Dietary Vitamin E Affects Lipid Oxidation and Total Volatiles
of Irradiated Raw Turkey Meat
D.U. AHN, J.L. SELL, M. JEFFERY, C. JO, X. CHEN, C. WU, and J.I. LEE
ABSTRACT
Breast and leg meat patties, prepared from turkeys fed diets containing
25, 200, 400 or 600 IU of dl-a-tocopheryl acetate (TA) per kg diet, were
irradiated at 0 or 2.5 kGy with vacuum or loose packaging. The effects
of dietary TA on storage stability and production of volatiles in irradiated
raw turkey meat were determined. Dietary TA at . 200 IU/kg decreased
lipid oxidation and reduced total volatiles of raw turkey patties after 7days of storage. However, the antioxidant effects of dietary TA were
more notable when the patties were loosely packaged than when vacuum-packaged. Irradiation increased lipid oxidation of raw turkey meats
only when loosely packaged but had limited effects on formation of total
volatiles after storage at 47C for 7 days or longer.
Key Words: vitamin E, lipid oxidation, volatiles, irradiation, turkey meat
INTRODUCTION
TREATMENTS SUCH AS IRRADIATION, carcass wash with organic
acids, sanitizers, hot water, chlorine, phosphates, and ozone,
have been tested to prevent, reduce or eliminate pathogenic bacteria on raw meat. Irradiation has been reported to guarantee
safety by eliminating pathogenic bacteria in raw meat (Gants,
1996). It is permitted in poultry meat up to 3 kGy to control
pathogenic microorganisms such as Salmonella, Escherichia
coli, and Listeria. A major concern in irradiating meat, however,
is its effect on meat quality, mainly related to the free radicals
reaction and off-odor. Irradiation, at 1.5- to 10-kGy doses, has
been reported to increase thiobarbituric acid values (TBARS) in
turkey breast meat and fish muscles (Al-Kahtani et al., 1996;
Hampson et al., 1996). Katusin-Razem et al. (1992) and Thayer
et al. (1993) reported that irradiation-induced oxidative chemical
changes were dose dependent and that the presence of oxygen
had a notable effect on rate of oxidation.
Lynch et al. (1991) showed that irradiated turkey breast fillet
produced unpleasant odor notes when stored in oxygen impermeable film and the odors were different from those from unirradiated samples. Heath et al. (1990) and Hashim et al. (1995)
also reported that irradiating uncooked chicken meat produced
a characteristic bloody and sweet aroma that remained after the
meat was cooked. Others, however, indicated that irradiation had
no detrimental effect on flavor of vacuum-packaged raw meat
or cured meat and electron beam treatment had little effect on
odor or flavor of reheated meat with sous-vide treatment (Shahidi et al., 1991; Shamsuzzaman et al., 1992). Little information
is available on the nature and off-odor generation in irradiated
meat, especially at low-dose irradiation (, 10 kGy).
The fundamental lipid oxidation mechanisms in irradiated
meat are expected to be the same as those in unirradiated. The
chemical conditions of irradiated meat, however, could be totally different from those of unirradiated. Irradiation would produce higher concentrations of hydroxyl radicals in meat because
more than 75% of muscle cells are composed of water (Thakur
and Singh, 1994). Lipid radicals would be formed via the free
radical reactions, and lipid hydroperoxides would be formed
when oxygen is available. We assume that both lipid oxidation
The authors are affiliated with the Dept. Of Animal Science, Iowa
State Univ., Ames, IA 50011-3150. Address inquiries to Dr. D.U.
Ahn.
and off-odor generation in irradiated meat are closely related to
hydroxyl radicals, but the relationship between off-odor generation and lipid oxidation status in irradiated meat is not known.
The oxidation of lipids in raw meat is closely related to the
antioxidant potential of muscle tissues. Vitamin E is a major
antioxidants in the cell membranes and protects the membrane
fatty acids and cholesterol from peroxidative damages caused
by reactive free radicals (Buckley et al., 1995; Liu et al., 1995).
The free radicals generated by irradiation can destroy antioxidants in muscle, reduce storage stability and increase off-flavor
production in meat (Thayer et al., 1993; Lakritz et al., 1995).
Supplementation of diets with vitamin E has increased vitamin
E concentration in muscle tissues, and its antioxidant effect in
the raw meat during storage has been well documented (Ajuyah
et al., 1993; Ahn et al., 1995; Winne and Dirinck, 1996; Morrissey et al., 1997). However, information on the antioxidant
effect of dietary tocopherols on irradiated and further processed
raw meat products is not well known.
The objectives of this research were to determine the effects
of dietary vitamin E supplementation on (1) the storage stability
of irradiated raw turkey meat as related to packaging and (2)
off-flavor development in irradiated raw turkey meat as measured by TBARS and total volatiles during storage.
MATERIALS & METHODS
Dietary treatments and sample preparations
Male large white turkeys were fed diets containing 0, 25, 50, 75, or
100 IU of dl-a-tocopheryl acetate (TA) per kg from 1 to 105 days of
age. At 105 days, two pens of turkeys previously fed those levels were
randomly assigned to diets containing 200, 400 or 600 IU of TA/kg diet.
Then each of the 200, 400, and 600 IU TA diets was fed to 8 pens of
poults, 8 poults per pen, from 105 to 122 days. Blood samples were
collected (one bird/pen) 1 day before slaughter. Plasma was obtained
from the blood samples and analyzed for vitamin E (a-tocopherol).
At the end of the trial, 2 birds per pen and the 8 turkeys on the 25
IU TA/kg of diet (total 64 birds) were randomly selected and slaughtered
following USDA guidelines (USDA, 1982). Carcasses were chilled in
ice water for 3 hr and drained in a cold room. Breast and leg muscles
were deboned from the carcasses 24 hr after slaughter. Skin and visible
fat were removed. Breast and leg meats from two birds from the same
pen were pooled (thus, 8 replications), and ground twice through a 3mm plate. Breast and thigh meat patties (' 100g each) were prepared
from each of the pooled ground breast and pooled leg meats representing
each pen.
Twelve breast and 12 thigh patties from each pen were used. Half (6
patties) of the breast and thigh patties were vacuum-packaged in oxygenimpermeable plastic films, and the other half were placed on laminated
foam trays and wrapped with oxygen permeable plastic film. The meats,
packaged in oxygen permeable or impermeable bags, were irradiated
with accelerated electrons by using a Linear Accelerator (Circe IIIR,
Thomson CSF Linac, Saint-Aubin, France) to a dose of 0- or 2.5-kGy
dose (127 kGy/min). The temperatures of the meat were kept at 2–47C
during irradiation, and after irradiation, they were stored up to 2 wk at
2–47C. Degrees of lipid oxidation and a-tocopherol concentrations in the
patties were measured after 0, 1, and 2 wk storage. Thiobarbituric acid
reactive substances (TBARS) were measured to determine the degree
and progress of lipid oxidation. A purge-and-trap unit was used to trap
volatiles responsible for flavor changes in the meat patties. Plasma and
tissue vitamin E levels were determined by HPLC (Shimadzu LC-10AS,
Kyoto, Japan) as described elsewhere (Sato-Salanova and Sell, 1996).
954—JOURNAL OF FOOD SCIENCE—Volume 62, No. 5, 1997
Table 1—Effect of dietary vitamin E on a-tocopherol content of plasma and
irradiated tissue samplesd
Leg
Breast
Plasma
Unirradiated Irradiated Unirradiated Irradiated
(IU/kg)
25
200
400
600
SEM
(µg/mL)
1.54d
5.33c
7.61b
9.59a
0.33
(µg/g)
0.29cy
1.01b
1.33by
1.57a
0.12
1.00cx
3.10bx
4.11bx
4.63ax
0.34
Day 7
Day 0
Dietary
vitamin E
0.46cx
1.35b
1.77ax
1.97a
0.13
Table 3—Effect of dietary vitamin E, irradiation, and storage time (at 4&C)
on TBARS of vacuum-packaged raw turkey leg meat pattiesc
0.25by
1.48ay
1.68ay
2.10ay
0.21
Dietary
vitamin E
(IU/kg)
25
200
400
600
SEM
abc Different letters within a column are significantly different (P , 0.05).
d Samples were irradiated at 2.5 kGy (avg) within 48 hr after slaughter (n 5 8).
xy Different letters within a row of same meat are significantly different (P , 0.05).
Unirradiated
Irradiated
0.24ay
0.13by
0.11by
0.09by
0.01
0.32ax
0.20bx
0.21bx
0.19bx
0.01
Unirradiated
Day 14
Irradiated
(mg MDA/kg meat)
0.22y
0.29ax
0.20x
0.16by
0.20
0.18b
0.19b
0.20
0.01
0.02
Unirradiated
Irradiated
0.98a
0.48b
0.40by
0.43b
0.04
1.11a
0.52b
0.44bx
0.43b
0.04
ab Different letters within a column are significantly different (P , 0.05).
c Samples were irradiated at 2.5 kGy (avg) within 48 hr after slaughter (n 5 8).
xy Different letters within a row of same storage period are significantly different (P ,
0.05.
Table 2—Effect of dietary vitamin E, irradiation, and storage time (at 4&C)
on TBARS of vacuum-packaged raw turkey breast meat pattiesc
Day 7
Day 0
Dietary
vitamin E
(IU/kg)
25
200
400
600
SEM
Unirradiated
Irradiated
0.22a
0.13by
0.10by
0.09by
0.02
0.28a
0.20bx
0.21bx
0.19bx
0.02
Unirradiated
Day 14
Irradiated
(mg MDA/kg meat)
0.33a
0.30a
0.11by
0.22bx
0.09by
0.19bx
0.09by
0.18bx
0.02
0.01
Unirradiated
Irradiated
0.75a
0.34by
0.31by
0.31by
0.04
0.77a
0.42bx
0.43bx
0.46bx
0.04
ab Different letters within a column are significantly different (P , 0.05).
c Samples were irradiated at 2.5 kGy (avg) within 48 hr after slaughter (n 5 8).
xy Different letters within a row of same storage period are significantly different (P ,
0.05).
Table 4—Effect of dietary vitamin E, irradiation, and storage time (at 4&C)
on TBARS of loosely packaged raw turkey breast pattiese
Day 7
Day 0
Dietary
vitamin E
(IU/kg)
25
200
400
600
SEM
Unirradiated
Irradiated
0.28a
0.18by
0.14c
0.09dy
0.01
0.30a
0.30ax
0.12b
0.19bx
0.03
Unirradiated
Day 14
Irradiated
(mg MDA/kg meat)
0.70ay
1.13ax
0.45by
0.77bx
0.26cy
0.40cx
0.27cy
0.42cx
0.03
0.07
Unirradiated
Irradiated
1.14ay
0.64by
0.23cy
0.21cy
0.07
1.69ax
0.84bx
0.35cx
0.41cx
0.09
a-d Different letters within a column are significantly different (P , 0.05).
e Samples were irradiated at 2.5 kGy (avg) and then stored at 4&C (n 5 8).
xy Different letters within a row of same storage period are significantly different (P ,
0.05).
Lipid oxidation
Lipid peroxidation was determined by the modified method of Buege
and Aust (1978). A 5-g meat sample was placed in a 50-mL test tube
and homogenized with 15 mL deionized distilled water (DDW) with a
Brinkman Polytron (Type PT 10/35, Westbury, NY) for 15 s at speed
7–8. Meat homogenate (1 mL) was transferred to a disposable test tube
(13 3 100 mm), and butylated hydroxyanisole (50 µL, 7.2%) and thiobarbituric acid/trichloroacetic acid (10 mM TBA/15% TCA) solutions (2
mL) were added. The mixture was vortexed and incubated in a boiling
water bath for 15 min to develop color. The samples were held in cold
water for 10 min and then centrifuged for 15 min at 2,000 3 g. The
absorbance of the resulting supernatant solution was determined at 531
nm vs a blank containing 1 mL DW and 2 mL TBA/TCA solution. The
TBARS numbers were expressed as mg malonaldehyde (MDA)/kg meat.
Statistical analysis
The experiment was designed primarily to determine the effects of
high-level dietary vitamin E on lipid peroxidation and off-odor production in irradiated raw meat samples with different oxygen availabilities.
The data for each irradiation and packaging condition were analyzed
independently by SAS software (SAS Institute, Inc., 1986). Analyses of
variance were conducted to test the effects of dietary vitamin E levels
within a storage time, and storage effect within a meat type. The StudentNewman-Keuls multiple range test was used to compare differences
among means. Mean values and standard errors of the mean (SEM) were
reported, and replications were used as the error terms for the calculations. Significance was defined at P , 0.05.
RESULTS & DISCUSSION
Volatiles analysis
Precept II and Purge-and-Trap Concentrator 3000 (Tekmar-Dohrmann, Cincinnati, OH) were used to purge and trap volatiles potentially
responsible for off-odors in irradiated meat. A Hewlett Packard GC
(Model 6890, Fullerton, CA) equipped with FID-detector was used to
analyze volatiles. Meat (2g) was weighed into a sample vial (40 mL),
capped tightly with a Teflon-lined open-mouth cap and placed in a refrigerated (37C) tray. Samples were transferred to sample holders by
using a robotic arm heated to 457C, deionized distilled water (10 mL)
was added and then purged with helium gas (40 mL/min) for 11 min.
Volatiles were trapped with a Tenax/Silica gel/Charcoal column (Tekmar-Dohrmann, Cincinnati, OH) and desorbed for 2 min at 2207C.
A split inlet (ratio, 39:1) was used to inject volatiles into a GC column
(DB-Wax capillary column, 0.53-mm i.d., 30m, and 1-µm film thickness;
Supelco, Bellefonte, PA), and sloped oven temperature conditions (307C
for 0.5 min, increased to 327C @507C/min, increased to 507C @407C/
min, increased to 1007C @307C/min, increased to 1807C @207C/min
and held for 2 min) were used. Inlet temperature was 807C, and detector
temperature was 2207C. Helium was used as carrier gas, and column
flow was 5.8 mL/min. Detector air, H2, and make-up gas (He) flows
were set at 300 mL/min, 30 mL/min, and 28 mL/min, respectively. Individual peaks were identified by retention times of volatile standards.
Standard kits (aldehyde-ketones, alcohols, hydrocarbons, and alkenes
C6-C10) were purchased from Chromatography Research Supplies (Addison, IL), and 9 aldehydes, 11 alcohols, 8 ketones, and 16 hydrocarbones standards were used to identify peaks in meat volatiles. The area
of each peak was integrated by ChemStation software (Hewlett Packard,
Fullerton, CA), and the total peak area (pA*sec) was reported as an
indicator of volatiles generated in the meat samples.
PLASMA AND MUSCLE VITAMIN E LEVELS increased with each
increment of dietary TA (Table 1), up to 3-fold when dietary
TA increased from 25 IU to 200 IU/kg diet. However, the effects of additional dietary TA were not linear. Leg muscle had
more than double the vitamin E of breast meat, but the vitamin
E in leg muscle was more susceptible to irradiation than that in
breast. Vitamin E in leg (' 60%) and in breast muscle (' 25%)
were destroyed by irradiation. Lakritz et al. (1995) reported the
loss of a-tocopherol in meat as a result of irradiation. Their
results indicated that the rate of tocopherol loss by irradiation
was greater in breast muscle than in leg meat. Also, the loss of
vitamin E in muscle by low-dose irradiation used by Lakritz et
al. (1995) was much greater than that we found.
The TBARS values in vacuum-packaged breast and leg meat
patties stored at 47C for 14 days (Tables 2, 3) showed both
irradiated and unirradiated breast meat patties prepared from the
turkeys fed diets containing 200 to 600 IU TA/kg were lower
than those fed the low-level TA diet (25 IU/kg). No differences
were found among TBARS values for meats from turkeys fed
200, 400, or 600 IU TA/kg. Irradiated meat, except for the 25
IU TA diet, had greater TBARS values than did unirradiated
meat in all three storage periods, but differences were small.
The TBARS values of irradiated and unirradiated breast meat
patties remained unchanged during the first 7-days storage at
47C in vacuum packaging. After 14-days storage at 47C, however, the TBARS of raw meat patties were two times higher
than those at 0 or 7 days (Table 2).
Volume 62, No. 5, 1997—JOURNAL OF FOOD SCIENCE—955
DIETARY VITAMIN E & LIPID OXIDATION/VOLATILES OF RAW TURKEY . . .
Table 5—Effect of dietary vitamin E, irradiation, and storage time (at 4&C)
on TBARS of loosely packaged raw turkey leg pattiese
Day 7
Day 0
Dietary
vitamin E
(IU/kg)
25
200
400
600
SEM
Unirradiated
Irradiated
0.52a
0.15by
0.18b
0.13by
0.03
0.63a
0.24bx
0.22b
0.21bx
0.04
Unirradiated
Day 14
Irradiated
(mg MDA/kg meat)
4.35a
4.30a
0.73by
1.40bx
0.56by
0.87bx
0.48by
0.92bx
0.18
0.33
Unirradiated
Irradiated
6.30ay
0.88by
0.79by
0.60by
0.18
8.83ax
2.13bx
1.21bx
1.35bx
0.33
a-d Different letters within a column are significantly different (P , 0.05).
e Samples were irradiated at 2.5 kGy (avg) and then stored at 4&C (n 5 8).
xy Different letters within a row of same storage period are significantly different (P ,
0.05).
Changes in TBARS values of vacuum packaged leg meat patties showed similar trends to those in breast meat (Table 3).
Antioxidant effects of dietary vitamin E became significant after
14-days storage at 47C. TBARS of vacuum-packaged turkey leg
meat from the high-level TA diets (200 to 600 IU/kg) were half
those of the 25 IU TA diet. Although large proportions of leg
muscle vitamin E were destroyed by irradiation (Table 1), differences in TBARS between irradiated and unirradiated leg meat
patties were slight (Table 3).
When patties were stored in oxygen permeable bags, however, oxidation rates (increasing TBARS), were much faster than
when patties were stored in vacuum-packaging bags (Tables 4
Fig. 1—GC profile of volatiles from an irradiated turkey thigh
meat patty after 7 days storage at 4&C.
and 5). Also, the antioxidant effect of dietary TA became more
obvious for meat in oxygen-permeable bags than that in the
vacuum-packaged bags. High-level dietary TA reduced peroxidation rate (P , 0.05) in loosely packaged breast meat patties
(Table 4), and high-level dietary TA (200 to 600 IU/kg) maintained TBARS of irradiated and unirradiated breast meat patties
below 1.0 during 14-days storage. The critical TBARS value for
oxidized flavor for sensitive consumers is around 1.0 (Gray et
al., 1996), and the baseline TBARS of cooked meat is determined by the conditions of the raw meat patties. Also, irradia-
Fig. 2—Effect of dietary vitamin E on production of total volatiles in irradiated and unirradiated turkey breast meat patties with
different packaging and storage times (dietary TA/kg diet: ▫, 25 IU; ●, 200 IU; ✧, 400 IU; X, 600 IU). abDifferent letters within a storage
day are significantly different (p , 0.05).
956—JOURNAL OF FOOD SCIENCE—Volume 62, No. 5, 1997
tion had a stronger effect on lipid oxidation of loosely packaged
than vacuum packaged breast meat patties. Irradiated breast
meat had higher TBARS than did unirradiated breast meat, and
the effects were significant (P , 0.05) for loosely packaged
patties stored 7 days or longer.
The development of lipid oxidation in loosely packaged leg
meat was faster than that of the breast meat. In general, intact
raw muscles are very resistant to lipid oxidation (Ahn et al.,
1993, 1995). However, the ground raw turkey meat was quite
unstable when oxygen was present, probably because oxygen
was an initiator or required for breakdown of primary products
of lipid oxidation. Iron contamination and disintegration of tissue structure the grinding may also have contributed to the high
TBARS. Leg meat patties from turkeys fed 25 IU TA /kg produced very high TBARS after 7-days storage, but feeding high
levels of dietary TA (200 to 600 IU/kg) maintained the TBARS
of leg meat patties below 1.0 during 14-days storage in presence
of oxygen. Irradiation increased the TBARS values of leg meat
patties after 7-days storage, but high levels of dietary TA (200
to 600 IU/kg) greatly reduced the lipid oxidation in irradiated
leg meat (Table 5). The prooxidant effect of irradiation became
critical only when the meat was stored in oxygen presence . 7
days. However, 200 IU or more of dietary TA controlled lipid
oxidation in irradiated and unirradiated raw meat patties during
storage, even with oxygen-permeable packaging.
Winne and Dirinck (1996) reported that muscle a-tocopherol
levels of chickens supplemented with 200 IU TA/kg diet were
6- to 7-fold higher than those fed the control diet (20 IU TA/
kg diet). Vitamin E supplementation had a beneficial effect on
the sensory and the oxidative stability of the meat. Wen et al.
(1996) reported that dietary supplementation of 300 or 600 IU
TA/kg diet reduced TBARS numbers in turkey burgers during
refrigerated and frozen storage. The National Research Council
(1994) recommendation for dietary vitamin E for growing turkeys is 12 IU/kg diet. However, research has indicated that at
least a 200-IU TA/kg diet is required to ensure antioxidant effects in turkey meat products during storage for 2 wk at 47C.
In the GC profile of volatiles from turkey meat (Fig. 1) all
peak areas were added and reported as total volatiles. When
stored in vacuum-packaging bags, the volatiles in irradiated and
unirradiated turkey breast meat patties from all dietary treatments remained unchanged for 7 days. After 14-days storage,
however, the total volatiles of irradiated and unirradiated breast
meat patties from turkeys fed 25 or 200 IU TA/kg increased,
whereas those from turkeys fed 400 and 600 IU TA/kg remained
unchanged (Fig. 2A, B). When packaged in oxygen permeable
bags, the effect of dietary vitamin E on total volatiles of breast
meat patties was less than in vacuum-packaged samples. Unirradiated turkey breast meat patties from turkeys fed 400 or more
IU TA/kg and irradiated turkey breast meat patties from 600 IU
TA/kg maintained relatively low volatiles levels for 7 days at
47C. After 14-days storage, however, none of the dietary TA
influenced the amount of total volatiles in turkey breast meat
patties (Fig. 2C, D).
Fig. 3—Effect of dietary vitamin E on production of total volatiles in irradiated and unirradiated turkey leg meat patties with different
packaging and storage time (dietary TA/kg diet: ▫, 25 IU; ●, 200 IU; ✧, 400 IU; X, 600 IU). abcDifferent letters within a storage day
are significantly different (P , 0.05).
Volume 62, No. 5, 1997—JOURNAL OF FOOD SCIENCE—957
DIETARY VITAMIN E & LIPID OXIDATION/VOLATILES OF RAW TURKEY . . .
Although tissue vitamin E contents in leg meat from turkeys
fed each of the dietary TA treatments were two times higher
than in breast meat (Table 1), the effects of dietary TA in controlling total volatiles of leg meat patties were less than that
observed with breast meat patties (Fig. 3). Dietary TA up to the
400-IU/kg diet had no effect on total volatiles in vacuum-packaged leg meat patties (Fig. 3A). However, unirradiated, vacuumpackaged leg meat patties from turkeys fed 600 IU TA/kg
maintained total volatiles at initial levels (0 day) for 7 days (Fig.
3B). Under oxygen-permeable packaging, the leg meat patties
from turkeys fed 200 to 600 IU TA/kg of diet produced less
total volatiles than those from turkeys fed 25 IU TA/kg of diet
during the first 7-days storage. After 14-days storage, however,
only the leg meat patties from turkeys fed . 400 IU TA/kg of
diet produced less total volatiles than those from turkeys fed 25
IU TA/kg of diet (Fig. 3C, 3D). In irradiated, loosely packaged
leg meat patties, 600 IU TA/kg was more effective than other
TA treatments in maintaining lower total volatiles after 7-days
storage (Fig. 3D). However, at this time the total volatiles of all
the meats may have been beyond the critical range. Irradiated
breast meat patties produced more total volatiles after 14 days
in vacuum-packaging, and the rest of the meat patties after 7
days storage.
As has been described by other researchers (Lynch et al.,
1991; Heath et al., 1990; Hashim et al., 1995), irradiated meat
produced a characteristic odor. Hansen et al. (1987) reported
that the levels of total volatiles in chicken skin increased with
irradiation dose. The effect of irradiation on total volatiles in
our study (2.5 kGy), however, was relatively slight and not consistent (Fig. 2, 3). Considering the low increase in total volatiles
but highly distinct off-odor observed when meat packages were
open for sample preparation (data not shown), the critical levels
for certain volatile components that produce off-odor in irradiated meat seem to be very low. Patterson and Stevenson (1995)
reported that dimethyltrisulfide, cis-3- and trans-6-nonenal,
oct-1-en-3-one, and bis(methylthio-)methane were the most potent and objectionable compounds in irradiated raw chicken.
Dietary vitamin E and ascorbate reduced the yields of irradiation
volatiles from the chicken muscles. However, we could not
identify those components in irradiated raw meat probably due
to limitations of the detector (FID) sensitivity.
CONCLUSION
DIETARY TA of . 200 IU/kg improved storage stability of irradiated and unirradiated turkey breast and leg meat patties. Production of total volatiles in turkey meat patties also was reduced
by dietary TA but only at 400 or 600 IU/kg. Irradiation increased lipid oxidation of raw turkey meat under oxygen exposure but had limited effects on total volatiles after 7 days or
longer storage at 47C.
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Ms received 3/24/97; revised 5/23/97; accepted 6/1/97.
Journal Paper No. J-17325 of the Iowa Agriculture and Home Economics Experiment Station, Ames, Iowa, Project No. 2794, and supported by Hoffman-LaRoche and Hatch Act.
958—JOURNAL OF FOOD SCIENCE—Volume 62, No. 5, 1997