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Synergistic effect of low concentration electrolyzed water and calcium lactate to ensure microbial safety, shelf life and sensory quality of fresh pork


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The objectives of this study were to evaluate the effectiveness of low concentration electrolyzed water (LcEW) and other carcass decontaminants against Escherichia coli O157:H7 and Listeria monocytogenes in fresh pork and to conduct the shelf life/sensory study of pork. Pork samples were inoculated with approximately 5 log cfu/g of afore mentioned pathogens and dip treated with distilled water (DW), aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium hypochlorite solution (NaOCl), LcEW, strong acidic electrolyzed water (SAEW), and LcEW + CaL for 5 min at room temperature (23 ± 2 °C). The greatest reduction (3.0–3.2 log cfu/g) was achieved with LcEW + CaL against pathogens and significantly differed (p < 0.05) from other treatments. This combination also extended shelf life of pork up to 6 days at 4 °C storage.
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Synergistic effect of low concentration electrolyzed water and calcium lactate to
ensure microbial safety, shelf life and sensory quality of fresh pork
S.M.E. Rahman
, Jun Wang
, Deog-Hwan Oh
Department of Food Science and Biotechnology and Institute of Bioscience and Biotechnology, Kangwon National University, 192-1 Hyoja 2 dong, Chuncheon, Gangwon 200-701,
Republic of Korea
Department of Animal Science, Bangladesh Agricultural University, Mymensingh 2202, Bangladesh
article info
Article history:
Received 15 December 2011
Received in revised form
18 June 2012
Accepted 23 June 2012
Combination of LcEW þCaL
Microbial safety
Shelf life
Sensory quality
Pork meat
The objectives of this study were to evaluate the effectiveness of low concentration electrolyzed water
(LcEW) and other carcass decontaminants against Escherichia coli O157:H7 and Listeria monocytogenes in
fresh pork and to conduct the shelf life/sensory study of pork. Pork samples were inoculated with
approximately 5 log cfu/g of afore mentioned pathogens and dip treated with distilled water (DW),
aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium hypochlorite solution (NaOCl),
LcEW, strong acidic electrolyzed water (SAEW), and LcEW þCaL for 5 min at room temperature
(23 2
C). The greatest reduction (3.0e3.2 log cfu/g) was achieved with LcEW þCaL against pathogens
and signicantly differed (p<0.05) from other treatments. This combination also extended shelf life of
pork up to 6 days at 4
C storage.
Ó2012 Elsevier Ltd. All rights reserved.
1. Introduction
About 40 percent of all meat consumed in the world is pork,
followed by poultry meat at 30 percent, and beef at 25 percent
(FAO, 2006). Although the consumption of pork products is
increasing, the microbial safety of pork during storage and
marketing remains a concern. Meat products are highly perishable,
and food poisoning can occur as a result of careless processing and
storage (Aymerich, Picouet, & Monfort, 2008). The main ora
responsible for spoilage in fresh meat products during aerobic
storage is the Pseudomonas species and they are dominant in
poultry meat, pork and beef and lamb (Coates, Beattie, Morgan, &
Widders, 1995). Microbial contamination in meat is an important
factor associated with meat quality. It has been found that bacterial
contamination, such as Salmonella Typhimurium, Escherichia coli
O157:H7 and Listeria monocytogenes, impacted meat safety (Cutter,
2000;Dorsa, Cutter, & Siragusa, 1998;Nissen, Alvseike, Bredholt,
Holck, & Nesbakken, 2000). Therefore, to improve the microbial
safety of pork during processing and storage, various processing
techniques have been used for reduction of bacterial contaminants
to extend shelf life (Latha, Sherikar, Waskar, Dubal, & Ahmed, 2009;
Schirmer & Langsrud, 2010;Viana, Gomide, & Vanetti, 2005).
Constant efforts have been made to create effective and new
technologies for the decontamination of carcasses and meat
products (Huffman, 2002;Zhou, Xu, & Liu, 2010). Several inter-
vention strategies have been developed to reduce the level of
bacteria on pork or other animal carcass surfaces such as washing
and sanitizing with hot or chilled water (Frederick, Miller,
Thompson, & Ramsey, 1994;Özdemir et al., 2006), chlorinated
and electrolyzed water (Ding, Rahman, Purev, & Oh, 2010;Fabrizio
& Cutter, 2004;Park, Hung, & Brackett, 2002), food grade acids
(Dubal et al., 2004;Pipek et al., 2006), salts (Jensen et al., 2003;
Latha et al., 2009), ozone (Jaksch et al., 2004), chlorine dioxide
(Pohlman, Stivarius, McElyea, Johnson, & Johnson, 2002), essential
oil and nisin (Solomakos, Govaris, Koidis, & Botsoglou, 2008). All
these sanitizers act differently on different types of organisms, but
the information is limited on the action of these sanitizers on
articially inoculated specic organisms in meat. Moreover, most of
these sanitizers are made from the dilution of condensed solutions,
which in handling involves some risk and is troublesome. A sani-
tizer named low concentration electrolyzed water (LcEW) that is
not produced from the dilution of a hazardous condensed solution
has been reported in several previous researches as a safe and
promising sanitizer (Ding, Rahman, & Oh, 2011;Rahman, Ding, &
Oh, 2010a,2010b). Thus, LcEW is being used in this study as an
alternative non-thermal sanitizer, and furthermore, it has been
*Corresponding author. Tel.: þ82 33 250 6457; fax: þ82 33 241 0508.
E-mail addresses: (S.M.E. Rahman), wangjun@ (J. Wang), (D.-H. Oh).
S.M.E. Rahman and Jun Wang share the co-rst-authorship.
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Food Control 30 (2013) 176e183
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reported from our previous research that LcEW treatment could
also help to maintain the physicochemical and sensory quality of
fresh chicken breast meat (Rahman, Park, Song, Al-Harbi, & Oh,
2012). Combinations of LcEW and other measures are also possible.
Organic acid salts such as calcium lactate have been used in the
meat industry because of their ability to increase avor, prolong
shelf life, and improve the microbiological safety of products
(Lawrence, Dikeman, Hunt, Kastner, & Johnson, 2003;Naveena,
Sen, Muthukumar, Vaithiyanathan, & Babji, 2006;Selgas, Salazar,
& García, 2009). Meat and meat products are considered to be
a relatively minor source of calcium (Fennema, 1996), so CaL
dipping is useful for enriching these meat products with calcium. In
addition, CaL helps to maintain tenderness and palatability of meat
products (Lawrence et al., 2003). Therefore, we combined
LcEW þCaL and applied in our study to nd any synergistic or
hurdle effect. Accordingly, the present work was undertaken to
study and compare the antimicrobial effect of LcEW alone and its
combination with CaL as a safe and natural sanitizer in handling or
food application comparison with other commercial sanitizers
against background ora and inoculated pathogens associated with
fresh pork. Sensory quality and shelf life of pork at refrigeration
temperature (4
C) was also studied.
2. Materials and methods
2.1. Bacterial cultures
The three strains each of E. coli O157:H7 (B0259, B0297 and
B0299) and L. monocytogenes (ATCC 19115, ATCC 19111 and Scott A)
used in this experiment were obtained from Department of Food
Science, University of Georgia (Grifn, GA, USA), and Health
Research Department (Gyeonggi-do, Republic of Korea), respec-
tively. Stock cultures of each pathogen were transferred into tryptic
soy broth (TSB; Difco, NJ, USA) and incubated for 24 h at 35
Following incubation, 10 mL of each culture was sedimented by
centrifugation (4000g for 10 min at 4
C), washed and resus-
pended in 10 mL of 0.1% peptone water (pH 7.1) to obtain a nal cell
concentration of 10
cfu/mL. Subsequently, resulting suspensions of
each strain of the 2 pathogens were combined to construct culture
cocktails. These culture cocktails were used in the following
experiments. The bacterial population in each cocktail culture was
conrmed by plating 0.1 mL portions of appropriately diluted
culture on tryptic soy agar (TSA) plates and incubating the plates at
C for 24 h.
2.2. Sample preparation
Boneless pork loins (48 h post-slaughter) were obtained from
a retail store in Chuncheon, Korea. External fats and fascia were
removed and then stored in a refrigerator at 4
C prior to use for the
experiment within 3 h. Pork samples were cut into pieces of similar
size (2.5 2.5 cm) using a sterile knife. Before inoculation, each
sample weighed 10 0.2 g.
2.3. Inoculation
To destroy the background microora, pork samples were
surface treated using UV light in a biological safety hood. Surfaces
were evenly exposed to UV light by turning sections every 10 min
for a total time of no more than 30 min (Cutter & Siragusa, 1994).
After applying this treatment, the naturally existing bacterial
population was reduced to an undetectable level (with 10 cfu/g
detection limit). Accordingly, mixed inocula (0.1 mL, more than
cfu/mL) of E. coli O157:H7 and L. monocytogenes were spread
separately on the top and bottom surface of each piece of fresh pork
using a sterile glass rod to obtain an inoculated level of 10
log cfu/g
(Zhang, Kong, Xiong, & Sun, 2009). Then the samples were kept in
a laminar ow hood for 20e30 min at room temperature
(23 2
C) to allow for bacterial attachment. Inoculated samples
without LcEW, SAEW, and LcEW þCaL treatments were used as
2.4. Preparation of treatment solutions
Low concentration electrolyzed water (LcEW), with a pH of
6.8,oxidation reduction potential (ORP) of 700e720 mV and avail-
able chlorine concentration (ACC) of 10 mg/L used in this study was
produced by electrolysis of a dilute NaCl solution (0.9%) in
a chamber without a membrane using an electrolysis device (model
D-7, Dolki Co. Ltd., Wonju, Korea) at a setting of 3 V and 1.47 A.
Strong acid electrolyzed water (SAEW) with a pH of 2.54, ORP of
110 0 e1120 mV was generated using electrolyzed water (EW)
generator (A2-1000, Korean E& S Fist Inc, Seoul, Korea) including
a small amount of salt solution (0.1%) and tap water at a setting of
12 A. with a residual chlorine concentration of about 50 mg/L. As
reported, SAEW was made by EW generator with a membrane to
separate the positive pole and negative pole, which had an acidic
pH, higher ORP value and always initially had a higher residual
chlorine concentration, compared to LcEW (Rahman et al., 2010a).
The sodium hypochlorite solution (NaOCl: pH 9.8, 100 mg/L avail-
able chlorine) was prepared with the addition of 0.1 g of NaOCl(DC
Chemical Co., Seoul, Korea) in 1 L of sterile DW. 3% (v/v) lactic acid
(pH 2.35) solutions were prepared with DW by using LA (90%,
Merck). 3% (w/v) calcium lactate (pH 6.5) solutions were prepared
with DW by using CaL (98%, Yakuri pure chemicals co. ltd., Kyoto,
Japan). Aqueous ozone (5 ppm) was produced on site by an elec-
trochemical process using a green water ozone generator
(GW-1000, Youl chon, Korea). Distilled water was used as control.
The pH, ORP and available chlorine concentration of treatment
solutions (LcEW and SAEW) were measured immediately before
treatment with a dual-scale pH meter (Accumet model 15, Fisher
Scientic Co., Fair Lawn, NJ) with pH and ORP electrodes. The
residual chlorine was determined by a colorimetric method using
a digital chlorine test kit (RC-3F, Kasahara Chemical Instruments
Corp., Saitama, Japan). The detection limit is 0e300 mg/L.
2.5. Dip wash treatments and microbiological analysis of meat
Inoculated and uninoculated pork samples (10 g) were placed in
sterile containers and immersed in treatment solutions (DW, AO,
3% LA, 3% CaL, NaOCl, LcEW, SAEW, and LcEW þCaL) at room
temperature (23 2
C). Unwashed meat samples were used as
control. To evaluate the effect of dipping time on the reduction of
microorganisms, each 10 g piece of uninoculated pork was dipped
for 0, 1, 3, 5, 7, and 10 min, respectively and nally 5 min dipping
was chosen for subsequent experiment. Following treatments, all
samples were aseptically excised and immediately placed in
a stomacher bag (Nasco Whirl-Pak, Janesville, WI, USA) containing
90 mL of BPW and homogenized for 2 min with a Seward stomacher
(400 Circulator, Seward, London, UK). After homogenization, 1 mL
aliquots of the sample were serially diluted in 9 mL of sterile
buffered peptone water and 0.1 mL of sample or diluents was
spread-plated onto each selective medium. Total bacterial counts
were determined by plating appropriately diluted samples onto
Tryptic Soy Agar (TSA). Yeasts and molds were plated on Potato
Dextrose Agar (PDA; Difco). Two selective media of Sorbitol Mac-
Conkey agar (SMAC; Difco) and Oxford Agar Base (OAB; Difco) were
used for the enumeration of E. coli O157:H7 and L. monocytogenes,
respectively. All plates were incubated at 37
C for 24 h, except for
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183 177
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yeasts and molds at 25
C for 3e5 d and expressed as log cfu/g. All
independent trials were replicated 3 times.
2.6. Shelf-life study
After treatment of uninoculated pork with LcEW, SAEW, and
LcEW þCaL; the samples were placed in polyethylene air-
permeable plastic bags (Robertson, 1993) and stored at 4
C for
12 days. Microbiological (Total Viable Count And Yeast and Mold)
analysis was carried out immediately after treatment and subse-
quently at storage intervals of 2, 4, 6, 8, 10, and 12 days. The end of
the shelf-life arrived when the population of a group of microor-
ganisms reached an unacceptable level of 6e7 log cfu/g (Zhou
et al., 2010) or when the sensory panel rejected the samples.
2.7. Evaluation of the sensory quality during the shelf-life
Sensory evaluation of pork was carried out to estimate the shelf-
life by a four member sensory panel using a six point standardized
scale for color and a four point standardized scale for odor (Latha
et al., 2009).
2.8. pH measurement
Values of pH were measured in triplicate in all meat samples
stored at 4
C by inserting the pH electrode (Model 720A, Orion/
Research, Boston, MA) directly into meat homogenates (1:10
2.9. Lipid oxidation
Lipid oxidation was assessed by the 2-thiobarbituric acid (TBA)
method of Witte, Krause, and Bailey (1970). TBARS values were
calculated from a standard curve of malonaldehyde and expressed
as mg malonaldehyde/kg meat.
2.10. Statistical analyses
All experiments were repeated three times, and the values
represent the means of duplicate determinations for each sample.
Data were expressed as the means standard deviation (SD). The
results were analyzed using the SPSS statistical package (SPSS Inc.,
Chicago, IL) and the signicance of difference was dened at
3. Results and discussion
The Physicochemical properties (pH, ORP, and ACC) of treatment
solutions (DW, AO, 3% LA, 3% CaL, NaOCl, LcEW, SAEW, and
LcEW þCaL) used in this study are presented in Table 1. The effect
of dipping times (1, 3, 5, 7, and 10 min) on the reduction of total
viable counts (TVC) on pork treated with DW, LcEW, and SAEW are
shown in Fig. 1. From these results, treatments exposed for 5 min
showed signicant difference (p<0.05) in reducing total bacteria
from the dipping times of 1 and 3 min, but there was no signicant
difference (p>0.05) from the dipping times of 7 and 10 min. Also 7
and 10 min dipping resulted in changing fresh color (visual esti-
mation) of pork. According to these results, 5 min dipping would be
the most appropriate to minimize the quality deterioration (color),
thus, it was chosen for the subsequent treatments which were done
at room temperature. In contrast, Park et al. (2002) and Fabrizio,
Sharma, Demirci, and Cutter (2002) examined the use of EO
water to inactivate Campylobacter jejuni or Salmonella spp. on
poultry. In these studies, it was determined that EO water was more
effective when the contact times were increased to >10 and 40 min,
respectively. Also, our previous report revealed that 10 min treat-
ment with LcEW at room temperature could signicantly reduce
the natural background microora and extend the shelf life of fresh
chicken breast meat (Rahman et al., 2012).
3.1. Decontamination of fresh pork
After sanitizing treatments in 5 min dipping, the populations of
TVC in the pork samples were 4.61, 4.31, 3.83, 3.67, 3.63, 3.57, 3.33,
3.21, and 2.41 log cfu/g for the control, DW, AO, 3% LA, 3% CaL,
NaOCl, LcEW, SAEW, and LcEW þCaL treatments, respectively
(Fig. 2). The greatest reduction was achieved with LcEW þCaL. This
combination treatment reduced the microbial load in the pork by
2.20 log cfu/g, compared to the unwashed control, whereas
washing with DW resulted in the lowest reduction by 0.30 log cfu/g.
Yeasts and molds had a more or less similar pattern to that of total
aerobic bacteria (Fig. 3). Initial populations of yeasts and molds in
the pork samples were 1.97, 1.76, 1.40, 1.25, 1.22, 1.13, 1.01, 0.90, and
0.40 log cfu/g for the control, DW, AO, 3% LA, 3% CaL, NaOCl, LcEW,
SAEW, and LcEW þCaL treatments, respectively. The LcEW þCaL
treatment caused the most effective reduction (p<0.05) of yeasts
and molds in the pork by 1.57 log cfu/g compared to the unwashed
control, whereas washing with DW only showed a reduction of
0.21 log cfu/g. These results demonstrate that combination of LcEW
with CaL is an effective sanitizer for microbial decontamination in
meat. Reduction in TVC by 0.98 log units was observed in the
present study for 3% CaL treated pork, which is in agreement with
the ndings of Latha et al. (2009),Mendonca, Molins, Kraft, and
Walker (1989) and Ahmed et al. (2003), whereas they used other
salt treatments. Latha et al. (2009) also observed TVC reduction by
about 2.32 log cfu/g on pork carcasses after hot water treatment
with slight to moderate changes in color while, we found
2.20 log cfu/g reduction of TVC in fresh pork treated by LcEW and
3% CaL combinedly without changing in color. Muhlisin et al. (2010)
reported that sodium acetate and calcium lactate lowered
(p<0.05) the aerobic and anaerobic bacterial counts in high oxygen
modied atmosphere packaging (OxyMAP) and nitrogen modied
atmosphere packaging (NitroMAP) which is in agreement with
Lawrence et al. (2003) who reported reduced antimicrobial plate
counts in beef longissimus dorsi owing to the effect of calcium salts.
The sodium and calcium salts of lactic acid are approved for use in
meat products as direct food ingredients (Anonymous, 1987)
Table 1
Physicochemical properties of treatment solutions.*
Treatment solutions pH ORP
(mV) ACC
7.0 0.1 412 18 0.3 0.1
6.6 0.1 1245 25 5.2 0.2 mg
/L of water
3% LA
2.35 0.2 613 10 ND
3% CaL
6.51 0.05 290 20 ND
10.6 0.2 630 15 100 4.5
6.8 0.2 700 10 10 0.1
2.54 0.3 1130 20 50 2.2
6.82 0.08 245 20 1.0 0.1
* Values are mean standard deviation, n¼3.
Oxidation reduction potential.
Available chlorine concentration.
Distilled water.
Aqueous ozone.
Lactic acid (3%).
Calcium lactate (3%).
Sodium hypochlorite solution.
Low concentration electrolyzed water.
Strong acidic electrolyzed water.
Low concentration electrolyzed water þ3% Calcium lactate.
Not detected.
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183178
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because they are derived from lactic acid, naturally present in the
animal tissues. Chen and Shelef (1992) found that CaL is equally
effective in controlling growth of aerobes and anaerobes in meats.
Pork samples were inoculated with approximately 5 log cfu/g of
L. monocytogenes and E. coli O157:H7 and treated with DW, AO, 3%
LA, 3% CaL, NaOCl, LcEW, SAEW, and LcEW þCaL. Sanitizing
treatment of the inoculated pork signicantly reduced the micro-
bial populations. After treatment, the initial populations of
L. monocytogenes in the pork samples were 5.07, 4.58, 3.99, 3.68,
3.60, 3.46, 3.25, 3.12, and 1.90 log cfu/g for the control, DW, AO, 3%
LA, 3% CaL, NaOCl, LcEW, SAEW, and LcEW þCaL treatments,
respectively (Fig. 4). In fact, the LcEW þCaL showed the greatest
reduction (p<0.05) of the population of L. monocytogenes by
3.17 log cfu/g compared to the unwashed control, whereas washing
with DW produced the lowest reduction by 0.49 log cfu/g. However,
E. coli O157:H7 had a similar pattern to L. monocytogenes. After
treatment, the populations of E. coli O157:H7 in pork samples were
5.03, 4.63, 4.02, 3.66, 3.59, 3.51, 3.30, 3.12,and 2.03 log cfu/g for the
control, DW, AO, 3% LA, 3% CaL, NaOCl, LcEW, SAEW, and
LcEW þCaL treatments, respectively (Fig. 5). LcEW þCaL signi-
cantly reduced (p<0.05) the populations of E. coli O157:H7 by
3.0 log cfu/g compared to the unwashed control, while washing
bbc bc bc cc
log cfu/g
Total viable count
Fig. 2. Surviving population of total viable count on fresh pork after washing with distilled water (DW), aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium
hypochlorite (NaOCl), low concentration electrolyzed water (LcEW), strong acidic electrolyzed water (SAEW), and LcEW þCaL relative to an unwashed control. Vertical bars
represent mean standard deviation (SD), n¼6. Bars labeled with different letters among treatments indicate a signicant difference (p<0.05).
aab b
bc ccc
bc ccc
Total viable count (log cfu/g)
Dipping time (min)
Fig. 1. Surviving population of total viable count on fresh pork after washing with distilled water (DW), low concentration electrolyzed water (LcEW) and strong acidic electrolyzed
water (SAEW) at different dipping times (min). Vertical bars represent mean standard deviation (SD), n¼6. Bars labeled with different letters in the same treatment indicate
a signicant difference (p<0.05).
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183 179
Author's personal copy
with DW reduced the populations by 0.40 log cfu/g. So many
research works have been published to date, examining the effects
of various intervention technologies to decontaminate fresh meat
and meat products. For instance, Latha et al. (2009) revealed that
the application of salts resulted in reduction of 2.88 and
3.29 log cfu/g for L. monocytogenes and E. coli respectively on pork
carcasses. On the other hand, effectiveness of EO water has been
reported against populations of E. coli,L. monocytogenes,C. coli,
C. jejuni, and S. Typhimurium associated with pork, chicken and
other meat surfaces which can result in reductions in those path-
ogens ranging from 0.48 to 3.0 log cfu/g (Fabrizio & Cutter, 2004,
2005;Fabrizio et al., 2002;Kim, Hung, & Russell, 2005;Park
et al., 2002). Recent studies have reported greater reductions
being achieved by combining interventions such as hot water and
organic acid washing (Castillo, Lucia, Mercado, & Acuff, 2001).
There is growing interest in the development of novel combina-
tions of natural antimicrobials and other food preservation systems
to improve the quality and safety of meat. Generally, bio-
preservation and natural antimicrobials provide an excellent
opportunity for such combined preservation systems. For example,
oregano essential oil, combined with MAP, were studied as hurdles
in the storage of fresh meat and a longer shelf life was observed
over that of the same packaging alone (Chouliara, Karatapanis,
Savvaidis, & Kontominas, 2007).
3.2. Shelf-life and sensory quality
The changes in microbial populations during the shelf-life study
are shown in Fig. 6. Combined treatment with LcEW and 3% CaL was
found to effectively control the growth of aerobic bacteria, yeast
and fungi during storage at 4
C for 12 days, when compared to
unwashed controls. All the untreated and treated pork samples
were stored at refrigeration temperature and shelf-life as well as
sensory scores of meat was assessed at intervals (Figs. 6e8). The
bbc bc bc cc
log cfu/g
Yeast and mold
Fig. 3. Surviving population of yeast and mold on fresh pork after washing with distilled water (DW), aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium
hypochlorite (NaOCl), low concentration electrolyzed water (LcEW), strong acidic electrolyzed water (SAEW), and LcEW þCaL relative to an unwashed control. Vertical bars
represent mean standard deviation (SD), n¼6. Bars labeled with different letters among treatments indicate a signicant difference (p<0.05).
ccd cd dde de
log cfu/g
L. monocytogenes
Fig. 4. Surviving population of L. monocytogenes on fresh pork after washing with distilled water (DW), aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium
hypochlorite (NaOCl), low concentration electrolyzed water (LcEW), strong acidic electrolyzed water (SAEW), and LcEW þCaL relative to an unwashed control. Vertical bars
represent mean standard deviation (SD), n¼6. Bars labeled with different letters among treatments indicate a signicant difference (p<0.05).
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183180
Author's personal copy
end of the shelf-life was considered to occur when the total aerobic
count was 7 log cfu/g and the total yeast count was 5 log cfu/g
(Alegria et al., 2010;Debevere, 1996, pp. 37e64; Gómez-López,
Devlieghere, Ragaert, & Debevere, 2007). The results of our study
revealed that onset of spoilage occurred after 12 days of storage for
treated (LcEW þCaL) pork with corresponding increases in the TVC
to 6.98 0.30 and YM to 5.2 0.28 log cfu/g, respectively. While, in
control samples spoilage was evidenced after 6 days of storagewith
corresponding increases in the TVC to 7.12 0.26 and YM to
5.18 0.25 log cfu/g, respectively. Thus, LcEW and CaL combination
treated pork meat samples could be stored for 12 days at refriger-
ation temperature, indicating that overall increase in shelf-life of 6
days in comparison with untreated pork meat samples. Whereas,
Latha et al. (2009) observed enhanced shelf-life of 7 days for pork
samples treated with salt combination compared to untreated
samples stored at 4
C. Similar ndings had been recorded by
Ahmed et al. (2003).Sawaya et al. (1995) also noted an increase in
shelf-life by 6e7 days at chill temperature (4
C) in broiler carcasses
bbc bc ccd cd
log cfu/g
E. coli
Fig. 5. Surviving population of E. coli O157:H7 on fresh pork after washing with distilled water (DW), aqueous ozone (AO), 3% lactic acid (LA), 3% calcium lactate (CaL), sodium
hypochlorite (NaOCl), low concentration electrolyzed water (LcEW), strong acidic electrolyzed water (SAEW), and LcEW þCaL relative to an unwashed control. Vertical bars
represent mean standard deviation (SD), n¼6. Bars labeled with different letters among treatments indicate a signicant difference (p<0.05).
Storage time (d)
Total viable count (log cfu/g)
LcEW + CaL
Storage time (d)
Yeast and mold (log cfu/g)
Fig. 6. Effects of various treatments on total viable count, and yeast and mold of pork
samples stored at refrigeration temperature. Values shown are mean standard
deviation (SD), n¼6. The error bars indicate 95% condence intervals.
Storage time (d)
Color scores
LcEW + CaL
Fig. 7. Color scores of treated and untreated pork samples. Six point scale for color:
1¼extremely bright red, 2 ¼moderately bright red, 3 ¼slightly bright red,
4¼slightly discolored, 5 ¼moderately discolored and 6 ¼extremely discolored.
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183 181
Author's personal copy
pretreated with lactic acid. Recent studies suggest that the use of
CaL may also enhance the shelf life of meat products during
refrigerated storage (Devatkal & Mendiratta, 2001).
Sensorial quality of the pork samples was evaluated bya sensory
panel throughout the storage period. The mean scores of sensory
attributes (color and odor) for untreated and treated pork are
shown in Figs. 7 and 8. Incipient spoilage changes in control, LcEW,
SAEW and LcEW þCaL treated samples with slight discoloration
and slight off odor were evident on days 4, 6 and 8 respectively.
However, marked spoilage with greenish discoloration and
noticeable off odor was seen on the 6th and the 12th day in control
and combination treated samples respectively. Sensory scores like
color (2.5 0.20) and odor (1.5 0.30) were within the acceptable
limit (Figs. 7 and 8). More or less similar shelf-life based on
sensorial properties has been described by others (Ahmed et al.,
2003;Dubal et al., 2004;Latha et al., 2009).
3.3. pH and TBARS value
The pH of the fresh untreated meat was 5.7 and it slowly
increased during storage (Fig. 9). This increase in pH during storage
could be due to degradation of proteins and production of amines
(Gill, 1983). Onset of spoilage was associated with pH rising in meat
during storage. Treatment of the fresh meat with LcEW þCaL
combination did not alter the pH much, and increases during
storage for 12 days were only 0.17 pH units. Incipient spoilage in the
control samples was manifest after 6 days of storage at 4
C with
corresponding increases in the pH to >6.0. Our results are also in
agreement with Tan and Shelef (2002).Holmer et al. (2009) cited
that higher pH and longer aging periods will result in increased
microbial proliferation and decreased shelf-life. Furthermore, as pH
increased, TVC increased, and these results are similar to those of
Rousset and Renerre (1991) that indicated bacterial counts were 10-
to 100-fold greater on high pH (¼6.20) meat than normal pH
(¼5.55) meat at various aging durations. Changes in Thiobarbituric
acid reactive substances (TBARS) values (mean S. D.) during
storage for 12 days at 4
C have shown in Fig.10. No or little changes
were observed in the refrigerated untreated meat before or at onset
of spoilage (6 days), but values increased on further storage. The
smallest changes during the 12-day storage were seen in
LcEW þCaL treatment, followed by LcEW treatment and the
highest increases in TBARS values were observed consistently
control samples. A similar trend was observed by Tan and Shelef
(2002). However, the acceptable limit of 1e2 mg malonaldehyde/
kg meat was revealed by Witte et al. (1970).
4. Conclusion
The slightly acidic low concentration electrolyzed water is novel
and no studies to that examine the effect of LcEW and its combi-
nation with calcium lactate to decontaminate fresh pork. The
decontamination of fresh pork by LcEW þCaL reduced the surface
microbial counts immediately after the treatment and retarded
microbial growth during storage. The results of the current study
are very promising, although carried out in laboratory condition.
Amongst the treatments, combination treatment showed highest
retardation of growth and multiplication of all inoculated patho-
gens, reduced the total viable counts as well as substantially
increasing the shelf-life of pork meat at refrigeration temperatures
compared with LcEW and SAEW treatment alone. Further works
need to be performed in a commercial slaughter plant to ascertain
the effects of LcEW þCaL. Also it can be elucidated by combining
LcEW with other organic acid salts i.e. sodium and potassium
lactate and applying in various meat and meat products with
different treatment method and time.
Storage time (d)
Odor scores
LcEW + CaL
Fig. 8. Odor scores of treated and untreated pork samples. Four point odor scale:
1¼no off odor, 2 ¼slightly off odor, 3 ¼moderately off odor and 4 ¼extremely off
e time
pH value
LcEW + CaL
Fig. 9. Changes in pH (mean SD) of treated and untreated pork samples during
storage at refrigeration temperature.
Storage time (d)
TBARS (mg MA/kg)
LcEW + CaL
Fig. 10. Changes in TBARS (mean S. D.) of treated and untreated pork samples during
storage at refrigeration temperature.
S.M.E. Rahman et al. / Food Control 30 (2013) 176e183182
Author's personal copy
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... As an alternative of the traditional chlorine sanitizer, the strong antibacterial effect of electrolyzed oxidizing water (EOW), which include strong acidic electrolyzed water (AEW) with pH of 2.2-2.7 approximately , slightly acidic electrolyzed water (SAEW) with pH of 5.0-6.5 approximately and neutral electrolyzed water pH of 7.0-8.0, showed a promising prospect in food industry (Huang, Hung, Hsu, Huang, & Hwang, 2008;Keskinen, Burke, & Annous, 2009;Rahman, Wang, & Oh, 2013). Apart from the disinfection efficacy on the planktonic strains, the removal effects of AEW on the bacterial biofilm were also demonstrated (Arevalos-Sánchez, et al., 2012;Cheng, et al., 2016;Okanda, et al., 2019). ...
... However, the current method to determine the chlorine compounds A c c e p t e d M a n u s c r i p t 8 concentration is iodometric method, which could not accurately determine the HClO contents. Considering that all the types of SAEW used in the present study have the similar pH values but different ACC (shown in Table 1), we confirm that ACC is the main factor affecting the disinfection efficacy of SAEW on L. monocytogenes, which is in agreement with the previous reports (Koide, et al., 2009;Rahman, et al., 2013). In addition, the results showed that the exposure time of L. monocytogenes on stainless steel surfaces on SAEW was another factor affected the disinfection efficacy. ...
... The strong bactericidal efficacy of SAEW has been recognized by many studies on lots of microorganisms including the pure stains and the attachment to food materials and food-contact surfaces (Koide, et al., 2009;Quan, Choi, Chung, & Shin, 2010;Rahman, et al., 2013;Wang, et al., 2014). Our present study also demonstrated the strong bactericidal efficacy of SAEW on the pure strains of L. monocytogenes on food-contact surfaces, which is consistent to the previous reports. ...
Full-text available
In the present study, the bactericidal efficacy of slightly acidic electrolyzed water (SAEW) against L. monocytogenes planktonic cells and biofilm on food-contact surfaces including stainless steel and glass was systematically evaluated. The results showed that SAEW (pH of 5.09 and available chlorine concentration (ACC) of 60.33 mg/L) could kill L. monocytogenes on food-contact surfaces completely in 30 s, whose disinfection efficacy is equal to that of NaClO solutions (pH of 9.23 and ACC of 253.53 mg/L). The results showed that long exposure time and high ACC contributed to the enhancement of the disinfection efficacy of SAEW on L. monocytogenes on food-contact surfaces. Moreover, the log reduction of SAEW treatment presented an increasing tendency within the prolonging of treatment time when SAEW was used to remove the L. monocytogenes biofilm formed on stainless steel and glass surfaces, which suggested that SAEW could remove L. monocytogenes biofilm effectively and its disinfection efficacy is equal to (in case of stainless steel) or higher than (in case of glass) that of high ACC of NaClO solutions. In addition, the results of the crystal violet staining and scanning electron microscopy (SEM) also demonstrated that SAEW treatment could remove the L. monocytogenes biofilm on food-contact surfaces.
... In each method of decontamination, limitations can be found. For example, ozone can cause the rancidity of fat and muscle pigments in meat [22][23][24]. Additionally, the health and safety of meat handlers should be considered, including the risk of resistant acid bacteria such as E. coli O157:H7 [25], the corrosive effect of organic acid on meat industry equipment [26,27], and the risk of carcinogenic compounds as trihalomethanes (THMs) from working with chlorine [18,28], as several decontamination methods have been developed to mitigate the negative effects of existing methods. ...
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In this research, we aimed to reduce the bacterial loads of Salmonella Enteritidis, Salmonella Typhimurium, Escherichia coli, Campylobacter jejuni, Staphylococcus aureus, and Pseudomonas aeruginosa in pork and chicken meat with skin by applying cold plasma in a liquid state or liquid plasma. The results showed reductions in S. Enteritidis, S. Typhimurium, E. coli, and C. jejuni on the surface of pork and chicken meat after 15 min of liquid plasma treatment on days 0, 3, 7, and 10. However, the efficacy of the reduction in S. aureus was lower after day 3 of the experiment. Moreover, P. aeruginosa could not be inactivated under the same experimental conditions. The microbial decontamination with liquid plasma did not significantly reduce the microbial load, except for C. jejuni, compared with water immersion. When compared with a control group, the pH value and water activity of pork and chicken samples treated with liquid plasma were significantly different (p ≤ 0.05), with a downward trend that was similar to those of the control and water groups. Moreover, the redness (a*) and yellowness (b*) values (CIELAB) of the meat decreased. Although the liquid plasma group resulted in an increase in the lightness (L*) values of the pork samples, these values did not significantly change in the chicken samples. This study demonstrated the efficacy of liquid plasma at reducing S. Enteritidis, S. Typhimurium, E. coli, C. jejuni, and S. aureus on the surface of pork and chicken meat during three days of storage at 4–6 °C with minimal undesirable meat characteristics.
... log CFU/cm 2 on day 0, and 0.65-1.36 log CFU/cm 2 on day 7. Rahman, Wang, and Oh (2013) proved that the treatment with the combination of NEW (ACC = 10 mg/L, pH = 6.8, and ORP = 700 mV) and calcium lactate (CaL, 3%) for 5 min at 23 • C caused 3.0-3.2 log CFU/g reduction of E. coli and L. monocytogenes inoculated on the pork that was pretreated by UV light. ...
With the growing demand for safe and nutritious foods, some novel food nonthermal sterilization technologies were developed in recent years. Electrolyzed oxidizing water (EOW) has the characteristics of strong antimicrobial ability, wide sterilization range, and posing no threat to the humans and environment. Furthermore, EOW can be used as a green disinfectant to replace conventional production water used in the food industry since it can be converted to the ordinary water after sterilization. This review summarizes recent developments of the EOW technology in food industry. It also reviews the preparation principles, physical and chemical characteristics, antimicrobial mechanisms of EOW, and inactivation of toxins using EOW. In addition, this study highlights the applications of EOW in food preservation and safety control, as well as the future prospects of this novel technology. EOW is a promising nonthermal sterilization technology that has great potential for applications in the food industry.
... Hypochlorous acid is the most active of the chlorine compounds and has high bactericidal activity (36). In several studies, the efficacy of NEW has been evaluated for reduction of bacterial population in fresh meat (12,35,42,43), eggshells (44), seafoods (28), and vegetables (1). If NEW were to be combined with other chemical disinfectants such as organic acids, its antimicrobial efficacy might increase. ...
This study was conducted to evaluate the antimicrobial efficacy of near-neutral electrolyzed water (NEW) and peroxyacetic acid (PAA) alone and in combination for reducing the foodborne pathogens Salmonella Typhimurium, Escherichia coli, and Listeria monocytogenes in pure culture and fresh chicken meat. The NEW treatments resulted in 100% inactivation of these organisms in pure culture at concentrations of 50, 100, and 200 μg/mL and 2 min of contact time at room temperature. The PAA treatments at concentrations of 100 and 200 μg/mL resulted in 100% inactivation of the tested pathogens. The combination of NEW and PAA had a greater bactericidal effect than did each individual treatment. The inoculated chicken meat samples were dipped for 10 min in each treatment solutions (100 and 200 μg/mL NEW, 200 and 400 μg/mL PAA, 100 μg/mL NEW + 200 μg/mL PAA) at room temperature. Samples dipped in water were used as a control. The greatest reduction was achieved with the combined treatment, which significantly (P < 0.05) reduced total cells and healthy cells of Salmonella Typhimurium, E. coli, and L. monocytogenes by 2.79 and 3.01, 2.63 and 2.75, and 1.47 and 1.99 log CFU/g, respectively. The findings of this study indicate that a combined treatment with NEW and PAA has potential as a novel antimicrobial agent to improve the microbial safety of fresh chicken meat. © 2021, International Association for Food Protection. All rights reserved.
... Moreover, SAEW and sodium hypochlorite treatment have an equivalent disinfection efficacy in fresh-cut cilantro, spinach, and cut cabbage samples (Koide et al., 2009;Rahman et al., 2010;Hao et al., 2011). Furthermore, Rahman et al. (2013) and Wang et al. (2014) demonstrated that SAEW treatment can be utilized to disinfect fresh shrimp and pork. Based on these experimental results, the United States Environmental Protection Agency (EPA) has approved the use of EW generators for disinfection in the food processing field. ...
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To consistently disinfect fresh vegetables efficiently, the decay of disinfectants such as chlorine, electrolyzed oxidizing water (EOW), ozonated water, and plasma-activated water during the disinfection maintenance stage needs to be understood. The aim of our study was to evaluate the changes in the inactivation kinetics of slightly acidic electrolyzed water (SAEW) against human norovirus (HuNoV), based on the cabbage-to-SAEW ratio. After disinfection of fresh cabbage with disinfected SAEW solution, SAEW samples were collected and analyzed for physicochemical properties such as pH, available chlorine concentrations (ACCs), and oxidation-reduction potential (ORP). SAEW virucidal effects were evaluated. We confirmed the decay of post-disinfection SAEW solution and demonstrated the different patterns of the decay kinetic model for HuNoV GI.6 and GII.4. In addition, the goodness of fit of the tested models based on a lower Akaike information criterion, root-mean-square error (RMSE), and residual sum of squares (RSS) was close to zero. In particular, the change in both the HuNoV GI.6 and GII.4 inactivation exhibited a strong correlation with the changes in the ACC of post-disinfection SAEW. These findings demonstrate that physicochemical parameters of SAEW play a key role in influencing the kinetic behavior of changes in the disinfection efficiency of SAEW during the disinfection process. Therefore, to optimize the efficiency of SAEW, it is necessary to optimize the produce-to-SAEW ratio in future studies.
... However, potatoes washed at 60 • C with US treatment have shown color changes [29]. Other studies have reported that dipping in electrolyzed water for 3 min has the best sanitizing effect [31][32][33]. The present study also showed that washing for 3 min with SAEW + US at 10 times the sample volume at 25 • C was the most effective treatment condition to reduce the population of EPEC in fresh-cut carrot. ...
Full-text available
We investigated the combined effect of using slightly acidic electrolyzed water (SAEW), ultrasounds (US), and ultraviolet-C light-emitting diodes (UV-C LED; 275 nm) for decreasing pathogenic Escherichia coli and Staphylococcus aureus (SEA) in fresh-cut vegetables, including carrots, celery, paprika, and cabbage. Survival of pathogenic E. coli and SEA and quality properties of fresh-cut vegetables at 5 and 15 °C for 7 days were also investigated. When combined treatment (SAEW + US + UV-C LED) was applied to fresh-cut vegetables for 3 min, its microbial reduction effect was significantly higher (0.97~2.17 log CFU/g) than a single treatment (p < 0.05). Overall, the reduction effect was more significant for SEA than for pathogenic E. coli. At 5 °C, SAEW + US and SAEW + US + UV-C LED treatments reduced populations of pathogenic E. coli and SEA in all vegetables. At 15 °C, SAEW + US + UV-C LED treatment inhibited the growth of both pathogens in carrot and celery and extended the shelf life of fresh-cut vegetables by preventing color changes in all vegetables. Although the effects of treatments varied depending on the characteristics of the vegetables and pathogens, UV-C LED can be suggested as a new hurdle technology in fresh-cut vegetable industry.
Food safety is a burning issue in the present world. Safe sanitizers are obligatory for maintaining quality of food and increasing the shelf life of fresh produce and other agricultural products. Food industries have been using electrolyzed water (EW) as a unique sanitizer for the past two decades which has excellent results to reduce the microbial count. Hurdle technology, e.g., combination of EW with ultrasonication, short-term heat treatment, organic acids, and salts, found to have more effective results in reducing microorganisms which overcame the little shortcomings with EW like corrosiveness and maintained organoleptic qualities. In this chapter, we are going to discuss the production of EW and its combination with ultrasonication, short-term heat treatment, organic acids, and salts to produce a novel sanitizer.
Full-text available
Electrolyzed water (EW) has been proposed as a novel promising sanitizer and cleaner in recent years. It is an effective antimicrobial and antibiofilm agent that has several advantages of being on the spot, environmentally friendly, cheap, and safe for human beings. Therefore, EW has been applied widely in various fields, including agriculture, food sanitation, livestock management, medical disinfection, clinical, and other fields using antibacterial technology. Currently, EW has potential significance for high-risk settings in hospitals and other clinical facilities. The research focus has been shifted toward the application of slightly acidic EW as more effective with some supplemental chemical and physical treatment methods such as ultraviolet radiations and ultrasound. This review article summarizes the possible mechanism of action and highlights the latest research studies in antimicrobial applications.
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Goat meat is the main source of animal protein in developing countries, particularly in Asia and Africa. Goat meat consumption has also increased in the US in the recent years due to the growing ethnic population. The digestive tract of goat is a natural habitat for Escherichia coli organisms. While researchers have long focused on postharvest intervention strategies to control E. coli outbreaks, recent works have also included preharvest methodologies. In goats, these include minimizing animal stress, manipulating diet a few weeks prior to processing, feeding diets high in tannins, controlling feed deprivation times while preparing for processing, and spray washing goats prior to slaughter. Postharvest intervention methods studied in small ruminant meats have included spray washing using water, organic acids, ozonated water, and electrolyzed water, and the use of ultraviolet (UV) light, pulsed UV-light, sonication, low-voltage electricity, organic oils, and hurdle technologies. These intervention methods show a strong antimicrobial activity and are considered environmentally friendly. However, cost-effectiveness, ease of application, and possible negative effects on meat quality characteristics must be carefully considered before adopting any intervention strategy for a given meat processing operation. As discussed in this review paper, novel pre- and post-harvest intervention methods show significant potential for future applications in goat farms and processing plants.
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In order to extend meat shelf-life, normal-pH and high-pH beef steaks were packaged under vacuum or in 100% C 0 2 atmosphere. Microbiological, colour (L*, a*, b*)and reflectance (R630-R580 values) characteristics were measured.After packaging under vacuum, Enterobacteriaceae, Brochothrix thermosphacta and Pseudomonas numbers were 10- to 100-fold greater on high-pH meat than onnormal-pH meat.Packaging under C 0 2 improved the shelf-life of meat, particularly that of high-pH meat up to 42 days. For both high- and normal-pH meats, the bacterial flora wascomposed only of lactic acid bacteria. Normal-pH meat in C 0 2 atmosphere and vacuum packaging had a purple colour. After C02-pack opening the meat colourbecame bright red and R630- R580 measurements were high, whereas after opening of vacuum packaging R630-R580 decreased rapidly with increasing aerobic exposure.High-pH meat became paler with increasing storage time in C02. Simultaneously R630-R580 values increased and the pH fell. In addition it lost less exudate andoxidized less in air than the normal-pH meat under the same conditions.
Microbiological processes by which meat develops qualities unacceptable to consumers vary with the composition of the meat and spoilage microflora. Composition of the spoilage microflora is affected by meat composition and storage conditions. Aerobic spoilage microfloras are usually dominated by pseudomonads. With this type of microflora, spoilage occurs when glucose in meat is no longer sufficient for the requirements of the spoilage microflora and the bacteria start to degrade amino acids. When meat is deficient in glucose, spoilage becomes evident while bacterial numbers are relatively small. Anaerobic microfloras are usually dominated by lactobacilli which produce spoilage by the slow accumulation of volatile organic acids. Meat of high utimate pH packaged anaerobically spoils rapidly because the high pH allows anaerobic growth of bacterial species of higher spoilage potential than the lactobacilli. Before overt spoilage develops, the spoilage status of meat can be accurately assessed from the bacteri...
In this paper, we report the results of treating commercial samples of pork meat with ozone in order to determine whether such treatment reduces microbial growth and hence extends the shelf lifetime of such products. The technique of Proton-Transfer-Reaction Mass Spectrometry (PTR-MS) was used to study volatile emissions with the signal detected at mass 63 (assumed to be a measure for dimethylsulphide) being used as a diagnostic of bacterial activity. Such a signal was found to strongly increase with time for an untreated meat sample whereas ozone-treated meat samples showed much reduced emissions—suggesting that the microbial activity had been greatly suppressed by ozone treatment. An independent analysis, however, revealed that microbial counts were very high, independent of the treatment.
The efficacy of organic acids for controlling Escherichia coli O157:H7 attached to beef carcass tissue was determined using a pilot scale model carcass washer. Lean or adipose surface tissues from beef carcasses were inoculated with three strains of Escherichia coli O157:H7 or Pseudomonas fluorescens. After spraying eithher water, 1, 3, or 5% acetic, lactic, or citric acids at 24°C, tissues were incubated for 24 h at 4°C and bacterial populations enumerated. Statistical analyses of the data indicated that acid type was not a significant treatment factor (p ≥ = 0.05); however, concentration, tissue type, and bacterial strain were significant (p ≤ = 0.0001 ) factors that influenced the reduction of bacterial populations on lean or adipose tissue. Of the concentrations tested on lean tissue, spray treatments with 5% were the most effective for reducing populations of E. coli O157:H7 or P. fluorescens. Differences in the resistances of the E. coli O157:H7 strains to acid washing also were observed. The magnitude of bacterial population reductions was consistently greater on adipose versus lean tissue for all bacterial strains. Surface pH data indicated that reductions of bacterial populations may have been due to the effects of acidic pH. This study demonstrates that, while organic acids did reduce populations of E. coli O157:H7 on red meat, treatments did not completely inactivate the pathogen.
Microbiological and some physical and chemical effects of treating pork chop surfaces with sodium acid pyrophosphate, a commercial phosphate blend, potassium sorbate and phosphate/sorbate/sodium acetate solutions, with or without sodium chloride, before packaging were studied in pork chops vacuum-packaged and stored at 2–4°C for 10 weeks. All treatments containing potassium sorbate reduced (P<0.05) counts of mesophiles, psychrotrophs, EnterobacteriaCeae, facultative anaerobes, and lactobacilli. Treatment of chops with 10% phosphates/ 10% potassium sorbate solutions improved pork color and decreased purge. Potassium sorbate alone reduced microbial counts more than it did when combined with phosphates, but chops were darker and had more exudate (P<0.05). Combined use of 10% phosphates/10% potassium sorbate extended shelf life in vacuum-packaged fresh pork chops to 10 weeks at 2–4°C compared with 4 weeks for untreated pork and protected meat color.
The effects of MAP and/or pretreatment with lactic acid buffer were studied on the shelf-life of broiler carcasses, under conditions simulating market storage (4 and 7°C) in the State of Kuwait. Pretreatment with lactic acid buffer increased treated carcass shelf-life by 6–7 days when stored at 4°C and 5–6 days at 7°C. Likewise, pretreatment of MAP carcasses with the same buffer extended the shelf-life to >36 and 35 days, compared with 22 and 13 days for the untreated MAP carcasses. Pretreatment of poultry with lactic acid buffer, with or without MAP, provides a potential alternative for improving the storage quality of poultry.