observed for the
meats from the sorghum treatments.
Smaller changes in color a* for dietary sorghum than
for control indicated that the color stability of raw thigh
meat during storage was improved by the dietary sorghum. After 7 d of storage, however, there was a significant
reduction in the a* value of raw breast meat from broilers
fed Ruby Red. The reason for this reduction is not clear.
Due to the structural damage to phospholipids during
cooking, cooked meats tend to become oxidized and easily
generate warmed-over flavor upon exposure to air (Ahn
et al., 1992). Table 3 shows the TBARS of cooked meats at
different durations of holding. At 0 h of holding, dietary
sorghum reduced the TBARS of cooked breast meat. In
cooked thigh meat, however, the TBARS of meat from
broilers fed Valpo Red cultivar was higher than that of
the control and Ruby Red. This result was somewhat unexpected. One possible reason for this finding could be that
the phenolic compounds or tannins in thigh meat kept the
iron in reduced state, which exhibited stronger prooxidative effects than ferric iron. Also, thigh meat is higher in
iron content than breast meat, which could be another
1388
DU ET AL.
TABLE 2. Color values after storage (0 or 7 d) of raw broiler breast and thigh meat
from birds fed a control diet or sorghum
Breast meat
L* value
0d
7d
SEM
a* value
0d
7d
SEM
b* value
0d
3d
SEM
Thigh meat
Control
Ruby Red
Valpo Red
SEM
Control
Ruby Red
Valpo Red
SEM
49.88
50.77
0.94
51.38
52.73
1.31
51.71
50.66
0.72
0.72
1.24
50.83
53.30
1.08
52.10
53.14
0.79
52.15
51.43
0.90
0.87
0.98
4.70
4.06
0.26
4.62x
3.55y
0.27
4.63
4.08
0.33
0.30
0.27
11.08x
9.13b,y
0.34
12.47
11.09a
0.48
11.28
10.82a
0.66
0.52
0.50
9.83
9.65
0.32
9.28
8.75
0.47
9.38
9.38
0.32
0.38
0.38
14.76
16.07
0.58
16.23
16.61
0.57
15.21
15.92
0.53
0.62
0.49
Different letters within a row of the same category differed significantly (P < 0.05); n = 3.
Different letters within a column of the same category differed significantly (P < 0.05).
a,b
x,y
reason for the difference in the antioxidant effect of sorghum between cooked breast and thigh meat. Ahn and
Kim (1998) showed that reduced iron is a potent prooxidant. Cooked breast meats from sorghum treatments maintained lower TBARS than controls at 8 and 12 h of holding,
showing the effectiveness of sorghum in improving the
oxidative stability. For cooked thigh meat, the sorghum
treatments were not effective in reducing TBARS values.
The production of volatiles is closely related to the oxidative changes in meat. Table 4 shows that the volatile profiles of cooked breast meat at different durations of holding. The volatiles were grouped into aldehydes, alkanes,
alkenes, ketones, and sulfur compounds and are reported.
The amount of aldehydes was consistently the highest in
control meat, followed by Ruby Red; Valpo Red had the
least aldehydes (Table 4). The production of aldehydes is
closely related to the oxidation of meat (Ahn et al., 1999a,b).
This difference showed that the Valpo Red cultivar improved the oxidative stability of cooked breast meat, the
but Ruby Red cultivar was less effective in improving
oxidative stability.
Among the aldehydes, hexanal, and pentanal increased
greatly and contributed the majority of increment in alde-
hydes during holding, and the increase of pentanal in
breast meat from Valpo Red treatment was less than that
of Ruby Red and control (Table 5). Pentane was the main
alkanes detected, followed by heptane, octane, and hexane.
After 12 h of holding, productions of pentane and heptane
from cooked broiler meats of Valpo Red cultivar treatment
were significantly lower than those from control (Table 5),
as were total alkanes and alkenes after 4 h of holding
(Table 4). This finding indicated that cooked breast meats
from broilers fed Valpo Red cultivar had higher oxidative
stability than those fed the control diet.
The amounts of sulfur compound in cooked breast meat
were also reduced by dietary sorghum treatments. Cooked
breast meat from broilers fed Valpo Red produced significantly less sulfur compounds than those on control and
Ruby Red treatments. Dimethyl disulfide was the main
sulfur compounds in cooked broiler breast meat and increased greatly with sample holding time (Table 5). 2Propanone was the major ketone detected, but the amounts
of 2-propanone and total ketones were not changed significantly by dietary treatment and sample holding time.
Dietary sorghum also influenced the volatiles of cooked
thigh meat (Table 6). Dietary sorghum treatments had no
TABLE 3. The 2-TBA-reactive substances (TBARS) after different durations of holding (0 to 12 h) of
cooked broiler breast and thigh meat patties from birds fed a control diet or sorghum
Dietary treatment
0h
4h
8h
12 h
SEM
8.79a,x
7.78a,y
6.56a,z
0.184
0.153
0.239
0.144
TBARS (mg MDA1/kg meat)
Breast meat
Control
Ruby Red
Valpo Red
SEM
Thigh meat
Control
Ruby Red
Valpo Red
SEM
1.69c,x
1.02d,y
1.01d,y
0.106
2.15c
2.49c
2.29c
0.262
6.49b,x
4.26b,y
3.78b,z
0.147
1.54d,y
1.77d,y
2.08d,x
0.088
5.83c,y
6.60c,x
6.76c,x
0.178
8.30b,y
9.99b,x
8.77b,y
0.208
13.69a
13.68a
14.09a
0.180
Different letters within a row differed significantly (P < 0.05); n = 3.
Different letters within a column of the same category differed significantly (P < 0.05).
1
MDA = malondialdehyde.
a-d
x-z
0.167
0.135
0.200
1389
DIETARY SORGHUM ON THE STABILITY OF BROILER MEAT
TABLE 4. Volatile profiles after different durations of holding (0 to 12 h) of cooked broiler breast
from birds fed a control diet or sorghum
Volatile1
0h
4h
8h
12 h
SEM
(total ion counts × 10 )
4
Aldehydes
Control
Ruby Red
Valpo Red
SEM
Alkanes
Control
Ruby Red
Valpo Red
SEM
Alkenes
Control
Ruby Red
Valpo Red
SEM
Ketones
Control
Ruby Red
Valpo Red
SEM
Sulfur compounds
Control
Ruby Red
Valpo Red
SEM
59,298d,x
50,941d,x
32,473d,y
5,029
154,438c,x
130,327c,y
89,810c,z
4,317
285,241b,x
244,734b,y
193,533b,z
12,302
358,708a,x
349,656a,x
282,449a,y
10,628
10,325
9,410
5,384
17,698c
14,498c
11,808c
2,033
47,137b,x
42,908b,x
32,300b,y
1,684
59,481a
58,673a
49,182a
2,721
65,214a
59,329a
52,700a
3,616
2,449
3,221
2,053
5,260a
5,474a
4,207a
608
5,898a
5,603a
4,830a
362
437
444
304
5,619
3,147
3,572
1,061c
625c
670c
125
3,635b,x
2,695b,xy
1,945b,y
358
62,821
75,718
64,313
4,890
61,714
76,568
68,696
4,978
77,495
84,480
75,929
3,268
78,270
87,085
75,767
3,603
9,546b
10,726b
9,436b
1,048
15,616a,x
15,172a,x
11,779ab,y
809
16,814a,x
16,312a,x
12,562a,y
474
6,041c
6,252c
6,359c
683
917
672
755
Different letters within a row differed significantly (P < 0.05); n = 3.
Different letters within a column of same category differed significantly (P < 0.05).
1
Aldehydes included acetaldehyde, propanal, butanal, pentanal, 2-methyl butanal, 3-methyl butanal, pentanal,
and hexanal; alkanes included 2-methyl propane, butane, pentane, hexane, heptane, octane, 2,3-dimethylbutane,
2,3,3-trimethyl pentane, 2,3,4-trimethyl pentane, and 3-methyl-2-hepane; alkenes included 2-methyl-1-propene,
1-pentene, 2-pentene, 1-octene, and 2-octene; ketones included 2-propanone, 2-butanone, 2,3-dibutane dione,
and 1,2-cyclohexadione; and sulfur compounds included dimethyl sulfide, thiourea, and dimethyl disulfide.
a-d
x-z
significant effect on aldehydes or alkanes, the main volatiles associated with oxidation, but had significant effect
on ketones, alkenes, and sulfur compounds of cooked thigh
meats. The production of all groups of volatiles, except for
ketones, increased during holding, with the increase in
aldehydes being the greatest. The lack of differences in
sorghum treatments on the production of aldehydes in
cooked thigh meats was in agreement with the TBARS
TABLE 5. Major volatiles of cooked breast and leg meats at 0 and 12 h of holding
0 h holding
Volatile
Control
Ruby Red
Valpo Red
12 h holding
SEM
Control
Rudy Red
Valpo Red
SEM
(total ion counts × 104)
Breast meats
Acetaldehyde
Pentane
Propanal
2-Propanone
Heptane
Pentanal
Dimethyl disulfide
Octane
Hexanal
Thigh meats
Acetaldehyde
Pentane
Propanal
2-Propanone
Heptane
Pentanal
Dimethyl disulfide
Octane
Hexanal
40,192a
12,199
15,728a
60,404
1,562
1,174a
0
1,758
0
39,056a
9,661
10,465ab
73,861
1,236
0b
0
1,507
0
24,225b
6,989
7,422b
62,819
918
0b
0
1,750
0
3,510
1,462
2,005
4,664
184
38
0
276
0
75,123a
43,584a
97,412
69,535
6,119a
54,670a
10,860a
6,850
121,391
73,777a
38,764ab
101,032
76,825
5,144ab
52,299a
11,159a
7,146
113,016
52,870b
33,947b
87,903
67,751
4,317b
42,847b
6,339b
6,504
92,471
2,317
2,301
3,761
3,688
4,544
2,328
651
559
7,721
34,518a
37,250
24,039
79,472
7,081
8,703
2,912a
14,189
0
35,028a
32,934
26,532
79,064
6,273
6,329
2,892a
17,531
0
12,166b
39,673
22,756
79,139
6,963
3,638
754b
13,428
0
4,103
5,192
3,383
18,080
863
2,440
379
1,587
0
60,656
87,753
147,909
66,998
11,802
105,294
10,726a
20,282
266,020
76,673
66,786
190,390
100,165
9,377
106,104
6,541b
20,181
239,890
56,706
85,540
189,467
93,456
11,394
83,283
1,495c
19,847
283,795
18,671
6,110
43,713
14,152
1,051
22,918
783
2,627
45,854
Means within a row of the same holding time with no common superscript differ significantly (P < 0.05); n = 3.
a-c
1390
DU ET AL.
TABLE 6. Volatile profiles after different durations of holding (0 to 12 h) of cooked broiler thigh meat
from birds fed control diet or sorghum
Volatile1
0h
4h
8h
12 h
SEM
(total ion counts × 10
4
Aldehydes
Control
Ruby Red
Valpo Red
SEM
Alkanes
Control
Ruby Red
Valpo Red
SEM
Alkenes
Control
Ruby Red
Valpo Red
SEM
Ketones
Control
Ruby Red
Valpo Red
SEM
Sulfur compounds
Control
Ruby Red
Valpo Red
SEM
74,083c
74,436b
41,479c
9,401
265,368bc,y
447,899a,x
256,463bc,y
26,052
420,844ab
561,853a
391,774b
77,844
596,359a
629,755a
625,398a
133,893
81,707
78,476
75,704
71,647b
75,427b
72,535
8,110
93,628b
141,203a
91,923
15,563
109,113ab
116,738ab
109,105
20,698
143,951a
119,192ab
141,607
12,021
12,547
14,263
17,314
10,391ab
14,161ab
12,295ab
1,838
13,394a
14,916ab
14,988a
2,017
1,203
2,285
1,230
6,270b
7,551b
6,189c
620
84,772
87,508
83,905
18,339
14,732
10,028b
7,119
2,065
8,088b,y
17,777a,x
9,537bc,y
1,752
77,108
120,387
66,154
16,118
14,234x
15,610a,x
7,311y
1,962
38,231y
113,116x
77,789xy
17,546
15,827
16,427a
7,727
2,263
75,831
111,231
102,212
15,942
14,388
21,248
14,493
20,317x
15,835a,y
9,190z
1,215
3,024
730
1,165
Different letters within a row differed significantly (P < 0.05); n = 3.
Different letters within a column of same category differed significantly (P < 0.05).
1
Aldehydes included acetaldehyde, propanal, butanal, pentanal, 2-methyl butanal, 3-methyl butanal, pentanal
and hexanal; alkanes included 2-methyl propane, butane, pentane, hexane, heptane, octane, 2,3-dimethylbutane,
2,3,3-trimethyl pentane, 2,3,4-trimethyl pentane, and 3-methyl-2-hepane; alkenes included 2-methyl-1-propene,
1-pentene, 2-pentene, 1-octene, and 2-octene; ketones included 2-propanone, 2-butanone, 2,3-dibutane dione,
and 1,2-cyclohexadione; and sulfur compounds included dimethyl sulfide, thiourea, dimethyl disulfide, dimethyl
trisulfide.
a-d
x-z
values (Table 3). As in the volatiles of cooked breast meats,
hexanal and pentanal were the major aldehydes, and they
increased dramatically during sample holding. Pentane
was the main alkane, dimethyl disulfide was the main
sulfur compound, and 2-propanone was the main ketone
in cooked thigh meat, as in breast meat (Table 5). Dietary
Valpo Red sorghum significantly reduced the production
of dimethyl disulfide but had no effect on the amounts of
pentane and 2-propanone in cooked thigh meats.
Overall, feeding sorghum generally improved the oxidative stability of cooked breast meats, with the Valpo Red
cultivar being more effective than Ruby Red. Dietary Valpo
red cultuvar sorghum improved the early oxidative stability of raw thigh meat but was not effective for cooked
thigh meat.
ACKNOWLEDGMENTS
The assistance M. Goeger, T. Holsonbake, D. Weise and
the staff of Poultry Farm, Oregon State University, for
their assistance in feeding and taking care for the birds is
acknowledged. The generous donation of chicks (Foster
Farms, Northwest Division, Vancouver, WA), sorghum
(Natural Ovens of Manitowoc, Manitowoc, WI) is appreciated.
REFERENCES
Abdalla, A. E. M. 1999. Garlic supplementation and lipid oxidation in chicken breast and thigh meat after cooking and storage. Adv. Food Sci. 21:100–109.
Ahn, D. U., C. Jo, and D. G. Olson. 1999a. Headspace oxygen in
sample vials affects volatiles production of meat during the
automated purge-and-trap/GC analyses. J. Agric. Food Chem.
47:2776–2781.
Ahn, D. U., C. Jo, and D. G. Olson. 1999b. Volatile profiles of
raw and cooked turkey thigh as affected by purge temperature
and holding time before purge. J. Food Sci. 64:230–233.
Ahn, D. U., and S. M. Kim. 1998. Prooxidant effects of ferrous
iron, hemoglobin, and ferritin in oil emulsion and cookedmeat homogenates are different from those in raw-meat homogenates. Poult. Sci. 77:348–355.
Ahn, D. U., D. G. Olson, J. I., Lee, C. Jo, X. Chen, and C. Wu.
1998. Packaging and irradiation effects on lipid oxidation and
volatiles in pork patties. J. Food Sci. 63:15–19.
Ahn, D. U., F. H. Wolfe, J. S. Sim, and D. H. Kim. 1992. Packaging
cooked turkey meat patties while hot reduces lipid oxidation.
J. Food Sci. 57:1075–1077, 1115.
American Meat Science Association. 1991. Guidelines for meat
color evaluation. In Proc. 44th Recip. Meat Conf., Chicago, IL.
National Livestock and Meat Board, Chicago.
Cave, N. A., and V. D. Burrows. 1993. Evaluation of naked oat
(Avena nuda) in the broiler chicken diet. Can. J. Anim. Sci.
73:393–399.
El-Khalifa, A. O., and A. H. El-Tinay. 1994. Effect of fermentation
on protein fractions and tannin content of low- and hightannin cultivars of sorghum. Food Chem. 49:265–269.
DIETARY SORGHUM ON THE STABILITY OF BROILER MEAT
Greene, B. E. 1969. Lipid oxidation and pigment changes in raw
beef. J. Food Sci. 34:110–113.
Igene, J. O., K. Yamauchi, A. M. Pearson, J. I. Gray, and S. D. Aust.
1985. Evaluation of 2-thiobarbituric acid reactive substance
(TBARS) in relation to warmed-over flavour development in
cooked meat. J. Agric. Food Chem. 33:364–367.
Jimenez, R. L. M., J. C. Rogler, T. L. Housley, L. G. Butler, and
R. G. Elkin. 1994. Absorption and distribution of 14C-labeled
condensed tannins and related sorghum phenolics in chickens.
J. Agric. Food Chem. 42:963–967.
Maraschiello, C., C. Sarraga, and R. J. A. Garcia. 1999. Glutathione
peroxidase activity, TBARS, and alpha-tocopherol in meat
from chickens fed different diets. J. Agric. Food Chem.
47:867–872.
Sanchez, M. C., E. A. Jimenez, and C. F. Saura. 2000. Study of
low-density lipoprotein oxidizability indexes to measure the
antioxidant activity of dietary polyphenols. Nutr. Res.
20:941–953.
Santos, B. C., and A. Scalbert. 2000. Proanthocyanidins and tannin-like compounds—Nature, occurrence, dietary intake and
effects on nutrition and health. J. Sci. Food Agric. 80:1094–1117.
1391
SAS Institute. 1989. SAS User’s Guide. Version 6. 4th ed. SAS
Institute Inc., Cary, NC.
Schaefer, D. M., Q. Liu, C. Faustman, and M. C. Yin. 1995. Supranutritional administration of vitamins E and C improves antioxidant status of beef. J. Nutr. 125:1792S–1798S.
Shu, M. L., J. L. Gray, A. M. Booren, R. L. Cracket, and J. L. Gill.
1995. Assessment of off-flavor development in restructured
chicken nuggets using hexanal and TBARS measurements and
sensory evaluation. J. Sci. Food Agric. 67:447–452.
Yin, M. C., and C. Faustman. 1993. The influence of temperature,
pH, and phospholipid composition upon the stability of myoglobin and phospholipid: a liposome model. J. Agric. Food
Chem. 41:853–857.
Yokozawa, T., E. J. Cho, Y. Hara, and K. Kitani. 2000. Antioxidative activity of green tea treated with radical initiator 2,2′azobis(2-amidinopropane) dihydrochloride. J. Agric. Food
Chem. 48:5068–5073.
Yokozawa, T., E. Dong, T. Nakagawa, H. Kashiwagi, H. Nakagawa, S. Takeuchi, and H. Y. Chung. 1998. In vitro and in
vivo studies on the radical-scavenging activity of tea. J. Agric.
Food Chem. 46:2143–2150.