Meat Science 65 (2003) 513–521
www.elsevier.com/locate/meatsci
Effect of dietary vitamin E and irradiation on lipid oxidation, color,
and volatiles of fresh and previously frozen turkey breast patties§
K.C. Nam, B.R. Min, H. Yan, E.J. Lee, A. Mendonca, I. Wesley, D.U. Ahn*
Department of Animal Science, Iowa State University, Ames, IA 50011-3150, USA
Received 3 June 2002; received in revised form 3 September 2002; accepted 3 September 2002
Abstract
Turkey breast meat patties, prepared from the turkeys fed diets containing 0, 50, 100, or 200 IU of dl-a-tocopheryl acetate (TA)
per kg diet from 84 to 112 days of age, were aerobically packaged and irradiated at 0, 1.5, or 2.5 kGy. When dietary TA was
increased from 0 to 200 IU/kg diet, plasma and muscle vitamin E levels increased by 5- and 4-fold, respectively. Dietary TA at 100
IU/kg diet significantly improved the storage stability of turkey breast, and it was more distinct in irradiated than nonirradiated
meats. Both irradiation and dietary TA increased a*-values of turkey breast meat, but irradiation had a stronger impact. The redness of meat decreased during the 7-day storage, but irradiated meat maintained redder color than nonirradiated. Irradiated meat
produced more sulfur volatiles and aldehydes than nonirradiated meats, and dietary TA effectively reduced these compounds during storage. The effects of dietary TA on the reduction of off-odor volatiles were more distinct in previously frozen-stored meats
than in fresh meats.
# 2003 Elsevier Science Ltd. All rights reserved.
Keywords: Dietary vitamin E; Color; Lipid oxidation; Volatiles; Irradiation; Turkey breast meat
1. Introduction
Irradiation is permitted in poultry meat up to 3 kGy
to control pathogenic microorganisms such as Salmonella, Escherichia coli, and Listeira (Ahn et al., 1997).
One of the major concerns in irradiating meat, however,
is its negative impact on meat quality (Ahn, Jo, Du,
Olson, & Nam, 2000b; Ahn, Jo, & Olson, 2000a; Nam
& Ahn, 2002a, 2002b). Lipid oxidation is a special
problem in irradiated meat when it is stored aerobically
because oxygen is the most critical for lipid oxidation.
Irradiation has been reported to increase 2-thiobarbituric acid-reactive substances (TBARS) in aerobically
packaged raw poultry meat (Ahn et al., 1997; Du, Ahn,
Nam, & Sell, 2000; Hampson, Fox, Lakritz, & Thayer,
1996). Irradiated meats produce several off-odor volatile
§
Journal Paper No. J-19877 of the Iowa Agriculture and Home
Economics Experiment Station, Ames, IA 50011. Project No. 3706,
supported by the National Alliance of Food Safety and the Iowa
Turkey Federation.
* Corresponding author. Tel.: +1-515-294-6595; fax: +1-515-2949143.
E-mail address: duahn@iastate.edu (D.U. Ahn).
compounds that develop a characteristic aroma and the
amounts of off-odor volatiles produced are irradiation
dose-dependent (Ahn, Nam, Du, & Jo, 2001; Patterson
& Stevenson, 1995). Ahn et al. (2000b) suggested that
volatile compounds responsible for the irradiation offodor were produced by radiolytic degradation of amino
acid side chains, and the compounds produced by irradiation were distinctively different from those of lipid
oxidation. Ahn et al. (2000a) reported that panelists
distinguished the irradiated meat odor from the nonirradiated, describing the irradiated meat odor as a
‘‘barbecued corn-like.’’
Free radicals produced by ionizing radiation are the
main source that induces oxidation of lipids and radiolysis of amino acids, which result in characteristic
irradiation off-odor. Raw meat contains intrinsic antioxidant factors, but their amounts are too small to
protect meat from the free radical-induced chemical
changes. Therefore, the presence of an extraneous antioxidant that can scavenge free radicals will be effective
in reducing quality changes in meat by irradiation.
Vitamin E functions as a lipid-soluble antioxidant and is
capable of quenching free radicals in meat during storage (Gray, Gomma, & Buckley, 1996). The beneficial
0309-1740/03/$ - see front matter # 2003 Elsevier Science Ltd. All rights reserved.
PII: S0309-1740(02)00243-7
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K.C. Nam et al. / Meat Science 65 (2003) 513–521
effect of dietary vitamin E on meat quality has been
reported by many researchers (Ahn, Kawamoto, Wolfe,
& Sim, 1995; Morrissey, Brandon, Buckley, Sheehy, &
Frigg, 1997; Sarraga & Garcia-Regueiro, 1999). The
benefit of dietary vitamin E is related to the increased
vitamin E concentration in muscle tissues, which
improves color stability and diminishes lipid oxidation
and off-flavor development. The muscle vitamin E may
not only retard lipid oxidation but also reduce production of sulfur volatiles responsible for the characteristic
irradiation off-odor. The objective of this study was to
determine the effectiveness of dietary vitamin E on lipid
oxidation, color, and volatiles development in irradiated
turkey breast meat during refrigerated storage.
2. Materials and methods
2.1. Dietary treatments and sample preparation
A total of 120 12-week-old male Large White turkeys
raised on a corn–soybean meal-based diet were divided
into 16 pens (eight birds/pen) and four pens of turkeys
were randomly assigned to diets containing 0, 50, 100,
or 200 IU of dl-a-tocopheryl acetate (TA)/kg diet. Then
each of the diet was fed to turkeys from 12 to 16 weeks
of age. Weight gains of the turkeys during the treatment
period were calculated. Blood samples were collected
from two birds/pen 1 day before slaughter. Plasma was
separated by centrifuging the blood sample at 2000g
for 15 min and was used to determine vitamin E content. At the end of the feeding trial, three birds per pen
were randomly selected and slaughtered following
USDA guidelines (USDA, 1982). Carcasses were chilled
in ice water for 3 h, then drained in a cold room. Breast
muscles were deboned from the carcasses 24 h after
slaughter. Skins and visible fat were removed from the
breasts. Breast muscles from two birds from the same
pen were pooled, ground twice a 3-mm plate, and used
as a replication (thus, four replications). Breast patties
(approximately 100 g) were prepared from each of the
pooled ground breasts. The breasts were individually
packaged in oxygen-permeable bags (polyethylene, 46,
2 MIL, Associated Bag Company, Milwaukee, WI) and
irradiated with accelerated electrons using a Linear
Accelerator (Circe IIIR, Thomson CSF Linac, SaintAubin, France) to an average dose of 0, 1.5, or 2.5 kGy.
The energy level of the Lenear Accelerator was 10 MeV,
power level was 10 kW, and average dose rate was 88.1
kGy/min. Alanine dosimeters placed on the top and
bottom surfaces of a sample were read using a 104
Electron Paramagnetic Resonance Instrument (Bruker
Instruments Inc., Billerica, MA) to determine the
absorbed doses. Irradiated samples were kept at 4 C,
and color, lipid oxidation, and volatiles of the samples
were determined after 0 and 7 days of storage.
To determine the effects of freezing on the volatile
profiles, the whole breast muscles (one bird/pen) were
frozen at 40 C for 3 months and thawed for 3 days at
4 C before use. The thawed breast meats were used to
prepare patties. The patties were irradiated, packaged,
and stored as described above. The volatiles of the patties from previously frozen meat also were determined
after 7 days of aerobic storage at 4 C.
2.2. Vitamin E content and fatty acid composition
Plasma and breast muscles were analyzed for a-tocopherol content according to the method of Du and Ahn
(2002). Vitamin E was quantified using 5a-cholestane as
an internal standard. The results were expressed as mg
vitamin E/kg plasma or muscle. Fat contents and fatty
acid compositions of turkey breast meat were analyzed
using a GC (HP 6890, Hewlett Packard Co.). Fatty acids
were identified by comparison of retention times to known
standards. Relative quantities were expressed as weight
percentage of total fatty acids (Du, Ahn, & Sell, 2001).
2.3. Measurement of color values
CIE color values were measured on the surface of
samples using a LabScan color meter (Hunter Associated Labs. Inc., Reston, VA) that had been calibrated
against a black and a white reference tiles covered with
the same packaging materials as used for samples. The
CIE L- (lightness), a- (redness), and b- (yellowness)
values were obtained using an illuminant A. Area view
and port size were 0.25 and 0.40 inch, respectively. An
average value from both upper and bottom location on
a sample surface was used for statistical analysis.
2.4. Analysis of 2-thiobarbituric acid-reactive substances
(TBARS)
Lipid oxidation was determined by measuring TBARS
content. Minced sample (5 g) was placed in a 50-ml test
tube and homogenized with 15 mL of deionized distilled
water (DDW) using a Brinkman Polytron (Type PT 10/
35, Brinkman Instrument Inc., Westbury, NY) for 15 s
at high speed. The meat homogenate (1 ml) was transferred to a disposable test tube (13100 mm), and
butylated hydroxytoluene (7.2%, 50 ml) and thiobarbituric acid/trichloroacetic acid [20 mM TBA and 15%
(w/v) TCA] solution (2 ml were added. The sample was
mixed using a vortex, then incubated in a 90 C water
bath for 15 min to develop color. After cooling for 10
min in cold water, the samples were vortexed and centrifuged at 3000g for 15 min at 5 C. The absorbance
of the resulting upper layer was read at 531 nm against a
blank prepared with 1 ml DDW and 2 ml TBA/TCA
solution. The amounts of TBARS were expressed as mg
of malonedialdehyde (MDA) per kg of meat.
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K.C. Nam et al. / Meat Science 65 (2003) 513–521
2.5. Analysis of volatile compounds
To determine the volatiles responsible for off-odor of
the samples, a dynamic headspace analysis was performed using a Solatek 72 Multimatrix vial autosampler
and a Purge & Trap Concentrator 3000 (TekmarDohrmann, Cincinnati, OH) connected to a gas
chromatography-mass spectrometry (GC/MS, HewlettPackard Co., Wilmington, DE) according to the method
of Ahn et al. (2001). Minced sample (3 g) was placed in
a 40-ml sample vial, and the vials were then flushed with
helium gas (40 psi) for 3 s and capped airtight with a
Teflon*fluorocarbon resin/silicone septum (I-Chem Co.,
New Castle, DE). The maximum waiting time of a
sample in a refrigerated (4 C) loading tray was 2.5 h or
less to minimize oxidative changes during the waiting
period before starting analysis. The meat sample was
purged with helium gas (40 ml/min) for 13 min at 40 C.
Volatiles were trapped using a Tenax/charcoal/silica
column (Tekmar-Dohrmann) and desorbed for 2 min at
225 C, focused in a cryofocusing module ( 90 C), and
then thermally desorbed into a column for 60 s at
225 C.
An HP-624 column (7.5 m, 0.25 mm i.d., 1.4 mm
nominal), an HP-1 column (52.5 m, 0.25 mm i.d.,
0.25?mm nominal; Hewlett-Packard Co., Wilmington,
DE), and an HP-Wax column (7.5 m, 0.250 mm i.d.,
0.25 mm nominal) were connected using zero deadvolume column connectors (J&W Scientific, Folsom,
CA). Ramped oven temperature was used to improve
volatile separation. The initial oven temperature of 0 C
was held for 2.50 min. After that, the oven temperature
was increased to 15 C at 2.5 C per min, increased to
45 C at 5 C per min, increased to 110 C at 20 C per
min, and then increased to 220 C at 10 C per min and
held for 2.25 min at that temperature. Constant column
pressure at 20.5 psi was maintained. The ionization
potential of mass selective detector (Model 5973; HewlettPackard Co.) was 70 eV, and the scan range was 29–450
m/z. Identification of volatiles was achieved by comparing mass spectral data of samples with those of the
Wiley library (Hewlett-Packard Co.). Standards, when
available, were used to confirm the identification by the
mass selective detector. The area of each peak was integrated using ChemStationTM software (Hewlett-Packard
Co.), and the total peak area (total ion counts104) was
reported as an indicator of volatiles generated from the
meat samples.
(SAS Institute, 1995). Student–Newman–Keul’s multiple range tests were used to compare the significant differences of the mean values of treatments (P < 0.05).
Mean values and standard error of the means (SEM)
were reported.
3. Results and discussion
3.1. Accumulation of vitamin E and fat content
The supplementation of tocopheryl acetate (TA) to
turkeys increased the vitamin E levels of plasma and
muscle tissues, but had no effect on the weight gains of
turkeys (Table 1). The levels of a-tocopherol in plasma
and breast muscle of turkeys increased up to 5.5-fold
and 4-fold of the control, respectively, with 200 IU/kg
of dietary treatment. The levels of a-tocopherol in
plasma and muscle were increasing with the increase of
dietary TA, but were not exactly linear with the supplemented TA. The total lipid content of turkey breast
meat supplemented with TA was higher than that of the
control, but minor differences in fatty acid compositions
were observed (Table 2).
3.2. Lipid oxidation
The TBARS values of breast meat from turkeys fed
diets supplemented with TA were lower than that of the
control at Day 0 and Day 7, but the antioxidant effects
of dietary TA were highly significant when the meats
were irradiated and stored (Table 3). Lipid oxidation
was not a problem in turkey breast patties at day 0
regardless of dietary TA and irradiation dose.
After 7 days of aerobic storage, irradiation accelerated lipid oxidation significantly in meat from turkeys
fed 0 IU and 50 IU dietary TA. The TBARS values of
meats from turkeys fed 100 IU and 200 IU dietary TA
also were increased, but the increases were small. Supplementing turkeys 100 IU TA/kg diet or more was
effective in minimizing oxidative changes in turkey
Table 1
Effect of dietary vitamin E on weight gain and a-tocopherol content of
turkey plasma and breast tissuea
Dietary vitamin E
Weight gainb (kg)
2.6. Statistical analysis
The experimental design was to determine the effects
of dietary vitamin E on the color, lipid oxidation, and
volatile compounds of irradiated samples during 7-day
storage. Analysis of variance was conducted by the
procedure of General Linear Model using SAS software
0 IU
50 IU
100 IU
200 IU
SEM
5.13
5.09
5.17
5.18
0.08
1.85c
1.64c
3.02b
2.24b
4.69a
3.47a
0.15
0.07
-Tocopherol content (g/g)
Plasma
0.84d
Breast tissue
0.85d
a
Mean values with different letters within a row are significantly
different (P<0.05), n=8.
b
Weight gain during the supplementation of vitamin E from 12 to
16 weeks, n=20.
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K.C. Nam et al. / Meat Science 65 (2003) 513–521
Table 2
Lipid content and fatty acid composition of turkey breast meat affected by different levels of dietary vitamin Ea
Dietary vitamin E
0 IU
50 IU
100 IU
200 IU
SEM
Lipid content (%)
1.29b
1.58a
1.53a
1.53a
0.06
(% of total lipid)
Myristic acid
Palmitoleic acid
Palmitic acid
Oleic acid
Stearic acid
Linoleic acid
Linolenic acid
Arachidonic acid
Unknown
0.96
2.18b
20.89b
34.26
2.99
26.62b
2.13ab
6.11
3.86
0.95
2.21b
20.54b
34.38
2.65
27.85a
2.27a
6.04
3.11
0.97
2.36a
21.77a
34.03
2.72
26.46b
1.90b
6.07
3.72
0.97
2.41a
21.27a
34.01
3.04
26.06b
2.08ab
6.27
3.89
0.03
0.06
0.12
0.24
0.32
0.23
0.06
0.12
0.05
a
Mean values with different letters within a row are significantly
different (P<0.05), n=8.
Table 3
TBARS values of aerobically packaged turkey breast patties affected
by dietary vitamin E and irradiation during storage at 4 Ca (mg
MDA/kg meat)
Irradiation
Dietary vitamin E
0 IU
50 IU
100 IU
200 IU
SEM
Day 0
0 kGy
1.5 kGy
2.5 kGy
SEM
0.15ay
0.19y
0.28ax
0.02
0.13aby
0.18x
0.19bx
0.01
0.10by
0.15xy
0.18bx
0.01
0.12ab
0.17
0.14b
0.01
0.01
0.01
0.02
Day 7
0 kGy
1.5 kGy
2.5 kGy
SEM
0.46az
1.12ay
1.24ax
0.04
0.32by
0.64bx
0.63bx
0.04
0.22by
0.29cy
0.37bx
0.02
0.22by
0.28cx
0.32bx
0.02
0.03
0.04
0.16
a
Different letters (a–c) within a row are significantly different
(P<0.05), n=4. Different letters (x–z) within a column with same
storage day are significantly different (P <0.05).
breast meat patties during the 7 day storage under
aerobic conditions, and the antioxidant effect of dietary
TA was more distinct in irradiated meat because irradiated meats were more susceptible to lipid oxidation
than nonirradiated meats during storage. Galvin, Morrissey, and Buckley (1998) reported that supplementing
chickens with 200 mg of a-tocopheryl acetate/kg feed
prevented the accelerated increase of TBARS by irradiation during storage. Jensen, Skibsted, Jakobsen, and
Bertelsen (1995) reported that feeding broilers with a
diet supplemented with 198 mg TA/kg diet was sufficient to ensure stability of raw meat during chill and
freezer storage, but Morrissey, Sheehy, Galvin, and
Buckley (1998) reported that turkey diet should contain
at least 300 mg TA/kg in order to ensure a high degree
of oxidative stability in turkey meat.
3.3. Color changes
Dietary TA and irradiation significantly influenced
the color of aerobically packaged turkey breast meat
(Table 4). Irradiation increased the color a*-values of
turkey breast meat irrespective of dietary TA, and the
degree of color increase was irradiation dose-dependent.
Nam and Ahn (2002a, 2002b) reported that irradiation
produced carbon monoxide (CO), and the increase of
a*-values in irradiated meat were caused by CO-myoglobin. If heme pigments are the major compounds that
disulfide lipid oxidation in meat, combination of CO to
heme pigment will reduce their catalytic activities.
However, free ionic iron was the major compound
involved in lipid oxidation of raw meat. Heme pigments
were the major catalyst of lipid oxidation in cooked
meat, washed muscle, and oil emulsions (Ahn & Kim
1998a, 1998b). Dietary TA also increased the redness of
meat but was less critical than irradiation. The color of
irradiated breast meat from turkeys fed 200 IU TA/kg
diet was visually much redder than the control, but
color L*- and b*-values were not much changed by
irradiation and dietary TA.
Regardless of irradiation and dietary TA treatments,
the color a*-values of turkey breast patties decreased
significantly (P > 0.01) after 7 days of storage under
aerobic conditions. This indicated that heme pigments
were oxidized during the storage period under aerobic
conditions. The color of irradiated breast patties, however, was still redder than that of the nonirradiated
patties. Breast meats from turkeys fed 100 IU TA/kg
diet or more had higher a*-values than control for both
nonirradiated and 2.5 kGy-irradiated samples. Therefore, dietary TA would be effective in stabilizing the
color of turkey breast meat during aerobic storage.
Lynch, Faustman, Chan, Kerry, and Buckley (1998)
reported that a-tocopherol maintained oxymyoglobin
by enhancing cytochrome b5-mediated reduction of
metmyoglobin. The color stabilization effect of dietary
TA in beef and pork by inhibiting autoxidation of oxymyoglobin also had been reported by others (Faustman,
Chan, Lynch, & Joo, 1996; Gray et al., 1996).
3.4. Volatiles of fresh turkey breast
Table 5 shows the effect of dietary TA on volatile
production in turkey breast meat before irradiation.
Pentane, 2-propanone, and carbon disulfide were the
major volatiles in nonirradiated turkey meat at Day 0,
and dietary TA significantly increased the production of
2-propanone but decreased carbon disulfide. Pentane,
2-propanone and carbon disulfide also were the major
volatiles in turkey meat at Day 7, but two hydrocarbons
(hexane and octane) and two aldehydes (propanal and
butanal) were newly produced from the meat. After 7 days
of storage, carbon sulfide was not detected in breast meat
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K.C. Nam et al. / Meat Science 65 (2003) 513–521
Table 4
CIE color values of aerobically packaged turkey breast patties affected by dietary vitamin E and irradiation during storage at 4 Ca
Irradiation
Dietary vitamin E
Day 0
L* value
0 kGy
1.5 kGy
2.5 kGy
SEM
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
46.1
45.9
44.2
0.9
45.8
45.1
43.8
0.9
42.7
44.1
43.2
0.9
45.3
46.5
44.6
0.8
0.9
0.9
0.8
49.2
49.6
49.6
0.6
48.8
50.8
49.4
0.6
48.3
49.6
50.0
0.6
48.0
49.2
50.0
0.7
0.6
0.7
0.6
8.1az
9.3ay
10.9ax
0.3
7.9az
8.8aby
10.5ax
0.3
0.3
0.3
0.3
14.1
13.6a
14.0ab
0.2
14.4
13.7a
14.4a
0.3
0.3
0.2
0.3
a* value
0 kGy
1.5 kGy
2.5 kGy
SEM
7.0bz
8.1by
9.5cx
0.3
b* value
0 kGy
1.5 kGy
2.5 kGy
SEM
13.4x
12.8by
12.7cy
0.2
6.9bz
8.4by
9.9bcx
0.3
13.8
13.3ab
13.3bc
0.3
3.2bz
4.5y
5.3bx
0.2
11.1
11.6a
11.3
0.2
3.7ay
4.0y
4.9bx
0.2
10.8
10.8b
11.3
0.3
4.2ay
4.4y
6.3ax
0.3
11.4
11.6a
11.4
0.2
4.3az
5.0y
6.4ax
0.2
11.6
11.7a
11.9
0.2
0.2
0.2
0.3
0.2
0.2
0.2
a
Different letters (a–c) within a row with same storage day are significantly different (P>0.05), n=4. Different letters (x–z) within a column with
same color value are significantly different (P <0.05).
from turkeys fed diets containing 50 IU or more of TA/kg,
and the amount of carbon disulfide in breast meat also was
smaller with the TA-supplemented diets.
At Day 0, irradiation generated a few new volatiles
not found in nonirradiated meat such as 2-methyl-1Table 5
Volatile profiles of nonirradiated, aerobically packaged raw turkey
breast patties affected by dietary vitamin E during storage at 4 Ca
(total ion counts104)
Volatiles
Dietary vitamin E
0 IU
50 IU
100 IU
200 IU
SEM
Day 0
Pentane
2-Pentene
2-Propanone
Dimethyl sulfide
Carbon disulfide
Octane
Total
1238
99
6214c
328b
7406a
13
15300a
1004
93
7478b
322b
2566b
0
11465c
1225
108
11236a
507a
1100b
0
14177ab
1001
61
10506a
288b
1027b
0
12883bc
100
13
252
25
448
6
528
Day 7
Pentane
2-Pentene
Propanal
2-Propanone
Dimethyl sulfide
Carbon disulfide
Hexane
Butanal
Octane
Total
2314b
39
0b
11742
243a
1460a
99
111a
71a
16172a
4913a
88
84a
10617
0b
477b
180
118a
104a
16782a
1931b
0
142a
11880
0b
284b
127
90a
12b
14542a
851b
0
0b
10240
0b
280b
105
0b
0b
11476b
622
25
28
395
11
176
19
7
16
980
a
Different letters within a row with same storage day are significantly different (P <0.05), n=4.
propene, 1-butene, 1-pentene, 1-heptene, heptane, and
toluene (Tables 6 and 7). Ahn, Olson, Jo, Love, and Jin
(1999) and Jo and Ahn (2000) reported that the production of 1-heptene and 1-nonene were proportional to
irradiation dose and suggested that 1-heptene and
1-nonene could be used as indicators for irradiation. At
Day 0, the amounts of carbon disulfide, butanal, and
total volatiles in turkey meat irradiated at 1.5 and 2.5
kGy decreased as the amount of dietary TA increased
(Tables 6 and 7). While significantly smaller amounts of
sulfur-volatiles (dimethyl sulfide and carbon disulfide)
were detected from the irradiated turkey breasts after 7
days of storage under aerobic conditions, greater
amounts of propanal and butanal were detected. Ahn et
al. (2000b) reported that sulfur-volatiles, the main volatiles responsible for irradiation off-odor in meat, were
highly volatile and easily evaporated under aerobic
conditions. Among the dietary TA treatments, 200 IU
TA/kg diet was the most effective in reducing the
amounts of both sulfur-volatiles and aldehydes. Little
difference in the profiles of volatiles between turkey
breasts irradiated at 1.5 and 2.5 kGy were found, but
turkey breast meat irradiated at 2.5 kGy produced
dimethyl disulfide (Table 7).
3.5. Volatiles of previously frozen turkey
A greater number of hydrocarbons and aldehydes
were detected in previously frozen than in fresh turkey
meats, and the effect of dietary TA on volatile production became more distinct in previously frozen than in
fresh meat (Tables 6–8). At day 0, significantly lower
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K.C. Nam et al. / Meat Science 65 (2003) 513–521
amounts of aldehydes, hydrocarbons, and total volatiles
were detected in meat from turkeys fed diets supplemented with TA, and the decrease in those volatiles was
proportional to dietary TA. A 200 IU of TA/kg diet was
highly effective in stabilizing turkey breast meat from
oxidative changes in previously frozen-stored turkey
breast meat. 2-Propanone, a predominant volatile in
raw meat, was not detected in previously frozen meat. A
considerable amount of hexanal was detected in turkey
breast previously frozen stored, and hexanal was the
predominant volatile at Day 7. More than 100 IU of
dietary TA was effective in reducing hexanal content,
which is highly correlated to lipid oxidation, in previously frozen-stored turkey breast meat.
Table 6
Volatile profiles of 1.5 kGy-irradiated, aerobically packaged raw turkey breast patties affected by dietary vitamin E during storage at 4 Ca (total ion
counts104)
Volatiles
Dietary vitamin E
Day 0
2-Methyl-1-propene
1-Butene
1-Pentene
Pentane
2-Pentene
Propanal
2-Propanone
Dimethyl sulfide
Carbon disulfide
Hexane
Butanal
1-Heptene
Heptane
Toluene
Octane
Total
a
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
167
186
22
792ab
55
0
9352
1087
5425a
51
137a
29
29
344a
76
17753a
235
244
47
1136a
95
0
8530
1343
2584b
68
88b
80
63
222b
74
14809b
191
211
20
994ab
91
0
8132
1263
2269b
72
0c
75
49
225b
66
11389c
172
208
16
487b
19
0
7785
1212
875c
54
0c
52
30
349a
63
11319c
16
17
19
143
23
–
475
75
104
22
10
20
18
29
12
903
0b
0
0
1804b
0
975b
11083
178a
345a
92b
134b
19b
96a
141b
74a
14944b
70a
0
0
3517a
0
1493a
11918
193a
320a
157a
173a
96a
98a
197a
87a
18325a
37ab
0
0
2132b
0
873b
11815
117b
159ab
106ab
120b
36b
68b
141b
57a
15665b
0b
0
0
1015b
0
460c
11540
125b
41b
111ab
104b
0b
0c
122b
0b
13520b
11
–
–
417
–
89
316
17
53
15
8
15
4
12
11
696
Different letters within a row with same storage day are significantly different (P<0.05), n=4.
Table 7
Volatile profiles of 2.5 kGy-irradiated, aerobically packaged raw turkey breast patties affected by dietary vitamin E during storage at 4 Ca (total ion
counts104)
Volatiles
Dietary vitamin E
Day 0
2-Methyl-1-propene
1-Butene
1-Pentene
Pentane
2-Pentene
Propanal
2-Propanone
Dimethyl sulfide
Carbon disulfide
Hexane
Butanal
Benzene
1-Heptene
Dimethyl disulfide
Toluene
Octane
Total
a
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
164b
187ab
20
1566
144a
0b
9318b
1333b
13084a
71ab
95a
38
17
62
581
77a
26761a
124c
147b
20
903
77b
85a
9717ab
1295b
1411b
16b
0b
18
17
18
570
14b
14432b
141bc
163b
15
877
76b
0b
10078a
1491ab
831b
34ab
0b
18
15
0
565
14b
14318b
191a
218a
53
1115
101ab
0b
9945ab
1678a
1023b
97a
0b
0
56
0
501
68a
15041b
8
11
18
170
17
14
179
87
18
18
4
17
17
21
42
10
2532
36
0
0
1433
0
930b
11788
140
405a
268
163
0
82
16
171
25a
15461
14
82
0
2153
0
1676a
11106
147
192b
248
177
0
110
87
172
53a
16221
0
31
0
1387
0
707b
12527
136
90b
227
164
0
100
0
200
30a
15604
16
19
0
1092
0
768b
12168
145
42b
266
164
0
93
65
182
0b
15025
15
20
–
287
–
158
351
19
49
57
16
–
17
21
13
9
627
Different letters within a row with same storage day are significantly different (P<0.05), n=4.
519
K.C. Nam et al. / Meat Science 65 (2003) 513–521
Previously frozen turkey breast produced more sulfur
volatiles than fresh turkey breast meat by irradiation
(Tables 6, 7, and 9). The major sulfur volatiles produced
in turkey breast by irradiation were methanethiol and
dimethyl disulfide. Benzene and toluene also were
increased by irradiation. Ahn et al. (2000b) reported
that S-containing volatiles produced by the radiolytic
degradation of sulfur amino acids were responsible for
the off-odor in irradiated meat, and their amounts were
highly dependent upon irradiation dose. Dietary TA
lowered the production of dimethyl disulfide, and the
compound was not detected in the meat from turkeys
Table 8
Volatile profiles of nonirradiated, aerobically packaged turkey breast (frozen for 3 mo) patties affected by dietary vitamin E during the storage at
4 Ca (total ion counts104)
Volatiles
Dietary vitamin E
Day 0
Methanethiol
Pentane
Propanal
Dimethyl sulfide
Carbon disulfide
Hexane
Benzene
1-Heptene
Heptane
Pentanal
Toluene
4-Octene
Octane
2-Octene
3-Methyl-2-heptene
Hexanal
Total
a
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
0b
3353a
0
571
988a
237a
88a
17b
265a
13
24
378a
867a
239a
340a
1142a
8526a
0b
2223b
0b
646
331b
131b
0b
0b
118b
0
0
285a
608ab
161ab
268a
225b
5000b
0b
1463c
0
518
91b
47c
0b
0b
45c
0
0
92b
309b
96b
75b
115b
2855c
0
0d
0b
278
0b
0c
0b
311a
0c
27
0
0b
0c
0c
0b
0b
616d
58
162
–
88
171
18
1
20
17
15
7
60
99
30
55
138
315
0
5219a
56
0
1749
268
0
0
545a
148
0
0
554a
0
0
5102a
13641a
0
3100b
62
0
1858
248
0
0
363ab
122
0
0
529a
0
0
4891a
11173a
0
1636c
0
0
1015
227
0
0
372ab
176
0
0
466a
0
0
2658b
6550bc
0
452d
0
0
1441
266
0
0
211b
101
0
0
95b
0
0
1654b
4220c
–
375
56
–
475
57
–
–
32
52
–
–
19
–
–
754
627
Different letters within a row with same storage day are significantly different (P<0.05), n=4.
Table 9
Volatile profiles of 1.5 kGy-irradiated, aerobically packaged turkey breast (frozen for 3 month) patties affected by dietary vitamin E during storage
at 4 Ca (total ion counts104)
Volatiles
Dietary vitamin E
Day 0
Methanethiol
Pentane
Propanal
Dimethyl sulfide
Carbon disulfide
Hexane
Benzene
1-Heptene
Heptane
Pentanal
Dimethyl disulfide
Toluene
4-Octene
Octane
2-Octene
3-Methyl-2-heptene
Hexanal
Total
a
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
205
3949a
0
738
544
200b
260a
143a
192a
0
155a
233
178
634a
134a
164
501
8641a
291
1786b
0
204
240
257a
204b
84b
196a
0
66b
205
201
484a
124a
184
56
4645b
0
1302b
0
311
89
109c
190b
17c
57b
0
37b
186
74
215b
38b
67
55
2797c
83
600b
0
425
82
125c
192b
0c
22b
0
0b
149
53
212b
33b
91
30
2097c
152
392
–
63
55
12
13
13
24
–
32
50
35
61
18
30
64
736
0
10036a
132a
0
0
496a
92
191a
589a
194
0
118
0
629a
269a
0
5635a
18385a
0
7641b
116a
0
0
361b
69
148ab
408a
241
0
85
0
599a
127b
0
5486a
15286a
0
5246c
36b
0
0
305b
92
119bc
409a
221
0
136
0
428a
119b
0
3596b
10711b
0
2382d
0b
0
0
159c
52
80c
174b
77
0
110
0
180b
58c
0
1842c
5118c
–
640
14
–
–
40
12
17
57
58
–
18
–
67
10
–
986
1215
Different letters within a row with same storage day are significantly different (P<0.05), n=4.
520
K.C. Nam et al. / Meat Science 65 (2003) 513–521
Table 10
Volatile profiles of 2.5 kGy-irradiated, aerobically packaged turkey breast (frozen for 3 mo) patties affected by dietary vitamin E during storage at
4 Ca (total ion counts104)
Volatiles
Dietary vitamin E
Day 0
Methanethiol
Pentane
Propanal
Dimethyl sulfide
Carbon disulfide
1-Hexene
Hexane
Benzene
3-Methyl butanal
1-Heptene
Heptane
Pentanal
Dimethyl disulfide
Toluene
4-Octene
Octane
2-Octene
3-Methyl-2-heptene
Hexanal
Total
a
Day 7
0 IU
50 IU
100 IU
200 IU
SEM
0 IU
50 IU
100 IU
200 IU
SEM
490a
4651a
0
895a
672a
48
310a
258
59
211a
239ab
52a
653a
427
124
466b
94ab
50b
861a
10566a
380ab
2432b
0
281b
240b
63
354a
236
0
174a
270a
0b
29b
355
251
784a
148a
213a
52b
6268b
357ab
1251bc
0
471b
0b
50
264a
384
0
127ab
110ab
0b
18b
399
170
479b
127ab
178ab
28b
4419bc
73b
585c
0
323b
92b
0
157b
294
0
62b
81b
0b
0b
242
119
302b
71b
63b
17b
2486c
85
422
–
97
76
27
33
38
17
29
42
9
117
55
44
83
17
35
84
695
0
9955a
350
0
0
0
362a
142
0
196
484a
233
0
213
0
455a
251a
0
7117ab
19761a
0
6043b
290
0
0
0
275b
132
0
175
379a
199
0
207
0
329b
116b
0
8180a
16328b
0
4692b
240
0
0
0
213b
116
0
113
232b
281
0
129
0
204c
98b
0
5050ab
11371c
0
2438c
154
0
0
0
213b
133
0
120
156b
108
0
207
0
168c
46c
0
2851b
6597d
–
501
120
–
–
–
24
12
–
25
41
46
–
41
–
37
12
–
1217
1083
Different letters within a row with same storage day are significantly different (P<0.05), n=4.
fed 200 IU of TA. Vitamin E from the dietary TA
accumulated in cell membrane protected cells from
damage caused by free radicals produced by irradiation.
Huber, Brasch, and Waly (1953) reported that use of
antioxidants such as ascorbate, citrate, tocopherol, gallate esters, and polyphenols was effective in reducing the
odor of irradiated meat. As in fresh meat, a 200 IU of
TA/kg diet was effective in reducing the representative
irradiation off-odor volatiles in previously frozen turkey
breast meat. At day 7, almost all sulfur volatiles disappeared, but significant amounts of hydrocarbons and
aldehydes were produced. Especially, the amounts of
pentane and hexanal increased drastically, and they
were the two predominant volatiles in the previously
frozen turkey breast meat at 7 days. Dietary TA, however, was still effective in reducing the predominant
volatiles, and the decrease of the volatiles was TA-dose
dependent.
The production of sulfur-volatiles, hydrocarbons, and
aldehydes in turkey breast meat was irradiation dosedependent (Table 10): dimethyl disulfide was produced
the most with 2.5 kGy irradiation at 0 day, and hexanal
and pentane were produced the most in 2.5 kGy meat
after 7 days of aerobic storage. More distinct effect of
dietary TA was found in 2.5 kGy-irradiated turkey meat
than in nonirradiated meat. Supplementing a 200 IU of
TA/kg diet reduced the amounts of hexanal by 60% of
the control. Therefore, dietary TA was effective in
reducing both irradiation-dependent and lipid oxidation-dependent off-odor volatiles from previously frozen
turkey meat.
4. Conclusion
Dietary vitamin E protected turkey breast meat from
oxidative changes, and its effect was prominent when
the meat was structurally damaged by a freezing and
thawing cycle, then irradiated and stored under aerobic
conditions. The effects of dietary vitamin E were highly
dependent upon the TA levels, and at least 100 IU/kg of
dietary TA was needed to significantly reduce lipid oxidation and off-odor volatiles in irradiated turkey breast
patties.
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