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Impact of Light Source on Color and Lipid Oxidative Stabilities from a Moderately Color-Stable Beef Muscle during Retail Display

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Consumers’ purchasing decisions are heavily impacted by fresh meat color, which they consider an indicator of quality in a retail setting. The objectives of this study were to evaluate the impact of light source on surface color and lipid oxidation during retail display of fresh steaks from (SM), a beef muscle with moderate oxidative and color stabilities. Steaks ( = 240) from the SM ( = 20) were packaged on Styrofoam trays and overwrapped with oxygen-permeable polyvinyl chloride. Steaks were then assigned to 1 of 3 lighting treatments, high UV fluorescent (HFLO), low UV fluorescent (FLO), and light emitting diode (LED) to mimic current storage conditions with a variety of industry available fluorescent bulbs, and evaluate emerging lighting conditions with LED. Steaks were removed on retail display d 1, 3, 5, and 7 for evaluation of instrumental color (*, *, and * values), surface myoglobin redox forms, metmyoglobin reducing activity, and lipid oxidation. Light source influenced ( < 0.05) redness (* values), with HFLO-displayed steaks having greatest ( < 0.05) * values and LED-displayed steaks exhibiting lowest ( < 0.05) * values. Surface redness decreased ( < 0.05) over retail display day. Steaks displayed in HFLO and FLO had greater ( < 0.05) oxymyoglobin percentages than those displayed under LED, indicating that LED accelerated surface discoloration compared to HFLO and FLO lights. Metmyoglobin (MMb) percentages increased over retail display, with LED-exposed steaks having greater ( < 0.05) percentages of MMb than those displayed in HFLO and FLO. By d 7 of retail display, HFLO-exposed steaks had lower ( < 0.05) MMb percentages than the steaks displayed in both FLO and LED. Lighting type did not influence ( > 0.05) lipid oxidation in SM steaks, however, lipid oxidation increased ( < 0.05) over retail display. The findings indicated that light source influenced the color stability in SM steaks during retail display and that HFLO light can minimize surface discoloration in moderate color stability beef muscles.
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Meat and Muscle Biology™
Introduction
Consumer perception of fresh meat quality relies
heavily on color during retail display (Faustman and
Cassens 1990; Bekhit et al., 2001; Suman et al., 2014;
Holman et al., 2017). Numerous factors impact color
stability and oxidation in retail fresh meat; tempera-
ture (Jeremiah and Gibson, 2001), retail display length
(Martin et al., 2013), and light source (Cooper et al.,
2016; Steele et al., 2016). Therefore, the evaluation
of fresh meat color in various retail settings is neces-
sary to ensure continued consumer satisfaction as new
lighting technologies are developed.
Color and oxidative stabilities vary greatly be-
tween muscles in a beef carcass (McKenna et al.,
2005; Von Seggern et al., 2005; Seyfert et al., 2006;
Canto et al., 2016). McKenna et al. (2005) reported
that the beef semimembranosus (SM), a muscle iso-
Impact of Light Source on Color and
Lipid Oxidative Stabilities from a Moderately
Color-Stable Beef Muscle during Retail Display
Jade V. Cooper1, Surendranath P. Suman2, Bryon R. Wiegand1, Leon Schumacher3, and Carol L. Lorenzen1*
1Division of Animal Sciences, University of Missouri, Columbia, MO 65211, USA
2Department of Animal and Food Sciences, University of Kentucky, Lexington, KY 40546, USA
3Department of Agricultural Systems Management, University of Missouri, Columbia, MO 65211, USA
*Corresponding author. Email: LorenzenC@missouri.edu (C. L. Lorenzen)
Abstract: Consumers’ purchasing decisions are heavily impacted by fresh meat color, which they consider an indicator of qual-
ity in a retail setting. The objectives of this study were to evaluate the impact of light source on surface color and lipid oxidation
during retail display of fresh steaks from semimembranosus (SM), a beef muscle with moderate oxidative and color stabilities.
Steaks (n = 240) from the SM (n = 20) were packaged on Styrofoam trays and overwrapped with oxygen-permeable polyvinyl
chloride. Steaks were then assigned to 1 of 3 lighting treatments, high UV uorescent (HFLO), low UV uorescent (FLO), and
light emitting diode (LED) to mimic current storage conditions with a variety of industry available uorescent bulbs, and evalu-
ate emerging lighting conditions with LED. Steaks were removed on retail display d 1, 3, 5, and 7 for evaluation of instrumental
color (L*, a*, and b* values), surface myoglobin redox forms, metmyoglobin reducing activity, and lipid oxidation. Light
source inuenced (P < 0.05) redness (a* values), with HFLO-displayed steaks having greatest (P < 0.05) a* values and LED-
displayed steaks exhibiting lowest (P < 0.05) a* values. Surface redness decreased (P < 0.05) over retail display day. Steaks
displayed in HFLO and FLO had greater (P < 0.05) oxymyoglobin percentages than those displayed under LED, indicating
that LED accelerated surface discoloration compared to HFLO and FLO lights. Metmyoglobin (MMb) percentages increased
over retail display, with LED-exposed steaks having greater (P < 0.05) percentages of MMb than those displayed in HFLO and
FLO. By d 7 of retail display, HFLO-exposed steaks had lower (P < 0.05) MMb percentages than the steaks displayed in both
FLO and LED. Lighting type did not inuence (P > 0.05) lipid oxidation in SM steaks, however, lipid oxidation increased (P <
0.05) over retail display. The ndings indicated that light source inuenced the color stability in SM steaks during retail display
and that HFLO light can minimize surface discoloration in moderate color stability beef muscles.
Keywords: beef color, lighting, myoglobin, oxidation, semimembranosus
Meat and Muscle Biology 2:102–110 (2018) doi:10.22175/mmb2017.07.0040
Submitted 27 Jul. 2017 Accepted 18 Mar. 2018
This work was funded by the Missouri Beef Industry Council.
Published online May 3, 2018
103
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
American Meat Science Association. www.meatandmusclebiology.com
lated from the top round, is a muscle with moderate
color and oxidative stabilities based on objective color,
myoglobin concentrations, metmyoglobin reducing
activity, lipid oxidation, and other biochemical factors.
Cooper et al. (2016) documented that ground beef pat-
ties produced from the top round retained more redness
(a* values) over retail display under light emitting di-
ode (LED) lights in comparison to the patties displayed
under uorescent light sources.
The United States Department of Energy (US DOE,
2016) reported that by 2035, over 85% of lighting tech-
nologies will be LED compared to the 5% today. While
retail display conditions inuence the consumer qual-
ity perception of meat color (American Meat Science
Association, 2012), monitoring the impacts of the chang-
es in retail display conditions on meat color is of impor-
tance or to meat industry. Although Cooper et al. (2016)
reported that patties prepared from beef SM retained
redness longer under LED lights than under uorescent
lights, scientic information is limited on the impact of
lighting technologies on beef whole-muscle cuts with
moderate color and oxidative stabilities. We hypoth-
esized that the use of LED lights would decrease oxida-
tion of meat products in comparison to uorescent light
sources. Additionally, we assumed that low-UV uores-
cent and high-UV uorescent lights would impact oxida-
tion dierently from one another. Therefore, the objec-
tives of this study were to evaluate the impact of LED,
high-UV uorescent (HFLO), and low-UV uorescent
(FLO) light sources on surface color and lipid oxidation
of steaks from beef SM during the duration retail display.
Materials and Methods
Beef muscle fabrication and retail display
Beef top rounds (n = 20; USDA Select, Institutional
Meat Purchase Specication 168; USDA, 2014) were
purchased from a local vendor and delivered to the
University of Missouri meat laboratory in vacuum
packaging. Top rounds were aged for 20 d post-pack-
aging date at 1.1 ± 1°C to match industry averages
reported by Guelker et al. (2013), and the SM muscles
were removed to produce individual steaks (n = 240).
Twelve steaks (2.5 cm thick) were cut from each SM
muscle. Steaks were manually packaged on individual
Styrofoam® trays and overwrapped with oxygen-
permeable polyvinyl chloride (15,500 - 16,275 cm3/
m2/24 h oxygen transmission rate at 23°C).
Packaged steaks from various locations within the
SM muscle were then randomly assigned to 1 of 3 light-
ing treatments (HFLO, FLO, and LED) × retail display
d (1, 3, 5, or 7) combination, and were placed into 1 of 3
sliding door deli cases (TDBD-72–4, True Food Service
Equipment, O’Fallon, MO) equipped with its exclusive
light source (HFLO, FLO, or LED). Additionally, all
windows in each case were blacked out to avoid exter-
nal light inuence. Each deli case contained one shelf,
steaks were randomly placed within their assigned case.
Average light intensities for HFLO, FLO, and LED
bulbs were 289.97, 168.44, and 757.44 lux, respective-
ly. Light intensity was measured in 5 dierent locations
within each deli case by a GS-1150 Spectrophotometer
(Gamma Scientic, San Diego, CA). Temperature within
each case was monitored by factory-supplied thermom-
eters, and all 3 deli cases had temperature of 2 ± 1°C.
Proximate composition
Determination of fat percentage was done in tripli-
cate utilizing microwave drying and nuclear magnetic
resonance (NMR) as described in Dow et al. (2011)
with a CEM SMART Trac rapid fat analysis system
5 (Matthews, NC). Briey, 2 CEM sample pads were
heated and dried before 3.75 to 4.5 g of minced sample
from the remaining beef top round muscle (after steak
fabrication) was smeared across 1 pad and topped with
the remaining pad. Samples were dried using the CEM
Moisture/Solids Analyzer, and moisture was determined
on a dry weight basis. Following determination of mois-
ture, sample pads were wrapped in TRAC paper, inserted
into a CEM TRAC tube and was placed into the CEM
Rapid Fat Analyzer. Fat percentage of samples was then
determined on a dry basis using NMR and was ultimately
converted to a wet basis. Triplicate values were averaged
to determine overall fat percentages for each muscle.
Meat pH
Meat pH was determined according to American
Meat Science Association (2012). Briey, duplicate,
10-g sample of each remaining beef top round muscle
(after steak fabrication) was homogenized with 100
mL of distilled water. After homogenization, pH of
the homogenate was measured using a benchtop probe
(SevenCompact pH/Ion meter S220, tted with InLab
Versatile Pro probe, Mettler-Toledo AG Analytical,
Schwerzenbach, Switzerland).
Instrumental color
One steak from each SM and assigned light source
was removed from its package on the assigned retail
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
104American Meat Science Association. www.meatandmusclebiology.com
display d (1, 3, 5, or 7). L* (lightness), a* (redness),
and b* (yellowness) values were measured on 3 ran-
dom locations on the light-exposed steak surface using
a HunterLab MiniScan 45/0 LAV (Hunter Associates
Laboratory, VA) equipped with a D65 light source, 2.5
cm aperture, and 10° standard observer (American
Meat Science Association, 2012). Physical standards
were used to calibrate the HunterLab MiniScan each
day before the readings were taken. Instrumental
color readings were also utilized to calculate a/b ra-
tio, saturation index (SI), and hue angle (HA) values
(American Meat Science Association, 2012).
Myoglobin redox forms on the steak surface
Percentages of myoglobin (Mb) redox forms, i.e.,
deoxymyoglobin (DMb), oxymyoglobin (OMb), and
metmyoglobin (MMb), on steak surfaces were de-
termined at each retail display time point (American
Meat Science Association, 2012). Reectance was
measured at wavelengths of 470, 530, 570, and 700
nm on the light-exposed steak surfaces employing a
HunterLab MiniScan 45/0 LAV (Hunter Associates
Laboratory, VA), and the percentage of Mb redox
forms were determined utilizing the equations accord-
ing to American Meat Science Association (2012).
Myoglobin content
Duplicate 2.5 g minced steak surface samples (0.64-
cm deep) were homogenized for 60 s using a Polytron
homogenizer (Polytron 10–35 GT, Kinematica, Bohemia,
NY) in 22.5 mL of ice-cold sodium phosphate buer, pH
6.8, for 90 s. Homogenate was then ltered through lter
paper with particle retention of 4 to 8 μm and a ow rate
of 25 mL/min (Fisherbrand P4 Grade, Fisher Scientic,
Suwanee, GA) into clean tubes. Filtrate absorbance
was read at 525 nm on a Genesys 20 spectrophotometer
(Thermo Fisher Scientic, Waltham, MA). Myoglobin
concentrations were calculated utilizing the equation
provided in American Meat Science Association (2012).
Metmyoglobin reducing ability
Metmyoglobin reducing ability was measured us-
ing a method described by Sammel et al. (2002). Triplicate
cubes, 4-cm × 4-cm × 0.64-cm deep, from the center of
each steaks surface were removed on each day of desig-
nated retail display for all light treatments. Upon remov-
al, samples were submerged in 0.3% sodium nitrite solu-
tion for 20 min to induce MMb formation. After 20 min,
samples were removed from the solution, blotted dry,
and vacuum sealed (Multivac, Chamber Machine P200,
Kansas City, MO) in individual packages. Readings of
each sample were taken immediately after packaging
utilizing a HunterLab MiniScan in triplicate to obtain
reectance data. Samples were incubated at room tem-
perature for 120 min to induce MMb reduction. After
incubation, samples were rescanned in triplicate with a
HunterLab MiniScan. Surface MMb values were calcu-
lated using K/S ratios and formulas provided in American
Meat Science Association (2012). Metmyoglobin reducing
ability was calculated using the equation below.
% MRA =
100 × (Pre-incubation % metmyoglobin –
Post incubation % metmyoglobin)
Pre-incubation % metmyoglobin
Lipid oxidation
Lipid oxidation was determined utilizing the distilla-
tion method to analyze thiobarbituric acid reactive sub-
stances (TBARS) as described in Tarladgis et al. (1960)
with modications found in Fernando et al. (2013).
Duplicate 5 g steak samples were minced and homog-
enized (Polytron 10–35 GT, Kinematica) with 25 mL of
distilled water. Homogenate was then poured into a 250
mL Kjeldahl ask and blending tubes were rinsed with
an additional 25 mL distilled water and transferred into
the same ask. Two drops of antifoam solution (Antifoam
BTM Silicone Emulsion, Thermo Fisher Scientic) along
with 2.5 mL 4 N HCl to balance sample pH between 1.5
to 1.6 were added to the ask immediately before distilla-
tion. Flasks were placed into controlled heating elements
(Fisher Scientic, Pittsburg, PA) and 25 mL of sample
was distilled through a water-cooled distillation appara-
tus. After distillation, 5 mL of sample was pipetted into
a glass tube containing 5 mL thiobarbituric acid reagent
and vortexed individually. Tubes were then placed into
a boiling water bath for 35 min. Immediately following
removal from the water bath, tubes were submerged into
an ice bath for 10 min. Color absorbance was measured at
538 nm using a Genesys 20 spectrophotometer (Thermo
Fisher Scientic). Values for TBARS concentrations
were determined by obtaining the average absorption of
the duplicate sample readings and mg/kg of malonalde-
hyde was determined using the K value of 7.8 (Tarladgis
et al., 1960; American Meat Science Association, 2012).
Statistical analyses
The experimental design was a randomized complete
block design with twenty replicates. Data were analyzed
with the model including xed eects of light (HFLO,
105
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American Meat Science Association. www.meatandmusclebiology.com
FLO, or LED), length of retail display (1, 3, 5, or 7 d), and
all possible interactions. Analyses of instrumental color,
myoglobin redox forms, myoglobin content, metmyo-
globin reducing activity, and lipid oxidation were done
using the GLIMMIX function of SAS (SAS Version 9.4,
SAS Inst. Inc., Cary, NC) to obtain LS means and stan-
dard error estimates. Signicance was determined at P
< 0.05 level. The PROC CORR procedure of SAS was
then used to generate correlations.
Results and Discussion
Meat ph and proximate composition
Average pH values of SM steaks (Table 1) were
similar to those reported by Von Seggern et al. (2005)
and King et al. (2011a). Fat content of SM steaks were
lower than those reported by Von Seggern et al. (2005).
Variations in fat and moisture concentrations of fresh
beef can impact objective color measurements as in-
creased fat content can increase L* values (Raines et
al., 2009; Martin et al., 2013; Garner et al., 2014).
Instrumental color
The L* values in SM steaks displayed under various
light sources demonstrated dierences (P < 0.05), with
LED-displayed steaks having the greatest L* value (great-
er lightness; Table 2). Steele et al. (2016) reported no dif-
ferences in L* values for SM steaks under FLO and LED
light sources. Additionally, Cooper et al. (2017) found no
dierences in L* values for steaks from the Triceps bra-
chii, a muscle with low oxidative and color stability, dis-
played under uorescent and LED lights during retail dis-
play. Retail display time also played a role in L* values in
steaks from the SM; L* values decreased (P < 0.05) over
retail display (Table 3). This nding agrees with those of
King et al. (2011a), who observed a decrease in L* values
of beef SM steaks from d 0 to 6 of retail display. Khliji et
al. (2010) found that an L* value of 35 and higher contrib-
uted to an acceptable meat color according to consumers.
Table 1. Proximate composition and pH values of beef
semimembranosus (n = 20) steaks (n = 240)
Parameter Average Minimum Maximum SD1
pH 5.41 5.02 6.24 0.33
Fat, % 2.10 0.43 5.53 1.33
Moisture, % 74.86 70.04 79.00 2.30
1Standard deviations of mean values.
Table 2. Eect of display light source on color traits
of beef semimembranosus (n = 20) steaks (n = 240)
Parameter
Light source1
SEM
P-value2
HFLO FLO LED
L* 41.83ab 41.14b42.36a0.46 0.0335
a* 20.85a20.11ab 19.37b0.43 0.0031
b* 19.59 19.37 19.20 0.35 0.5434
a/b31.07a1.04a1.00b0.02 0.0006
SI428.68a28.02ab 27.37b0.51 0.0400
HA543.48b44.43a45.30a0.45 0.0004
DMb64.68a4.20b4.53ab 0.18 0.0229
OMb756.59a56.45a55.95b0.16 0.0002
Mb84.39 4.29 4.24 0.11 0.3981
MRA918.64 19.04 15.53 2.11 0.1928
TBARS10 1.23 1.19 1.31 0.08 0.3197
a,bMeans without a common superscript dier (P < 0.05).
1HFLO = high UV uorescent; FLO = low UV uorescent; LED = light
emitting diode.
2P-value of LS Means.
3a/b = a/b ratio.
4SI = Saturation Index.
5HA = Hue Angle.
6DMb = Deoxymyoglobin (%).
7OMb = Oxymyoglobin (%).
8Mb = Myoglobin concentration (mg/g).
9MRA = Metmyoglobin reducing ability (%).
10TBARS = Thiobarbituric acid reactive substances (mg/kg).
Table 3. Eect of retail display day on color traits of
beef semimembranosus (n = 20) steaks (n = 240)
Parameter
Retail display day
SEM
P-value1
1357
L* 42.91a42.18ab 41.49bc 40.52c0.57 0.0001
a* 24.52a20.34b19.35c16.25d0.50 < 0.0001
b* 21.02a19.73b19.24b17.57c0.41 < 0.0001
a/b21.18a1.06b0.98c0.92d0.02 < 0.0001
SI332.33a28.05b27.68b24.03c0.60 < 0.0001
HA440.55d43.46c45.85b47.75a0.52 < 0.0001
DMb55.82a4.85b3.82c3.39d0.20 < 0.0001
OMb656.70a56.58a56.46a55.59b0.19 < 0.0001
Mb74.40 4.34 4.25 4.23 0.13 0.5078
MRA827.11a15.39b16.06b12.38b2.43 < 0.0001
TBARS90.47d1.06c1.49b1.95a0.09 < 0.0001
a-dMeans without a common superscript dier (P < 0.05).
1P-value of LS Means.
2a/b = a/b ratio.
3SI = Saturation Index.
4HA = Hue Angle.
5DMb = Deoxymyoglobin (%).
6OMb = Oxymyoglobin (%).
7Mb = Myoglobin concentration (mg/g).
8MRA = Metmyoglobin reducing ability (%).
9TBARS = Thiobarbituric acid reactive substances (mg/kg).
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
106American Meat Science Association. www.meatandmusclebiology.com
All L* values in this study were above the threshold for
meat color acceptability based on L* values.
Surface redness (a* values) diered (P < 0.05) be-
tween light sources (Table 2). Greater a* values indi-
cate a more red, consumer-desirable product. High UV
uorescent -displayed steaks demonstrated greater (P <
0.05) redness than the LED-exposed steaks. This nding
indicated that the use of a HFLO light source promoted
greater redness retention than LED light sources. These
ndings agree with those found in Cooper et al. (2017)
who reported higher a* values in steaks produced from
the Triceps brachii displayed under HFLO lights in com-
parison to those kept under LED light sources during retail
display. Steele et al. (2016) reported that on d 0 of retail
display, a* values were greater for SM steaks displayed
under LED lights than under uorescent lights. However,
for the duration of retail display, Steele et al. (2016) re-
ported no dierences in a* values between steaks from
the SM displayed under uorescent and LED light sourc-
es. Display case temperatures in Steele et al. (2016) were
slightly lower (LED display case 0.84°C; uorescent dis-
play case 1.53°C) than those in the present study, which
could have impacted the rate of discoloration. Decreases
in a* values are indicative of discoloration of fresh meat
products by a loss of redness on the surface of the prod-
uct (Rogers et al., 2014). Values for a* decreased (P <
0.05) with increasing retail display time (Table 3). This
nding is supported by the previous studies (McKenna
et al., 2005; King et al., 2011a; Colle et al., 2016; Cooper
et al., 2016; Steele et al., 2016; Cooper et al., 2017) that
observed decreases in a* values over retail display time
for fresh beef products under uorescent light sources.
Holman et al. (2017) reported that an a* value of 14.5 is
considered the acceptable threshold for consumer accept-
ability of fresh beef. Accordingly, SM steaks in the pres-
ent study were acceptable to consumers under all light
treatments and for the entire duration of retail display.
No dierences (P > 0.05) in b* values were found
between steaks displayed in all 3 light sources (Table
2). However, b* values decreased (P < 0.05) through-
out the duration of retail display (Table 3). King et
al. (2011a) also reported a similar trend in b* values
for SM steaks during retail display. Similarly, Cooper
et al. (2017) found that b* values decreased over the
duration of 7 d of retail display in steaks produced
from the Triceps brachii. Previous research has also
reported a decrease in b* values over 9 d of retail stor-
age in steaks from the Longissimus lumborum, a color
stable muscle (Joseph et al., 2012; Canto et al., 2016).
The a/b ratios were lower (P < 0.05) for SM
steaks displayed under LED lights compared to those
displayed with HFLO and FLO lights (Table 2).
Decreases in a/b ratio values indicate a loss of red-
ness (American Meat Science Association, 2012).
This nding indicated greater discoloration in steaks
displayed with LED lights than those displayed under
HFLO and FLO. Additionally, the a/b ratios decreased
(P < 0.05) over 7 d of retail display (Table 3).
Mimicking trends in a* values, SI diered (P < 0.05)
between light sources, with HFLO steaks having greater
SI values (P < 0.05) than steaks displayed with both FLO
and LED light sources (Table 2). This indicated greater
amounts of redness retention in SM steaks displayed un-
der HFLO lights than in SM steaks under FLO and LED
lights. Steele et al. (2016) reported greater SI for SM
steaks displayed under LED light than those displayed
under uorescent light on d 0 of retail display, whereas
for the remainder of the 4-d retail display no dierences
were observed between the LED and uorescent light
sources. The SI decreased (P < 0.05) over retail display
(Table 3), agreeing with multiple previous reports (King
et al., 2011a; Steele et al., 2016; Cooper et al., 2016) in-
dicating a decrease in surface color intensity over time.
Hue angle increases as discoloration increases
(Trinderup and Kim, 2015). The SM steaks displayed
with HFLO lights exhibited lower (P < 0.05) HA than
their counterparts under FLO and LED (Table 2), in-
dicating that the use of HFLO bulbs minimizes discol-
oration in retail display. Length of retail display also
impacted (P < 0.05) HA values, with HA increasing
over retail display (Table 3). These results agree with
previous investigations (King et al., 2011a; Cooper et
al., 2016; Steele et al., 2016).
Instrumental color data suggested that the use of
HFLO light in retail display promoted a greater amount
of surface red color retention in comparison to FLO or
LED lights in beef SM steaks, as indicated by a* value,
a/b ratios, SI, and HA. Cooper et al. (2017) found that
the use of HFLO light sources promoted greater red-
ness retention in beef steaks from the Triceps brachii
compared to steaks under LED and FLO retail display.
Steele et al. (2016) reported higher a* and SI values for
SM steaks on d 0 of retail display but reported no dier-
ences between light sources for the duration of display.
Surface myoglobin redox forms
Light source inuenced (P < 0.05) the DMb percent-
age in SM steaks, with the steaks displayed under HFLO
demonstrating greater (P < 0.05) DMb levels than those
under LED (Table 2). During retail display, DMb percent-
age decreased (P < 0.05) in steaks (Table 3); this nding
was expected as oxygen exposure during retail display al-
lows for the oxygenation of DMb to OMb (Faustman and
107
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
American Meat Science Association. www.meatandmusclebiology.com
Cassens, 1990). The OMb is the bright cherry-red redox
form that provides the consumer-desirable color to fresh
beef products. As oxidation progresses, OMb percentage
decreases with a concomitant increase in surface discol-
oration due to the formation of MMb (Suman and Joseph,
2013; Mancini and Ramanathan, 2014). Oxymyoglobin
percentage of SM steaks diered (P < 0.05) between
light sources (Table 2); steaks displayed under HFLO
and FLO had greater (P < 0.05) OMb percentages than
those displayed in LED. As previously stated, a* values
for steaks displayed under LED light sources were lower
than those displayed under HFLO and FLO light sources
(Table 2). These ndings indicate that the use of LED
light sources in retail display promotes discoloration via
loss of redness in SM steaks at greater degree than both
high and low UV-uorescent light. Oxymyoglobin per-
centage was not aected (P > 0.05) through d 5 of display,
but decreased (P < 0.05) on d 7 (Table 3), indicating that
SM steaks retained redness through d 5 of retail display.
As expected with the decrease in OMb percentage, the
MMb percentage increased (P < 0.05) in SM steaks under
all light treatments over retail display (Fig. 1). Decreasing
a* values reported over the duration of retail display for
steaks from the SM is an indicator of the discoloration
brought on by MMb formation (Table 3). By d 5, LED-
displayed steaks had greater (P < 0.05) MMb percentages
than both HFLO and FLO displayed steaks, indicating
more severe discoloration occurring in steaks displayed
with LED lights compared to both uorescent light sourc-
es. On d 7 of retail display, both LED and FLO displayed
steaks had greater (P < 0.05) MMb percentages than those
displayed with HFLO lights. Greene et al. (1971) estab-
lished a threshold of 40% surface MMb formation to il-
licit consumer discrimination against beef due to discolor-
ation. These ndings indicate that the use of HFLO light
minimizes Mb oxidation and surface discoloration in SM
steaks during retail display. Cooper et al. (2017) report-
ed that the use of HFLO light sources promoted greater
amounts of redness retention in comparison to LED light
sources in steaks produced from the Triceps brachii.
Myoglobin content
Concentration of myoglobin in a muscle can be
used as an indicator of oxidative metabolism (King et al.,
2011a). As expected, no dierences (P > 0.05) were ob-
served in Mb concentrations of steaks displayed in dier-
ent lighting (Table 2). Retail display time also did not im-
pact (P > 0.05) Mb concentrations (Table 3). Myoglobin
concentrations in this study were similar to those previ-
ously reported (McKenna et al., 2005; King et al., 2011a).
Metmyoglobin reducing activity
Metmyoglobin reducing activity attributes to the
color stability of individual muscles by the reduction of
metmyoglobin to its ferrous redox forms (McKenna et
al., 2005; Nair et al., 2016). Light source did not impact
(P > 0.05) metmyoglobin reducing activity of SM steaks
(Table 2). However, retail display time inuenced (P <
0.05) metmyoglobin reducing activity, and metmyoglo-
bin reducing activity values were greater (P < 0.05) on
d 1 than values over the remaining days of retail display
(Table 3). Moderate oxidative and color stabilities of
Figure 1. Eect of light source1 and retail display on metmyoglobin contents in beef semimembranosus (n = 20) steaks (n = 240). 1HFLO = high UV
uorescent; FLO = low UV uorescent; LED = light emitting diode. a-dData without a common superscript dier (P < 0.05).
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
108American Meat Science Association. www.meatandmusclebiology.com
beef SM (McKenna et al., 2005) may be attributed to the
lack of variation of metmyoglobin reducing activity val-
ues between d 3 and 7 of retail display. Wu et al. (2015)
reported that metmyoglobin reducing activity exhibited
no changes in beef semitendinosus steaks during retail
display over 5 d. Whereas, Kim et al. (2006) reported
decreasing metmyoglobin reducing activity values over 7
d of retail display in steaks from the Longissimus lumbo-
rum and SM. These variations in reducing ability could
be attributed to the rate of depletion of NADH pools
within each muscle (Bekhit and Faustman, 2005; Kim et
al., 2006; King et al., 2011b; Wu et al., 2015).
Lipid oxidation
Light treatment did not inuence (P > 0.05) lipid
oxidation in SM steaks (Table 2). The TBARS val-
ues for all light treatments were below the detectable
rancidity threshold value of 2.0 (Campo et al., 2006).
Since beef SM has moderate color and oxidative stabil-
ity (McKenna et al., 2005), these results were expect-
ed. Cooper et al. (2016) found no dierences in lipid
oxidation in ground patties from beef SM displayed
under LED and uorescent lighting. In contrast, Steele
et al. (2016) observed that SM steaks displayed under
LED lights demonstrated greater lipid oxidation than
those under uorescent light sources throughout retail
display. Cooper et al. (2017) reported higher TBARS
values in steaks from the Triceps brachii displayed un-
der LED lights as opposed to HFLO light sources. In
the present study, lipid oxidation increased (P < 0.05)
with the retail display time (Table 3), and these results
agree with the previous studies (Martin et al., 2013;
Colle et al., 2016; Cooper et al., 2016; Steele et al.,
2016; Cooper et al., 2017) in fresh beef products. The
results of the present study indicate that retail display
time had a greater impact than light source on lipid
oxidation in beef SM steaks.
Relationship between color
traits and lipid oxidation
Strong negative correlations were observed be-
tween TBARS and a* values indicating that increas-
es in lipid oxidation results in product discoloration
(Table 4). Moderate negative correlations occurred
between TBARS and b* values and DMb contents.
Conversely, a strong positive correlation was noted
between TBARS and MMb levels. These trends indi-
cate that an increase in TBARS values correlate with
a decrease in redness. Strong relationships between
lipid oxidation and discoloration in fresh meat prod-
ucts have been documented (Faustman and Cassens,
1990; Lynch et al., 1999; Renerre, 2000; Faustman et
al., 2010). As expected, the increases in TBARS val-
ues positively correlated with MMb percentage; indi-
Table 4. Correlation among various color characteristics and biochemical attributes in beef semimembranosus
(n = 20) steaks (n = 240)
Parameter L* a* b* DMb OMb MMb TBARS Mb MRA pH
L* 1.00
a* -0.28*** 1.00
b* 0.08 0.73*** 1.00
DMb1-0.03 0.58 0.17 1.00
OMb2-0.13* 0.44 -0.45 -0.23** 1.00
MMb30.12 -0.83 -0.45 -0.56*** -0.31 1.00
TBARS40.15* -0.72*** -0.45*** -0.56*** -0.31 0.72*** 1.00
Mb5-0.13* 0.01 -0.08 -0.11 0.14* 0.01 0.05 1.00
MRA6-0.50*** 0.51*** 0.24*** 0.31*** 0.09 -0.34*** -0.26*** -0.001 1.00
pH -0.54*** 0.20* -0.11 0.27*** -0.10 -0.18* -0.08 0.06 0.40*** 1.00
*P < 0.05.
**P < 0.001.
***P < 0.0001.
1DMb = Deoxymyoglobin (%).
2OMb = Oxymyoglobin (%).
3MMb = Metmyoglobin (%).
4TBARS = Thiobarbituric acid reactive substances (mg/kg).
5Mb = Myoglobin concentration (mg/g).
6MRA = Metmyoglobin reducing ability (%).
109
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
American Meat Science Association. www.meatandmusclebiology.com
cating that lipid oxidation and discoloration progress
simultaneously in fresh beef products.
Metmyoglobin reducing activity demonstrated
moderate negative correlations with L* and weak nega-
tive correlations with both MMb content and TBARS
values. Results indicate that increases in metmyoglobin
reducing activity correlate with decrease in TBARS
and MMb concentrations. These results are in agree-
ment with multiple ndings of increased metmyoglobin
reducing activity levels in muscles with greater color
and oxidative stabilities (Joseph et al., 2012; Canto et
al., 2016). Moderate positive correlations occurred be-
tween metmyoglobin reducing activity and a* values.
McKenna et al. (2005) also found a positive correla-
tion between metmyoglobin reducing activity and a*
values in numerous bovine muscles. As metmyoglobin
reducing activity is an indirect measurement of color
stability, positive correlations with a* are expected as
an increase in redness would be an indicator of color
retention (King et al., 2011b; Joseph et al., 2012).
Conclusions
Light source impacted surface redness retention, dis-
coloration and Mb oxidation of steaks produced from the
SM during retail display. Data indicated that while the use
of HFLO lights promoted a greater amount of surface red-
ness retention in comparison to LED lights, all steaks were
above the determined threshold for a* acceptability within
each light treatment. However, SM steaks displayed under
LED reached the threshold of consumers to detect brown
color as indicated by percent surface MMb on retail dis-
play d 5 compared to HFLO and FLO lighting sources
which did not reach the threshold until retail display d 7.
Light sources used in retail display may not have an im-
pact on consumer purchase preference in steaks produced
from muscles with moderate color stability.
Literature Cited
American Meat Science Association. 2012. Meat Color Measurement
Guidelines. Amer. Meat Sci. Assoc. Champaign, IL.
Bekhit, A. E. D., G. H. Geesink, J. D. Morton, and R. Bickerstae.
2001. Metmyoglobin reducing activity and colour stabil-
ity of ovine longissimus muscle. Meat Sci. 57:427–435.
doi:10.1016/S0309-1740(00)00121-2
Bekhit, A. E., and C. F. Faustman. 2005. Metmyoglobin reducing ac-
tivity. Meat Sci. 71:407439. doi:10.1016/j.meatsci.2005.04.032
Campo, M. M., G. R. Nute, S. I. Hughes, M. Enser, J. D. Wood, and R.
I. Richardson. 2006. Flavour perception of oxidation in beef. Meat
Sci. 72:303311 . doi:10.1016/j.meatsci.2005.07.015
Canto, A. C. V. C. S., B. R. C. Costa-Lima, S. P. Suman, M. L.
G. Monteiro, F. M. Viana, A. P. A. A. Salim, M. N. Nair, T.
J. P. Silva, and C. A. Conte-Junior. 2016. Color attributes
and oxidative stability of longissimus lumborum and psoas
major muscles from Nellore bulls. Meat Sci. 121:1926.
doi:10.1016/j.meatsci.2016.05.015
Colle, M. J., R. P. Richard, K. M. Killinger, J. C. Bohlscheid, A. R.
Gray, W. I. Loucks, R. N. Day, A. S. Cochran, J. A. Nasados,
and M. E. Doumit. 2016. Inuence of extended aging on
beef quality characteristics and sensory perception of steaks
from the biceps femoris and semimembranosus. Meat Sci.
119:110117. doi:10.1016/j.meatsci.2016.04.028
Cooper, J. V., S. P. Suman, B. R. Wiegand, L. Schumacher, and C. L.
Lorenzen. 2017. Light source inuences color stability and lipid
oxidation from low color stability beef triceps brachii muscle. Meat
and Musc. Biol. 1:149156. doi:10.22175/mmb2017.06.0029
Cooper, J. V., B. R. Wiegand, A. B. Koc, L. Schumacher, I. Gruën,
and C. L. Lorenzen. 2016. Impact of contemporary light
sources on oxidation of fresh ground beef. J. Anim. Sci.
94:44574462. doi:10.2527/jas.2016-0728
Dow, D. L., B. R. Wiegand, M. R. Ellersieck, and C. L. Lorenzen. 2011.
Prediction of fat percentage within marbling scores on beef lon-
gissimus muscle using three dierent fat determination methods. J.
Anim. Sci. 89:11731179. doi:10.2527/jas.2010-3382
Faustman, C., and R. G. Cassens. 1990. The biochemical basis for
discoloration in fresh meat: A review. J. Muscle Foods. 1:217
243. doi:10.1111/j.1745-4573.1990.tb00366.x
Faustman, C., Q. Sun, R. Mancini, and S. Suman. 2010. Myoglobin
and lipid oxidation interactions: Mechanistic bases and control.
Meat Sci. 86:8694. doi:10.1016/j.meatsci.2010.04.025
Fernando, L. N., E. P. Berg, and I. U. Grün. 2013. Quantitation of
hexanal by automated SPME for studying dietary inuences
on the oxidation of pork. J. Food Compos. Anal. 16(2):179
188. doi:10.1016/S0889-1575(02)00173-4
Garner, C. M., J. A. Unruh, M. C. Hunt, E. A. E. Boyle, and T. A.
Houser. 2014. Eects of subprimal type, quality grade, and
aging time on display color of ground beef patties. Meat Sci.
98(2):301309. doi:10.1016/j.meatsci.2014.05.004
Greene, B. E., I. Hsin, and M. W. Zipser. 1971. Retardation of oxi-
dative color changes in raw ground beef. Food Sci. 36(6):940
942. doi:10.1111/j.1365-2621.1971.tb15564.x
Guelker, M. R., A. N. Haneklaus, J. C. Brooks, C. C. Carr, R. J. Delmore,
D. B. Grin, D. S. Hale, K. B. Harris, G. G. Hilton, D. D. Johnson,
C. L. Lorenzen, R. J. Maddock, J. N. Martin, R. K. Miller, K. L.
Nicholson, C. R. Raines, D. L. VanOverbeke, L. Vedral, B. E.
Wasser, and J. W. Savell. 2013. National Beef Tenderness Survey-
2010: Warner-Bratzler shear-force values and sensory panel rat-
ings for beef from US retail and foodservice establishments. J.
Anim. Sci. 91:10051014. doi:10.2527/jas.2012-5785
Holman, B. W. B., R. J. van de Ven, Y. Mao, C. E. O. Coombs, and
D. L. Hopkins. 2017. Using instrumental (CIE and reectance)
measures to predict consumers’ acceptance of beef colour. Meat
Sci. 127:5762. doi:10.1016/j.meatsci.2017.01.005
Jeremiah, L. E., and L. L. Gibson. 2001. The inuence of storage
temperature and storage time on color stability, retail proper-
ties, and case-life of retail-ready beef. Food Res. Int. 34:815
826. doi:10.1016/S0963-9969(01)00104-1
Meat and Muscle Biology 2018, 2:102-110 Cooper et al. Light Source and Fresh Beef Color
110American Meat Science Association. www.meatandmusclebiology.com
Joseph, P., S. P. Suman, G. Rentfrow, S. Li, and C. M. Beach. 2012.
Proteomics of muscle-specic beef color stability. J. Agric.
Food Chem. 60(12):31963203. doi:10.1021/jf204188v
Khliji, S., R. van de Ven, T. A. Lamb, M. Lanza, and D. L. Hopkins.
2010. Relationship between consumer ranking of lamb colour
and objective measurements of color. Meat Sci. 85:224229.
doi:10.1016/j.meatsci.2010.01.002
Kim, Y. H., M. C. Hunt, R. A. Mancini, M. Seyfert, T. M. Loughin,
and D. H. Kropf. 2006. Mechanism for lactate-color stabi-
lization in injection-enhanced beef. J. Agric. Food Chem.
54(20):7856-7862. doi:10.1021/jf061225h
King, D. A., S. D. Shackelford, and T. L. Wheeler. 2011a.
Relative contributions of animal and muscle eects to varia-
tion in beef lean color stability. J. Anim. Sci. 89:14341451.
doi:10.2527/jas.2010-3595
King, D. A., S. D. Shackelford, A. B. Rodriguez, and T. L. Wheeler.
2011b. Eect of time of measurement on the relationship between
metmyoglobin reducing activity and oxygen consumption to in-
strumental measures of beef longissimus color stability. Meat Sci.
87(1):2632. doi:10.1016/j.meatsci.2010.08.013
Lynch, M. P., J. P. Kerry, D. J. Buckley, C. Faustman, and P. A. Morrissey.
1999. Eect of dietary vitamin e supplementation on the colour
and lipid stability of fresh, frozen and vacuum-packaged beef.
Meat Sci. 52:9599. doi:10.1016/S0309-1740(98)00153-3
Mancini, R. A., and R. Ramanathan. 2014. Eects of postmortem stor-
age time on color and mitochondria in beef. Meat Sci. 98:6570.
doi:10.1016/j.meatsci.2014.04.007
Martin, J. N., J. C. Brooks, T. A. Brooks, J. F. Legako, J. D. Starkey,
S. P. Jackson, and M. F. Miller. 2013. Storage length, storage
temperature, and lean formulation inuence the shelf-life
and stability of traditionally packaged ground beef. Meat Sci.
95:495502. doi:10.1016/j.meatsci.2013.05.032
McKenna, D. R., P. D. Mies, B. E. Baird, K. D. Pfeier, J. W.
Ellebracht, and J. W. Savell. 2005. Biochemical and physical
factors aecting discoloration characteristics of 19 bovine mus-
cles. Meat Sci. 70:665682. doi:10.1016/j.meatsci.2005.02.016
Nair, M. N., S. P. Suman, M. K. Chatli, S. Li, P. Joesph, C. M.
Beach, and G. Rentfrow. 2016. Proteome basis for intramus-
cular variation in color stability of beef semimembranosus.
Meat Sci. doi:10.1016/j.meatsci.2015.11.003
Raines, C. R., M. C. Hunt, and J. A. Unruh. 2009. Cow biologi-
cal type aects ground beef color. Meat Sci. 83(4):752758.
doi:10.1016/j.meatsci.2009.08.032
Renerre, M. 2000. Oxidative processes and myoglobin. In: E. A.
Decker, C. Faustman, and C. J. Lopez-Bote, editors, Antioxidants
in Muscle Foods. Wiley-Interscience, New York. p. 113 133.
Rogers, H. B., J. C. Brooks, J. N. Martin, A. Tittor, M. F. Miller, and M.
M. Brashears. 2014. The impact of packaging system and temper-
ature abuse on the shelf life characteristics of ground beef. Meat
Sci. 97(1):110. doi:10.1016/j.meatsci.2013.11.020
Sammel, L. M., M. C. Hunt, D. H. Kropf, K. A. Hachmeister, and D. E.
Johnson. 2002. Comparison of assays for metmyoglobin reduc-
ing ability in beef inside and outside semimembranosus muscle. J.
Food Sci. 67:978984. doi:10.1111/j.1365-2621.2002.tb09439.x
Seyfert, M., R. A. Mancini, M. C. Hunt, J. Tang, C. Faustman, and
M. Garcia. 2006. Color stability, reducing activity, and cy-
tochrome c oxidase activity of ve bovine muscles. J. Agric.
Food Chem. 54:89198925. doi:10.1021/jf061657s
Steele, K. S., M. J. Webber, E. A. E. Boyle, M. C. Hunt, A. S. Lobaton-
Sulabo, C. Cundith, Y. H. Hiebert, K. A. Abrolat, J. M. Attey, S.
D. Clark, D. E. Johnson, and T. L. Roenbaugh. 2016. Shelf life
of fresh meat products under LED or uorescent lighting. Meat
Sci. 117:7584. doi:10.1016/j.meatsci.2016.02.032
Suman, S. P., and P. Joseph. 2013. Myoglobin chemistry and meat
color. Annu. Rev. Food Sci. Technol. 4:7999. doi:10.1146/
annurev-food-030212-182623
Suman, S. P., M. C. Hunt, M. N. Nair, and G. Rentfrow. 2014.
Improving beef color stability: Practical strategies and un-
derlying mechanisms. Meat Sci. 98:490–504. doi:10.1016/j.
meatsci.2014.06.032
Tarladgis, B. G., B. M. Watts, N. T. Younathan, and L. Dugan.
1960. A distillation method for the quantitative determina-
tion of malonaldehyde in rancid foods. Am. Oil Chem. Soc.
37:4448. doi:10.1007/BF02630824
Trinderup, C. H., and Y. H. B. Kim. 2015. Fresh meat color evaluation
using a structured light imaging system. Food Res. Int. 71:100
107. doi:10.1016/j.foodres.2015.02.013
United States Department of Agriculture (USDA). 2014. Institutional
meat purchase specications. https://www.ams.usda.gov/sites/
default/les/media/IMPS_100_Fresh_Beef%5B1%5D.pdf. (ac-
cessed 15 January 2017).
United States Department of Energy (US DOE). 2016. Energy savings
forecast of solid-state lighting in general illumination applications.
https://energy.gov/sites/prod/files/2016/10/f33/energysavings-
forecast16_0.pdf (accessed 15 January 2017).
Von Seggern, D. D., C. R. Calkins, D. D. Johnson, J. E. Brickler,
and B. L. Gwartney. 2005. Muscle proling: Characterizing
the muscles of the beef chuck and round. Meat Sci. 71:39-51.
doi:1016/j.meatsci.2005.04.010
Wu, W., X. G. Gao, Y. Dai, Y. Fu, X. M. Li, and R. T. Dai. 2015. Post-
mortem changes in sarcoplasmic proteome and its relationship
to meat color traits in m. semitendinosus of Chinese luxi yellow
cattle. Food Res. 72:98–105. doi:10.1016/j.foodres.2015.03.030
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... In addition, Reynolds et al. [49] documented that ground beef samples formulated with 5% fat demonstrated a greater a* value than the 25% fat counterpart samples after 7 days of retail display. The different light sources utilized by Reynolds et al. [49], which could influence meat color stability and lipid oxidative stability [48,[50][51][52], might have contributed to the observed variation in the a* value. ...
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... The observed trend that SMB and extracts performed better than CTR in terms of a*, b*, and C* values could be due to reduced conversion of oxymyoglobin to metmyoglobin by the antioxidant effects of sulphites and bioactive phytochemicals (Bouarab-Chibane et al., 2017;D'Amore et al., 2020;Faustman & Suman, 2017). The L* and a* values observed in the present study were within the threshold values of ≤46.3 and ≥14.5, respectively, which are deemed acceptable thresholds by consumers of fresh beef patties (Cooper, Suman, Wiegand, Schumacher, & Lorenzen, 2018;Holman, van de Ven, Mao, Coombs, & Hopkins, 2017). Lower H* values observed for beef patties treated with either commercial preservative (SMB) or citrus and winery by-product extracts compared to CTR could also be attributed to the protective effects of sulphites, flavonoids, ascorbic acid and limonoids (Bouarab-Chibane et al., 2017;Luciano et al., 2011). ...
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... As was expected, the three films tested exhibited a high absorbance at 200 and 280 nm, mainly due to the absorption of light by carbonyl groups within the peptide bonds, the presence of aromatic amino acids that form part of the primary structure of the proteins, and disulphide bonds (Banga, 2015). This property is common to any protein-based film, and it is very desirable for packaging applications, since it can act as a barrier to UV radiation, hindering the UV-mediated oxidative degradation of the lipids that can occur in many food items (Cooper, Suman, Wiegand, Schumacher, & Lorenzen, 2018). When analysing the absorbance in the visible range, this was significantly higher for the control films in the entire range. ...
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... Therefore, it is important to determine the antioxidant activity of the product. The color of the meat depends on the concentration of the pigment (MYG and hemoglobin), oxidation-reduction status, and light-scattering properties of the meat [39][40][41]. In this study, we recorded color measurements of the meat product to better interpret the role of antioxidative molecules from fermented beef. ...
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