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J Sci Food Agric 1998, 78, 522È526
The Eþect of Storage Temperature on Drip Loss
from Fresh Beef
Marjan J A den Hertog-Meischke,*1 Frans J M Smulderst
and Jan G van Logtestijn
Department of the Science of Food of Animal Origin, Faculty of Veterinary Medicine, Utrecht University,
PO Box 80.175, 3508 TD Utrecht, The Netherlands
(Received 28 January 1997 ; revised version received 23 February 1998 ; accepted 6 April 1998)
Abstract : The e†ect of post rigor storage temperature on drip loss of two bovine
muscles (M longissimus thoracis and M semimembranosus) was examined using
12 Dutch Friesian Holstein bulls. Drip loss of both longissimus and semimembranosus muscles was inÑuenced by post rigor storage temperature. Higher
storage temperatures resulted in increased drip losses, probably caused by a
decrease in viscosity of the drip. The increase was most marked for the M
longissimus thoracis. The relationship between drip loss and storage temperature
was not linear ; drip loss was found to be less a†ected by storage temperature as
the latter was increased. The observed relationship could not be explained by a
decrease in viscosity of the drip at higher temperatures alone. It was thought that
faster ageing of the meat at elevated temperatures might increase the myoÐbrillar
water-holding capacity, resulting in a decreased drip loss. However, this hypothesis requires further research. ( 1998 Society of Chemical Industry.
J Sci Food Agric 78, 522È526 (1998)
Key words : beef ; storage temperature ; water-holding capacity ; meat quality
INTRODUCTION
storage variables, such as method of suspension, cutting,
packaging and storage temperature (O†er and Knight
1988). The e†ect of temperature on drip loss was studied
by OÏKee†e and Hood (1980È1981). They reported that
increasing storage temperature from 0 to 10¡C results in
an appreciable rise in the amount of drip lost from beef
steaks. The relationship between storage temperature
and drip loss was not linear. Drip loss increased more
rapidly in the temperature range from 5 to 10¡C than it
did from 0 to 5¡C ; this e†ect was most pronounced in
bovine M psoas major as compared to M gluteus medius
and M semimembranosus.
The cause of the temperature e†ect on drip loss is
unknown. O†er and Knight (1988) suggested that the
lowered viscosity of the water at higher temperatures
might be responsible for the elevated drip losses.
However, no evidence for this suggestion could be
found in the literature. Therefore, the objective of the
present experiments was to characterise the relationship
between storage temperature and drip loss of bovine M
longissimus thoracis and M semimembranosus and to
study the possible mechanisms involved. To this end,
The ability of fresh meat to hold on to its own water
(water-holding capacity) is an important quality aspect,
since it a†ects consumer acceptance and Ðnal weight of
the product. Water can be lost from meat by evaporation, in the form of drip and Ðnally in the course of
cooking. Drip loss is thought to result from lateral
shrinkage of myoÐbrils post mortem, causing water to be
expelled into the muscleÏs extracellular space (O†er and
Knight 1988). After death, large gaps appear between
both Ðbre bundles and individual Ðbres, which function
as longitudinal channels with outlets at the cut surface
of the meat. The Ñuid in these channels may be transported to the surroundings by the action of gravity and
hence is the main source of drip (O†er et al 1989).
Drip loss from fresh meat is inÑuenced by many
* To whom correspondence should be addressed.
” Present address : Institute of Meat Hygiene, Meat Technology and Food Science, Veterinary Medical University of
Vienna, Josef Baumanngasse 1, A-1210 Vienna, Austria.
522
( 1998 Society of Chemical Industry. J Sci Food Agric 0022È5142/98/$17.50.
Printed in Great Britain
E†ect of storage temperature on drip loss of beef
beef steaks were stored at a range of temperatures,
covering that found in commercial practice. The viscosity and protein concentration of drip as related to
storage temperature was assessed.
523
Protein concentration of drip
Protein concentration of drip was measured using the
biuret method of Gornall et al (1949), with bovine
serum albumin as a standard.
MATERIALS AND METHODS
Viscosity of drip
Experimental
Twelve Dutch Friesian Holstein bulls (age 2 years ;
carcass weight 400È460 kg) were slaughtered under
commercial circumstances. To facilitate skinning, an
electrical current was used (250 V, 50 Hz, 2 s). No electrical stimulation was applied. After ^48 h chilling
(2¡C, air velocity 0É5 m s~1), M longissimus thoracis
(LT) and M semimembranosus (SM) from the left side of
the carcass were excised. From each muscle, 5 portions
of 100 g were randomly subjected to one of the following storage temperatures : 1, 3, 5, 7É5 or 10¡C. After 3
days storage, amount of drip and its protein concentration were determined. The viscosity of one drip sample
was measured at di†erent temperatures.
In a second experiment one Dutch Friesian cow (age
7 years ; carcass weight 258 kg) was slaughtered under
the above mentioned conditions. From the M longissimus thoracis, 5 steaks of approximately 200 g were cut,
which were subsequently stored in plastic trays at temperatures of 1, 3, 5, 7É5 or 10¡C. After 3 days storage,
pH, drip loss, myoÐbrillar protein degradation and
myoÐbrillar water-holding capacity were assessed.
Muscle pH and temperature
Muscle pH was measured at 45 min, and 3, 24 and 48 h
post mortem and after 3 days storage using a portable
pH meter (type CG818, Scott GeraŽte, Hofheim,
Germany), equipped with a combined (glass/reference)
electrode (type N48A, Schott GeraŽte, Hofheim,
Germany). Temperature was monitored at the same
time with a digital thermometer (Tastotherm D700,
Germany).
Drip loss
In experiment 1, drip loss was determined in slices of
muscle ^100 g, which were suspended from Ðsh-hooks
in plastic pouches at temperatures of 1, 3, 5, 7É5 or
10¡C. After 3 days storage, weight loss was assessed
(Honikel 1987) and drip was collected to determine its
protein content. A temperature data logger was used to
monitor changes in the applied temperature. During
storage, only small variations in temperature (^0É3¡C)
occured. In the second experiment on lab scale, drip
loss was determined by weighing the steaks before and
after storage. In both experiments, drip loss was
expressed as (%) of the initial weight of the sample.
Viscosity of drip was assessed with a BrookÐeld LVF
viscosity meter in conjunction with a UL-adapter. Viscosity was measured at 30 rpm and expressed in cPoise.
MyoÐbrillar protein degradation
MyoÐbrils were extracted according to the method of
Ouali and Talmant (1990). Degradation of myoÐbrillar
proteins was assessed with horizontal SDS-PAGE electrophoresis on a 80È180 g litre~1 precast ExcelGel'
SDS (Pharmacia Biotech). Samples with 4 mg ml~1
myoÐbrillar protein were diluted to 2 mg ml~1 myoÐbrillar protein with sample bu†er containing 8 M Urea,
2 M thiourea, 0É025 M Tris (pH 6É8), 0É075 M DTT and
0É104 M SDS. Samples were heated at 100¡C for 5 min
and then loaded on gel (10 ll). Gels were stained overnight in Coomassie R 350 (1 g litre~1) in glacial acetic
acid/water/ethanol, 1 : 5 : 5 (v/v/v) and destained over
several days by repeated washes in solutions containing
100 ml litre~1 glacial acetic acid and 250 ml litre~1
ethanol. The intensity of the protein bands was measured with a LKB Ultrascan XL Enhanced Laser Densitometer. Intensity of troponin T and 30 kDa bands
was expressed as % relative to actin.
MyoÐbrillar water-holding capacity
Determination of the myoÐbrillar water-holding capacity was based on the method of Penny et al (1963).
Eight grams of muscle were homogenised in 80 ml icecold 0É1 M KCl. The homogenate was kept on ice for
30 min. After washing several times with 0É1 M KCl, a
suspension of 6 mg protein ml~1 was made. pH of the
suspension was measured with a Radiometer PHM83
Autocal pH meter equipped with a combined (Glass/
reference) electrode (type GK2401C, Radiometer,
Denmark). After centrifugation at 1200 ] g for 5 min,
the supernatant was discarded and the precipitate
weighed. MyoÐbrillar water-holding capacity was
expressed as g H 0 g protein~1.
2
Statistical analysis
SigniÐcance of di†erences was tested using the ANOVA
procedure. Fixed factors in the analysis were temperature of storage and muscle. Means were separated
with TukeyÏs method.
M J A den Hertog-Meischke, F J M Smulders, J G van L ogtestijn
524
RESULTS AND DISCUSSION
The results of the pH and temperature measurements
are presented in Table 1. The results of the temperature
measurements indicate a slower chilling rate of the SM
muscle as compared to the LT muscle. Also, chilling
rate within the SM muscles varied, as can be seen from
the high standard deviation at 24 h post mortem. The
use of electrical current to facilitate skinning resulted in
an accelerated glycolysis. The pH values observed at 3 h
post mortem, were similar to those often found in electrically stimulated carcasses (for review see Seideman and
Cross 1982). SM muscles had a signiÐcantly higher rate
of pH decline as compared to the LT muscles. As the
rate of glycolysis is temperature dependent (Greaser
1986), the faster pH fall of SM muscles may be associated with the slower chilling rate of this muscle. Ultimate pH was reached within 24 h post mortem,
regardless the muscle considered. Di†erences in ultimate
pH between LT and SM muscles were found to be negligible.
A graphic presentation of the e†ect of storage temperature on drip loss is given in Fig 1. In every temperature treatment group, higher drip loss values were
recorded for SM muscles than for LT muscles. This
Ðnding was expected as drip loss is increasing with
increasing rate of pH fall and decreasing chilling rate
(Penny 1977 ; O†er 1991). However, di†erences in
muscle Ðbre type, muscle Ðbre size and amount of collagen between LT and SM muscles may also play a role
in determining the di†erence in drip loss between the
two muscles. In both LT and SM muscles, drip loss
increased with increasing storage temperature. The
observed e†ect was more pronounced in LT than in SM
muscles, which may be caused by di†erences in muscle
structure between the two muscles. The relationship
between storage temperature and drip loss was not
linear ; drip loss was found to be less a†ected by storage
temperature as the latter was increased (Fig 1). These
results are in contrast with the observations of OÏKee†e
Fig 1. E†ect of storage temperature on drip loss of M longissimus thoracis (LT) and M semimembranosus (SM) after 3 days
of storage (mean ^ SD).
and Hood (1980È1981), who reported that drip loss
increased more rapidly with temperature between 5¡C
and 10¡C than between 0¡C and 5¡C. It is not clear
were this discrepancy results from. Probably, the
method of measuring drip loss plays a role. OÏKee†e
and Hood (1980È1981) measured drip loss of vacuum
packed meat after 4 days of storage. In their experiment,
the meat was already aged for 4 days before sampling.
However, more research is needed to establish the
relationship between storage temperature and drip loss.
Protein concentration of drip from SM samples was
lower
than
that
from
the
LT
samples
(58É9 ^ 6É9 mg ml~1
for
SM
muscles
versus
66É7 ^ 7É7 mg ml~1 for LT muscles ; P \ 0É05). Savage
et al (1990) have shown that protein content of drip
decreases with increasing amount of drip. They suggested that this may be the result of sarcoplasmic
protein precipitation onto the myoÐbrils. This may also
explain the observed di†erence in protein concentration
between SM and LT samples in the present experiment.
Although protein concentration varied between individual samples, di†erences between temperature treatment
groups were negligible, indicating that the protein con-
TABLE 1
pH and temperature (mean ^ SD) of M longissimus thoracis (LT) and M semimembranosus (SM) at various times post mortema,b
T ime post mortem
45
3
24
48
min
h
h
h
pH
Temperature (¡C)
LT
SM
LT
SM
6É78 ^ 0É12
5É99 ^ 0É17a
5É50 ^ 0É04
5É49 ^ 0É03
6É72 ^ 0É07
5É77 ^ 0É06b
5É50 ^ 0É03
5É50 ^ 0É03
38É7 ^ 0É4
30É6 ^ 0É9a
2É0 ^ 0É3a
2É1 ^ 0É1
39É1 ^ 0É5
32É0 ^ 0É9b
8É7 ^ 1É1b
2É2 ^ 0É4
a Experiment 1, n \ 12 per group.
b Within traits, within muscles, means lacking a common following letter di†er signiÐcantly (P \ 0É05).
E†ect of storage temperature on drip loss of beef
525
centration of drip was not inÑuenced by storage temperature. Penny (1975) studied the e†ect of freezing and
centrifuging on the amount of drip and its protein concentration. Both these treatments resulted in a decrease
in the protein concentration and an increase of the
amount in drip. Penny (1975) postulated that through
freezing or centrifuging additional water was removed
from those compartments within the meat structure (ie
the spaces between the myoÐlaments and those in the
tubulus of the sarcoplasmic reticulum) which contain a
low amount of soluble proteins. Since in the present
experiment no signiÐcant di†erences in protein concentration between temperature treatment groups was
recorded, it is suggested that the increase in drip loss
with increasing storage temperature is not due to
removal of additional water from the spaces within the
myoÐlaments or sarcoplasmic reticulum.
O†er and Knight (1988) suggested that storage temperature a†ects drip loss via an e†ect on the viscosity of
the drip. At higher temperatures, viscosity will be lower
resulting in a higher rate of migration of drip through
the channels in and between the muscle Ðbres. In Fig 2
the relationship between viscosity of drip and temperature is shown. For comparison, the relationship
between temperature and viscosity of water has been
included. As di†erences in protein concentration at
various temperatures were negligible, this relationship is
only presented for drip with a protein content of
81É6 mg ml~1, the highest value found in the present
experiment. At lower protein concentrations this
relationship will follow a similar course, intermediate
between this curve and the one for water. From Fig 2 it
can be seen that between viscosity and temperature an
exponential relationship existed, which can be described
by the following equation :
g \ 4É65 e~0Õ02T
(1)
where g is the viscosity (cP) and T is the temperature
(¡C).
In samples with transversal cut surfaces and longitudinal Ðbre axis (as in the present experiment), the rate at
Fig 2. Relationship between temperature and viscosity of drip
in a sample with a protein concentration of 81.6 mg ml~1 and
between temperature and the viscosity of water.
which Ñuid would Ñow from the meat channels can be
described with the model given by O†er and Knight
(1988) :
t
1@2
\
9gy2
2px2
(2)
where t is the time in which half the Ñuid is squeezed
1@2
out ; g is the viscosity of the Ñuid ; y is the length of the
channels ; p is the pressure exerted on the channels by
the sample weight ; and x is the initial diameter of the
meat channel.
From eqn (2) it follows that the time in which half of
the Ñuid in the meat channels is squeezed out (t )
1@2
declines with the decrease in viscosity and thus, with an
increase in storage temperature. However, upon replacing g by eqn (1), it becomes apparent that, according to
the model of O†er and Knight (1988), drip loss should
increase more rapidly at higher storage temperatures. In
the present experiment, this would mean that the
increase in drip loss should be smaller between 1 and
3¡C than between 7É5 and 10¡C. However, this was not
the case. Hence, although increased drip loss at higher
storage temperatures was indeed associated with
decreased viscosity of the drip, this failed to explain the
relationship between drip loss and temperature
observed in our study.
Another possible explanation for the non-linear
relationship between storage temperature and drip loss
may be based on the e†ect of ageing on water-holding
capacity. Ageing during storage results in an increase of
water-holding capacity, possibly as a consequence of
disintegration of myoÐbrillar proteins by proteolytic
enzymes (Hamm 1986 ; Paterson et al 1988 ; Boles et al
1992). Since enzymatic reactions proceed at faster rates
as temperature increases, it was expected that ageing
e†ects and thus improvement of water-holding capacity
would occur more rapidly at higher storage temperatures. The total drip loss after storage at higher
temperatures would then be determined by on the one
hand the higher rate of drip formation (due to lowered
viscosity) and the smaller amount of drip (due to
improved water-holding capacity) on the other. To test
this hypothesis, a small experiment on lab scale was
conducted, in which degradation of myoÐbrillar proteins and myoÐbrillar water-holding capacity were
studied as a function of storage temperature.
The results of the drip loss measurements showed the
same pattern as was found in Fig 1 : increasing storage
temperatures resulted in elevated drip losses, but drip
loss became less dependent on temperature as the latter
was increased (data not shown).
MyoÐbrillar water-holding capacity increased also
with increasing storage temperature. In contrast to drip
loss, myoÐbrillar water-holding capacity increased more
rapidly with increasing storage temperature in the range
from 5 to 10¡C than it did in the range from 1 to 5¡C
526
M J A den Hertog-Meischke, F J M Smulders, J G van L ogtestijn
(Fig 3). The increase in myoÐbrillar water-holding
capacity was not due to an increase in pH of the meat :
the pH after storage did not di†er between temperature
groups.
Degradation of myoÐbrillar proteins during ageing is
often characterised by SDS-gel electrophoresis. Bands
with molecular weights of 27È30 kDa gradually appear
and the Troponin T band disappears. SDSelectrophoresis of samples stored at 1, 3 and 5¡C
showed little protein degradation, as the 30 kDa band
was not measurable. Intensity of the Troponin T band
did not di†er between samples stored at 1, 3, and 5¡C
(intensity expressed as % relative to actin \13É0).
However, in gels from samples stored at 7 and 10¡C, the
30 kDa band appeared (intensity expressed as % relative to actin 7É3 and 11É1, respectively), coinciding with
disappearance of the Troponin T band (intensity
expressed as % relative to actin 8É3 in both cases). This
illustrates that higher storage temperatures lead to
faster ageing of meat. The fact that an increase in
storage temperature results in both faster ageing and
increase in myoÐbrillar water-holding capacity suggests
that the lower amount of drip at higher temperatures is
due to the faster ageing. This hypothesis deserves
further investigation.
In summary, the results showed that an increase in
the storage temperature of beef causes an increase in the
amount of drip, probably as a result of the decrease in
viscosity of the Ñuid within the meat. The observed
relationship between storage temperature and drip loss
is not linear and cannot be explained by a decline in
viscosity alone. The increase in amount of drip is lower
with increasing storage temperatures. This may be
related to increased proteolysis at higher storage temperatures, causing a faster improvement of waterholding capacity. The e†ect of storage temperature on
the total drip at a Ðxed storage time may therefore be
determined by the e†ect of drip viscosity and the coinciding improvement of water-holding capacity induced
by ageing at higher temperatures.
Fig 3. E†ect of storage temperature on the myoÐbrillar waterholding capacity (M-WHC) of beef loin steaks after 3 days of
storage.
ACKNOWLEDGEMENTS
The authors gratefully acknowledge The NetherlandsÏ
Product Boards for Livestock, Meat and Eggs at Rijswijk and Edah Supermarkten B.V. at Helmond for supporting this study. Thanks are also due to A van Dijk,
G Keizer and P Schippers for technical assistance.
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