Ji Yeol Yoon1,2, Dongwook Kim1, Eun-Bae Kim1, Sung-Ki Lee1, Mooha Lee3, Aera Jang1. 1. Department of Applied Animal Science, College of Animal Life Science, Kangwon National University, Chuncheon 24341, Korea. 2. R&D Center, Paldo Co. Ltd., Yongin 17086, Korea. 3. Korean Academy of Science & Technology, Seongnam 13630, Korea.
Abstract
We investigated the quality properties and bacteria diversity of pork salami containing homemade kimchi powder (KP). Pork salamis were manufactured with commercial starter culture (control), and 1% KP (KP1), 3% KP (KP3), and 5% KP (KP5). The salami was fermented and aged for 2 days and 56 days, respectively. The pH and AW values of salamis with KP were significantly lower than that of the control (p<0.05). The 2-thiobarbituric acid reactive substance values of all salamis with KP increased but were below 0.2 mg MDA/kg. Salamis with KP, decreased the L* value, but increased the a* and b* values (p<0.05). The Lactobacillus count was significantly higher in the salamis with KP than in the control by day 14 (p<0.05). The number of Leuconostoc was higher in salamis with KP than in the control and was the highest in salamis in KP1. The KP1 protected lipid oxidation and showed low TBARS value of pork salami compared to the control. This study demonstrates that KP can improve pork salami properties and can serve as a potential natural compounds for fermented meat prodcuts like Metzgerei.
We investigated the quality properties and bacteria diversity of pork salami containing homemade kimchi powder (KP). Pork salamis were manufactured with commercial starter culture (control), and 1% KP (KP1), 3% KP (KP3), and 5% KP (KP5). The salami was fermented and aged for 2 days and 56 days, respectively. The pH and AW values of salamis with KP were significantly lower than that of the control (p<0.05). The 2-thiobarbituric acid reactive substance values of all salamis with KP increased but were below 0.2 mg MDA/kg. Salamis with KP, decreased the L* value, but increased the a* and b* values (p<0.05). The Lactobacillus count was significantly higher in the salamis with KP than in the control by day 14 (p<0.05). The number of Leuconostoc was higher in salamis with KP than in the control and was the highest in salamis in KP1. The KP1 protected lipid oxidation and showed low TBARS value of pork salami compared to the control. This study demonstrates that KP can improve pork salami properties and can serve as a potential natural compounds for fermented meat prodcuts like Metzgerei.
Fermented meat products are known to contain bioactive substances. Fermented
sausages, a traditional food of Europe, are made from the fermentation of lactic
acid bacteria (LAB) and are produced under controlled temperature and relative
humidity conditions (Coloretti et al., 2014).
Fermented sausages are generally produced without any heat treatment throughout the
process of fermentation, aging, and drying (Paik and
Lee, 2014). The manufacturing process of fermented sausages has two main
steps: fermentation and aging, of which fermentation is the most important. During
fermentation and aging, microbial changes to the LAB composition, and chemical
changes such as the production of flavor compounds, result from the degradation of
proteins and lipids (Ko and Yang, 1999). The
typical characteristics of fermented sausages are a product of the biochemical and
physical changes that resulted during fermentation and aging. In addition, these
meats cannot be pasteurized, and are therefore highly vulnerable to the growth of
undesirable microorganisms. Therefore, the selection of favorable conditions that
encourage the growth of desirable and safe microflora, and restrict the growth of
spoiling bacteria, is essential for the shelf-life extension of fermented sausages
(Aro et al., 2010; Park and Lee, 2012).Kimchi, a traditional fermented food of Korea, is a very popular side dish and
manufactured from the addition of various components, including ginger, red pepper,
green onion, garlic, fermented shrimp, or fish. The antimicrobial activity of kimchi
has been reported by many scientists (Park et al.,
2011) that various LAB, including Pediococcus spp.,
Leuconostoc spp., Lactobacillus spp., and
Weissella spp., participate in the fermentation, and
Pediococcus pentosaceus, a LAB derived from kimchi, produces a
bacteriocin called pediocin, which has antimicrobial activity (Jang et al., 2014). LAB are used to preserve fermented food
products such as dairy foods, vegetables, and meats, and are vital in meat
fermentation (Lee et al., 2006). The major
role of LAB is to produce lactate rapidly and reliably from the sugars, usually
glucose and sucrose, that are added to the sausage mix (Ahmad and Srivastava, 2007). Growth of LAB can inhibit the
growth of pathogenic and spoilage bacteria in a number of ways, including the
production of a wide range of inhibitory substances like lactic acid, diacetyl, and
bacteriocins, and competition for attachment or adhesion (Hugas, 1998). El-Adawy
(2001) showed that the addition of Pediococcus
pentosaceus to food products is crucial, not only for its fermentative
role, but also for its suppressive effect on the growth of undesirable and
pathogenic microorganisms. Leuconostoc mesenteroides is primarily
involved in initial fermentation and produced lactic acid and carbon dioxide (Lee et al., 1990; Park and Cheigh, 2000). Mcdonald et al. (1990) reported that Leuconostoc
mesenteroides grows during early fermentation and that
Lactobacillus plantarum terminates the fermentation.
Pediococcus pentosaceus and Leuconostoc
mesenteroides converts sucrose into dextran by dextransucrase and is
used in the fermentation of sausages because it prevents the growth of pathogenic
bacteria (Jo et al., 2008; Shukla and Goyal, 2013).The microbial composition of kimchi has been identified using conventional methods,
but these studies used limited types of media and culture conditions and would have
missed bacteria that are unculturable under general laboratory conditions (Kim and Chun, 2005). A few studies have allowed
for the characterization of the microbial community in kimchi using traditional
culture-dependent and independent methods, such as polymerase chain reaction (PCR),
ribosomal DNA restriction analysis (ARDRA), and denaturing gradient gel
electrophoresis (DGGE) (Park and Lee, 2012).
The 16S rRNA gene of microorganisms have specific sequence and differ between
species and allows identification of bacteria to the genus level (Han et al., 1998).The objectives of the present study were to evaluate the effect of kimchi powder
levels as a starter on the quality characteristics and microbial diversity of pork
salami during fermentation and aging.
Materials and Methods
Preparation of kimchi powder (KP)
Chinese cabbage kimchi was manufactured with following procedure and the
ingredients according to one of traditional methods for kimchi in Jelanamdo.
Chinese cabbages were dipped in brine for 8 h, then washed with tap water and
drained. The brined Chinese cabbages were mixed with the following seasoning and
spices: white radish (10.0%), chives (1.0%), mustard leaves (1.0%), glutinous
rice gruel (6.0%), red pepper powder (3.0%), sand lance sauce (0.5%), salted
shrimp (0.5%), fresh shrimp (0.5%), plum extracts (1.0%), garlic (1.0%), ginger
(0.5%), salt (0.5%), and 9.0% broth. The broth was extract from 2.5% dried
pollack head, 0.5% large-eyed herring, 5.0% onion, 0.2% kelp, 1.0% spring onion
in 1 L of water. The kimchi and seasoning mixture was ripened for 14 days at
room temperature (23±1°C). The kimchi mixture was lyophilized in a
vacuum using a freeze-dryer (FDU-1200, Eyela, Japan) and used as KP and stored
at –20°C until further use.
Pork salami preparation
Pork salmi was prepared by the method of Di Cagno
et al. (2008) with slight modification. Fresh ham (66 kg) and pork
back fat (15 kg) were purchased from a local market and kept below 4°C
during preparation. Fresh ham and pork back fat were ground using a meat chopper
(M-22, Daewoo Kitchen Co., Korea) with a disc of 6 mm diameter. Pork salamis
were manufactured with the following formulation; 85.00% fresh ham, 15.00% pork
back fat, 2.00% salt, 0.26% prague powder, 1.00% sucrose, 0.05% sodium
erythorbate, 0.75% dextrose, 0.35% whole mustard seed, 0.70% black pepper, 0.30
% garlic powder, 0.06% ground ginger, 0.06% nutmeg, 1.00% carrageenan, and 0.10%
smoke solution. Freeze-dried KP was mixed with pork salami batter at the levels
of 1% (KP1), 3% (KP3) and 5% (KP5). Salt was added to sausages to adjust
according to the salt content of KP (12.17%), resulting in a salt content for
each treatment of 2.00% for the control, 1.88% for KP1, 1.65% for KP3, and 1.42%
for KP5. The control sausage was manufactured using a commercial starter culture
(Lyocarni SBM-52, Clerici Sacco Co., Cadorago, Italy), which consists of
Staphylococcus carnosus, Staphylococcus
xylosus, Pediococcus pentosaceus, and
Pediococcus acidilactici. After mixing with the starter
culture, the salami meat batters were stuffed into collagen casings. Then it was
transferred to a chamber controlling temperature and humidity under the
conditions shown in Table 1.
Table 1
Conditions in the humidity chamber during fermentation and ageing of
the pork salami added with kimchi powder
Time (d)
Process
Condition
Temperature (°C)
Humidity (%RH)
0
Conditioning
25
65
1
Fermentation
23
95
2
Fermentation
23
92
3
Ageing
20
90
5–56
Ageing
10
75
Proximate composition, pH and water activity (AW) of pork
salami
The proximate composition of salamis was measured according to the methods of
AOAC (1995). The moisture content of
salamis was measured by weight loss after 12 h of drying at 105°C (method
940.26). The protein content was measured using the Kjeldahl method (method
920.152). The salt content was measured by titration using the Mohr method
(Kirk and Sawyer, 1991). The pH
values of pork salamis were measured by first blending 10 g of pork salami with
90 mL distilled water for 30 s with a homogenizer (PolyTron ® PT-2500E,
Kinematica, Switzerland), and probing with a pH meter (Orion 230A, USA).
AW of pork salamis was measured using an aquaspector (AQS-2-TC,
NAGY, Germany).
Color and texture profile analysis (TPA)
Color measurements were conducted with a color meter (CR-300, Minolta Co.,
Japan). The instrument was calibrated with white tiles. L* value (lightness), a*
value (redness), and b* value (yellowness) were determind on the surface of
samples (n=10). The colorimeter was calibrated using white standard plate
(Y=93.60, x=0.3134, and y=0.3194).Texture profile was measured at room temperature (23°C) with a texture
analyzer (TA-1, LLOYD Instruments, USA). The test conditions were as follows:
with 50 mm diameter probe, compression speed 10 mm/min, wait time 5 s, trigger
0.01 kgf, sample compressed 70%. Pork salamis were cut into sections of 1.0 cm
in height and 1.0 cm in width. Data for the hardness (kgf), adhesiveness (Nmm),
gumminess (kgf), chewiness (kgf), and cohesiveness were collected and
analyzed.
Thiobarbituric acid reaction substances (TBARS)
The lipid oxidation in pork salamis was determined according to the water vapor
distillation method of Witte et al.
(1970). A sample of 10 g was placed in a conical tube, to which a 25
mL solution of 20% trichloroacetic acid (TCA) was added and homogenized for 30 s
at 14,000 rpm using a homogenizer (Polytron® PT-2500E,
Kinematica, Switzerland). The resulting slurry was transferred to a mass
cylinder and diluted to 50 mL with distilled water. The sample was filtered
through Whatman No. 1 filter paper. Then, 5 mL of the filtrate was transferred
to a test tube, and 5 mL of fresh chilled 0.005 mM 2-thiobarbituric acid
solution was added. All samples in test tubes were kept in the dark for 15 h at
room temperature. The absorbance of color was determined in a UV/VIS
spectrophotometer (M2e, Molecular Devices, USA) at 530 nm and calculated by
following equation.
Lactic acid bacteria (LAB) and microbial analysis
For LAB, 10 g of salami sample was homogenized in 90 mL 0.1% peptone water for 4
min in a stomacher (Bag Mixer 400, Interscience, France). A 10-fold serial
dilution was made, of which 100 μL samples of appropriate dilutions were
spread on Lactobacilli MRS agar (Difco Laboratories, USA) and
incubated at 35°C for 48 h. In addition, total microorganisms and
E. coli/coliforms were counted using petrifilm (Aerobic
count plate, Coliform count plate, 3M, USA) after incubation at 37°C for
48 h. DNA was extracted from pork salami containing kimchi and kimchi-powder
itself using a DNA kit (Macherey-Nagel GmbH and Co. KG, Germany). The 16S rRNA
genes of extracted DNA were amplified on a Trio-Thermoblock thermocycler
(Biometra, Germany). Each PCR was set in a volume of 23.5 μL with 17.85
μL sterile distilled water, 2.5 μL 10× PCR buffer, 0.5
μL MgCl2, 2.0 μL dNTP mix, 0.15 μL Ex-Taq
polymerase (Takara, Japan), 0.5 μL each of forward and reverse primers
(10 pmoles), and 1.0 μL purified DNA (5 ng/ μL). Thermocycling
conditions were as follows: 3 min at 94°C for initial denaturation;
followed by 30 cycles of 45 s at 94°C, 1 min at 55°C and 1.5 min
at 72°C; and final extension for 10 min at 72°C, after which the
PCR mixture was cooled to 4°C. Amplification products were analyzed by
electrophoresis at 135 V for 30 min on a 2% agarose gel in 0.5× TAE
buffer. PCR products were sequenced using the Miseq sequencer system (Illumina,
USA).
Sensory evaluations
Thirteen panelists from the Department of Animal Product and Food Science at
Kangwon National University in Korea provided sensory evaluations of the
sausages (n=13). Pork salamis were cut and served to the panelists in random
order. The sensory properties of the pork salami were evaluated for color,
appearance, specific odor, flavor, acidity, preference, texture, and overall
acceptability using a 9-point descriptive scale: color (1=extremely undesirable,
9=extremely desirable), appearance (1=extremely undesirable, 9=extremely
desirable), specific odor (1=extremely undesirable, 9=extremely desirable),
flavor (1=extremely undesirable, 9=extremely desirable), acidity (1=weak
acidity, 9=strong acidity), preference (1=extremely undesirable, 9=extremely
desirable), texture (1=extremely tough, 9=extremely tender), and overall
acceptability (1=extremely undesirable, 9=extremely desirable).
Statistical analysis
All data collected were subjected to one-way analysis of variance (ANOVA)
according to the general linear model procedures for SAS software (ver. 9.2. SAS
Institute Inc., USA). Mean values and standard error of the mean value of sample
were reported. When analysis of variance indicated a significant treatment
effect, Tukey's test was used to compare the mean values, and a p-value
<0.05 was considered statistically significant.
Results and Discussion
Physicochemical properties of pork salami containing kimchi powder
(KP)
The proximate compositions of pork salami containing KP are presented in Table 2. Until day 35 of aging period, the
moisture content of the pork salamis decreased while the crude protein and crude
fat contents of the salamis increased significantly (p<0.05). There was
no significant difference in crude ash composition between sausages. The
moisture content rapidly decreased between the initial phase (60.43% to 62.26%)
and aging day 21 (37.60% to 39.27%) in all pork salamis and were significantly
lower at day 56 (30.61–32.05). The crude protein contents of all pork
salamis were increased by the end of storage and showed 22.46%–23.87% at
initial phase and 44.93%–48.21% at the end of aging (p<0.05). In
addition, Lee et al. (2008) demonstrated
that breakfast sausages with hot air-dried KP had significantly higher water
content than without KP. The crude fat content of pork salamis in KP1 increased
from 12.83% to 22.94% until day 28.
Table 2
Proximate compositions of pork salamis added with different level of
kimchi powder
Items
Treatments[1)]
Days
0
7
14
21
28
35
42
49
56
SEM
Moisture
CON
62.26[Aa]
52.15[Bb]
44.13[Ac]
39.27[Ad]
33.39[Be]
30.99[Cfg]
31.22[Af]
30.97[Cfg]
30.61[Cg]
0.164
KP1
62.10[Aa]
53.68[Ab]
42.93[Bc]
37.60[Bd]
33.32[Be]
31.92[ABf]
31.55[Afg]
31.03[Cg]
31.12[BCg]
0.223
KP3
62.26[Aa]
53.42[Ab]
43.69[ABc]
37.68[Bd]
33.90[Be]
32.04[Af]
32.09[Af]
32.35[Af]
31.74[ABf]
0.191
KP5
60.43[Ba]
52.74[Bb]
44.18[Ac]
37.68[Bd]
34.95[Ae]
31.44[BCf]
31.96[Af]
31.69[Bf]
32.05[Af]
0.274
SEM
0.171
0.187
0.280
0.178
0.265
0.176
0.263
0.152
0.236
Crude protein
CON
22.52[Ag]
27.38[Af]
33.89[Ae]
36.15[Bd]
40.29[Ac]
41.72[Abc]
42.49[b]
42.03[Bbc]
47.23[ABa]
0.621
KP1
22.48[Af]
26.41[Ae]
35.22[Ad]
38.59[ABc]
40.43[Abc]
41.14[Ab]
41.37[Ab]
41.96[Bb]
48.21[Aa]
0.792
KP3
22.46[Ae]
28.65[Ad]
35.25[Ac]
38.28[ABc]
41.42[Ab]
42.67[Ab]
44.39[Aab]
41.91[Bb]
46.57[ABa]
1.055
KP5
23.87[Ae]
27.97[Ad]
34.18[Ac]
39.24[Ab]
40.83[Ab]
44.13[Aa]
44.88[Aa]
45.64[Aa]
44.93[Ba]
1.018
SEM
0.811
0.819
0.858
0.816
0.453
1.118
1.088
1.034
0.824
Crude fat
CON
12.86[Ad]
18.05[Ac]
19.66[Ac]
21.92[Ab]
23.67[Aab]
24.02[Aa]
24.02[Aa]
24.54[Aa]
19.67[Ac]
0.611
KP1
12.83[Ae]
16.99[ABd]
18.88[Ac]
20.94[Ab]
22.94[ABa]
23.16[Aa]
22.86[ABa]
22.22[ABab]
18.41[Acd]
0.571
KP3
12.83[Ad]
15.37[Bd]
18.21[Ac]
21.17[Aab]
21.83[Bab]
21.48[Aab]
19.83[Babc]
22.48[Aa]
19.38[Abc]
0.895
KP5
13.37[Ac]
16.52[ABb]
18.88[Aab]
20.53[Aa]
21.63[Ba]
21.13[Aa]
19.88[Ba]
19.26[Ba]
20.38[Aa]
0.845
SEM
0.616
0.724
0.706
0.481
0.431
0.933
0.912
0.919
0.783
Crude ash
CON
2.35[Aa]
2.42[Aa]
2.33[Aa]
2.65[Aa]
2.65[Aa]
3.27[Aa]
2.27[Aa]
2.46[Ba]
2.65[Aa]
0.379
KP1
2.59[Ab]
2.93[Ab]
2.97[Ab]
2.87[Ab]
3.30[Aab]
3.78[Aab]
4.22[Aab]
4.79[Aa]
4.62[Aab]
KP3
2.46[Aa]
2.33[Aa]
2.85[Aa]
2.87[Aa]
2.85[Aa]
3.81[Aa]
3.69[Aa]
3.73[ABa]
2.44[Aa]
0.596
KP5
2.34[Ab]
2.77[Aab]
2.76[Aab]
2.54[Aab]
2.60[Aab]
3.30[Aab]
3.28[Aab]
3.41[ABa]
2.64[Aab]
0.304
SEM
0.391
0.341
0.334
0.492
0.241
0.791
0.591
0.502
A–C Means within same column with different
superscript letters differ significantly at p<0.05.
a–g Means within same row with different
superscript letters differ significantly at p<0.05.
1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
A–C Means within same column with different
superscript letters differ significantly at p<0.05.a–g Means within same row with different
superscript letters differ significantly at p<0.05.1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.The changes in pH values and Aw of pork salamis with KP were shown in Table 3. The pH values of all pork salamis
in KP1 were decreased significantly from day 1 to at the end of the aging
period. The pH values of all pork salamis varied from 5.62–5.71 to
4.41–4.60 during aging period. Muguerza
et al. (2002) observed a similar change in pH of fermented sausages
with 10%, 20% and 30% pork back fat, and reported that the initial pH values of
fermented sausages ranged from 6.03 to 6.29 and the final pH values on the 28th
day ranged from 4.70 to 4.92. According to Campagnol et al. (2011), the reduction in pH values in fermenting
sausage prior to the 14th day of production is caused by the accumulation of
lactic acid from LAB metabolizing carbohydrates such as sucrose and glucose. The
pH of fermented sausages rapidly declined to 4.8–4.9 by day 4, decreased
somewhat more (pH 4.5–4.6) by the end of the fermentation (day 7), and
maintained at this pH level during ripening periods (Chouliara et al., 2006). These results are similar to the
present results. Another study found that pH values of fermented sausages with
added kimchi were 5.53–5.54 at day 0, and were 4.30–4.33 at day 3
(Kang et al., 2012). Park and Lee (2012) reported that LAB
reduce pH values through the utilization of carbohydrates and production of
organic acids, and LAB counts reach their maximum values between day 1 and day
2. The pH values of the pork salami with KP were lower than that of the control
and ranged from 4.41 to 4.51 at end of aging period. These results reveal that
the higher the concentration of KP, the lower the pH value of pork salami. It
was apparent that acidification in the KPs was stronger than that in the control
sausage. The reduction in the pH value below 5.0 was due to LAB and helps to
reduce the aging time by the promotion of dryness and to increase shelf life by
the inhibition of spoilage microorganisms.
Table 3
The changes in pH and AW value of pork salami added with
different level of kimchi powder
Items
Treatments[1)]
Days
0
1
2
3
5
7
14
21
28
35
42
49
56
SEM
pH
CON
5.71[ABa]
5.72[Da]
5.03[Cb]
4.85[Ac]
4.84[Ad]
4.75[Ae]
4.69[Af]
4.66[Ag]
4.64[Ag]
4.65[Ag]
4.65[Ag]
4.51[Ai]
4.60[Ah]
0.006
KP1
5.74[Ab]
5.88[Aa]
5.15[Ac]
4.75[Bd]
4.65[Be]
4.60[Bf]
4.61[Bf]
4.54[Bg]
4.51[Bh]
4.50[Bh]
4.52[Bgh]
4.38[Bi]
4.51[Bh]
0.007
KP3
5.68[Bb]
5.86[Ba]
5.07[Bc]
4.70[Dd]
4.64[Ce]
4.53[Cf]
4.53[Cfg]
4.51[Cg]
4.51[Bg]
4.44[Ci]
4.47[Dh]
4.35[Dk]
4.42[Cj]
0.007
KP5
5.62[Cb]
5.76[Ca]
5.14[Ac]
4.73[Cd]
4.62[De]
4.53[Cf]
4.52[Cfg]
4.50[Cgh]
4.48[Bi]
4.49[Bhi]
4.50[Cghi]
4.36[Ck]
4.41[Cj]
0.007
SEM
0.013
0.005
0.010
0.003
0.005
0.004
0.003
0.009
0.010
0.003
0.004
0.004
0.006
Aw
CON
0.928[Bd]
0.940[ABbc]
0.946[ABa]
0.941[ABb]
0.936[Bc]
0.932[Ad]
0.931[Ad]
0.881[ABe]
0.848[Bf]
0.837[Bg]
0.829[Ah]
0.846[Bf]
0.820[Bi]
0.001
KP1
0.938[Ab]
0.945[Aa]
0.947[Aa]
0.945[Aa]
0.944[Aa]
0.933[Ac]
0.918[Bd]
0.883[Ae]
0.855[ABf]
0.841[ABg]
0.826[ABh]
0.837[Cg]
0.830[Ah]
0.002
KP3
0.940[Aab]
0.939[ABab]
0.944[ABa]
0.939[Bab]
0.936[Bbc]
0.932[Ac]
0.916[Bd]
0.878[ABe]
0.860[Af]
0.845[Ag]
0.826[ABi]
0.851[Ag]
0.834[Ah]
0.002
KP5
0.936[Ab]
0.935[Bb]
0.942[Ba]
0.938[Bb]
0.934[Bb]
0.929[Ac]
0.918[Bd]
0.875[Be]
0.858[Af]
0.829[Ch]
0.819[Bi]
0.854[Ag]
0.830[Ah]
0.001
SEM
0.001
0.002
0.001
0.001
0.001
0.002
0.002
0.002
0.002
0.001
0.002
0.001
0.001
A–D Means within same column with different
superscript letters differ significantly at p<0.05.
a–j Means within same row with different
superscript letters differ significantly at p<0.05.
1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
A–D Means within same column with different
superscript letters differ significantly at p<0.05.a–j Means within same row with different
superscript letters differ significantly at p<0.05.1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.The AW of the pork salamis decreased until day 42 (Table 3). The AW values declined
to approximately 0.82 in the control and to approximately 0.83 in pork salami
with KP by the end of aging period. On day 42, the AW values of pork
salami in KP5 were lower than the control. Fermented sausages categorized on the
basis of final AW values, with sausages having an AW value
below 0.90 being termed ‘dry’ and those with an AW
value between 0.90 and 0.95 being considered ‘semi-dry’ (Park et al., 2012). Therefore, all of
sausages in this study were considered dry fermented sausages from day 21. Meat
products with pH between 5.2 and 5.0 or Aw between 0.95 and 0.91, are perishable
(Papadima and Bloukas, 1999). In
addition, sausages with 10% fat, after 14 days of storage in the ripening room,
had pH values and Aw levels lower than 0.90 and 5.0, respectively, which
characterize them as stable in ambient conditions.The TBARS values of pork salamis with KP significantly increased during
fermentation and aging (Fig. 1). TBARS
values generally are used as degree of lipid oxidation, which measures
malonaldehyde contents. The TBARS values of pork salami in control, KP1, KP3,
and KP5 were 0.04, 0.06, 0.11, and 0.13 mg MDA/kg, respectively. The final TBARS
values of control, KP1, KP3 and KP5 were 0.20, 0.11, 0.16 and 0.19 mg MDA/kg,
respectively. However, TBARS values of all pork salamis remained below 0.2 mg
MDA/kg during aging. Kim et al. (2013)
reported that lipid oxidation occurs when the TBARS value is greater than 0.2 mg
MDA/kg. Also, Ahmad and Srivastava (2007)
showed that TBARS value of fermented sausage (control) increased by day 75, and
all samples (below 0.2 mg MDA/kg) were edible by day 60, and within safe limits
by day 75 during refrigerated storage. Based on these results, pork salamis in
this study are considered safe from lipid oxidation.
Fig. 1
TBARS values of pork salami added with different concentrations of
kimchi powder.
A Values with different letters
among treatments differ significantly at p<0.05.
a Values with different
letters during ageing differ significantly at p<0.05. Con, pork
salami added with commercial starter; KP1, pork salami added with 1%
kimchi powder; KP3, pork salami added with 3% kimchi powder; KP5, pork
salami added with 5% kimchi powder; TBARS, Thiobarbituric acid reaction
substances.
TBARS values of pork salami added with different concentrations of
kimchi powder.
A Values with different letters
among treatments differ significantly at p<0.05.
a Values with different
letters during ageing differ significantly at p<0.05. Con, pork
salami added with commercial starter; KP1, pork salami added with 1%
kimchi powder; KP3, pork salami added with 3% kimchi powder; KP5, pork
salami added with 5% kimchi powder; TBARS, Thiobarbituric acid reaction
substances.The textural properties of all pork salamis are listed in Table 4. Cohesiveness of all pork salamis was significantly
decreased (p<0.05). However, hardness, adhesiveness, gumminess, and
chewiness of the salamis were significantly increased during ageing. The
hardness, gumminess, chewiness, and cohesiveness of pork salami with KP
decreased as the concentration of KP increased. The adhesiveness of pork salami
was not affected by the addition of KP.
Table 4
Texture profile analysis of pork salami added with different level of
kimchi powder
Items
Treatment[1)]
Days
7
14
21
28
35
42
49
56
SEM
Hardness(kgf)
CON
4.41[Ah]
5.30[Ag]
5.95[ABf]
7.12[Ae]
9.17[Bd]
10.65[Ac]
11.37[Ab]
12.53[Aa]
0.148
KP1
3.52[Bf]
5.27[Ae]
6.16[Ad]
6.93[Ac]
10.50[Aab]
10.03[Ab]
10.64[Ba]
10.50[Bab]
0.184
KP3
3.40[BCg]
4.74[Bf]
5.67[Be]
6.34[Bd]
9.01[BCb]
8.86[Bbc]
8.42[Cc]
11.05[Ba]
0.174
KP5
3.04[Cc]
3.57[Cc]
4.92[Cb]
5.21[Cb]
8.60[Ca]
8.21[Ba]
8.65[Ca]
8.32[Ca]
0.197
SEM
0.131
0.114
0.115
0.164
0.153
0.254
0.220
0.207
Adhesiveness(Nmm)
CON
0.07[Ad]
0.13[Acd]
0.13[Acd]
0.15[Abc]
0.21[Aab]
0.21[Bab]
0.23[Aa]
0.25[Aa]
0.023
KP1
0.07[Ac]
0.09[Abc]
0.11[Aabc]
0.14[Aabc]
0.13[Aabc]
0.13[Babc]
0.15[Bab]
0.18[Aa]
0.023
KP3
0.07[Ad]
0.10[Acd]
0.13[Abc]
0.15[Aab]
0.16[Aab]
0.16[ABab]
0.18[ABab]
0.20[Aa]
0.014
KP5
0.09[Ac]
0.12[Abc]
0.15[Aab]
0.18[Aa]
0.018[Aa]
0.18[ABa]
0.19[ABa]
0.21[Aa]
0.018
SEM
0.008
0.013
0.017
0.024
0.025
0.017
0.020
0.028
Gumminess(kgf)
CON
2.50[Af]
2.86[Aef]
3.17[Ade]
3.34[Ad]
3.95[Ac]
4.31[Abc]
4.68[Ab]
5.49[Aa]
0.151
KP1
2.14[Bf]
2.67[Ae]
3.08[Ade]
3.23[ABcd]
3.60[ABbc]
4.04[Aab]
4.25[Aa]
4.35[Ba]
0.161
KP3
1.75[Ce]
2.36[Bd]
2.69[Bcd]
2.95[ABbc]
3.11[BCb]
3.13[Bb]
3.23[Bb]
3.75[Ca]
0.128
KP5
1.72[Cd]
1.90[Cd]
2.53[Bc]
2.89[Bbc]
3.04[Cab]
3.11[Bab]
3.25[Bab]
3.33[Ca]
0.129
SEM
0.103
0.094
0.111
0.124
0.163
0.189
0.168
0.162
Chewiness(kgf)
CON
1.70[Ae]
1.82[Ae]
2.24[Ad]
2.72[ABc]
3.31[Ab]
3.54[Ab]
3.57[Ab]
4.10[Aa]
0.111
KP1
1.34[Bf]
1.60[ABe]
2.30[Ad]
2.79[Ac]
3.10[Bb]
3.03[Bbc]
3.05[Bb]
3.48[Ba]
0.085
KP3
1.28[Bd]
1.46[BCd]
1.86[Bc]
2.47[BCb]
2.52[Cb]
2.50[Cb]
2.54[Cb]
3.05[Ca]
0.095
KP5
1.28[Be]
1.31[Ce]
1.86[Bd]
2.34[Cbc]
2.49[Cb]
2.32[BCc]
2.21[Dc]
2.84[Ca]
0.087
SEM
0.072
0.074
0.090
0.086
0.064
0.145
0.077
0.123
Cohesiveness
CON
0.53[Aa]
0.50[Ab]
0.50[Ab]
0.44[Ac]
0.41[Ac]
0.39[Ad]
0.39[Ae]
0.39[Ae]
0.005
KP1
0.54[Aa]
0.50[ABb]
0.50[Ab]
0.45[Ac]
0.42[Ad]
0.38[Be]
0.37[Be]
0.38[Be]
0.004
KP3
0.52[Ba]
0.47[Cb]
0.45[Bc]
0.43[Bd]
0.39[Be]
0.37[Cf]
0.36[BCf]
0.36[Bf]
0.005
KP5
0.48[Ca]
0.49[Cab]
0.45[Bb]
0.43[Bc]
0.39[Bd]
0.37[Ce]
0.35[Cf]
0.35[Cf]
0.004
SEM
0.006
0.006
0.003
0.002
0.004
0.003
0.005
0.004
A–C Means within same column with different
superscript letters differ significantly at p<0.05.
a–h Means within same row with different
superscript letters differ significantly at p<0.05.
1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
A–C Means within same column with different
superscript letters differ significantly at p<0.05.a–h Means within same row with different
superscript letters differ significantly at p<0.05.1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.The CIE L*, a* and b* values of all pork salamis after day 1 decreased
significantly during fermentation and ageing (Table 5). The L* values of all pork salamis were 49.52–57.75
at the initial phase, decreased significantly as ageing progressed, and were the
lowest at end of ageing (31.60–35.09). The a* values of all pork salamis
at the initial phase were 5.49–13.05 and increased at day 1
(11.23–15.97), and then decreased significantly as ageing period
progressed, reaching the lowest at end of ageing period (4.83–10.94). The
b* values of all treatments also decreased significantly from the initial phase
(14.51–30.55) to the final phase (7.88–13.35) and were the lowest
at the end of ageing. The L* value of the control was significantly higher than
that of pork salami with KP on day 7 and 14, and of the L* value of pork salami
with KP decreased as the concentration of KP increased. On the other hand, the
a* and b* values were higher in pork salami with KP than in the control and were
depend on concentration of KP. Lee et al.
(2008) reported that capsaicin, cryptoxanthin, and β-carotene,
in particular those of the carotenoid group, may increase the a* values in pork
salami with KP.
Table 5
Changes in CIE color (L*, a*, and b*) of pork salami added with
different level of kimchi powder
Items
treatment[1)]
Days
0
1
2
3
5
7
14
21
28
35
42
49
56
SEM
L*
CON
57.75[Aa]
57.40[Aa]
48.87[Ab]
48.08[Ac]
44.56[Bd]
40.88[Be]
38.15[Af]
36.62[Ag]
34.90[Ah]
33.11[Bj]
33.76[Ai]
35.01[Ah]
35.09[Ah]
0.156
KP1
56.44[Aa]
52.38[Bb]
46.75[Bd]
47.96[Ac]
47.91[Ac]
42.69[Ae]
37.39[Bf]
36.26[Ag]
34.46[Ah]
33.60[Ai]
33.43[ABi]
33.83[Bhi]
33.18[Bi]
0.272
KP3
52.74[Ba]
49.24[Cb]
44.22[Cd]
45.96[Bc]
43.28[Ce]
40.38[Cf]
36.45[Cg]
34.85[Bh]
33.44[Bi]
32.24[Cj]
32.32[Cj]
32.45[Cj]
33.64[Bi]
0.308
KP5
49.52[Ca]
48.12[Db]
42.19[De]
45.28[Bc]
43.45[Cd]
39.53[Df]
35.46[Dg]
34.32[Bh]
33.36[Bi]
32.27[Cjk]
32.65[Bij]
32.80[Cij]
31.60[Cjk]
0.267
SEM
0.469
0.355
0.172
0.270
0.213
0.142
0.143
0.204
0.316
0.147
0.288
0.204
0.194
a*
CON
5.49[Dg]
11.23[Dab]
11.65[Cab]
11.53[Dab]
11.62[Dab]
11.88[Da]
11.10[Dbc]
10.60[Db]
9.79[Cc]
8.61[De]
6.51[Cf]
4.85[Dh]
4.83[Dh]
0.206
KP1
7.87[Cg]
12.83[Cc]
13.00[Bc]
13.57[Cb]
13.82[Cab]
14.27[Ca]
12.80[Cc]
12.06[Cd]
11.52[Ae]
9.63[Cf]
7.04[Bh]
6.56[Ci]
6.47[Ci]
0.163
KP3
10.40[Bfg]
15.47[Bb]
15.47[Ab]
15.76[Bab]
15.87[Ba]
15.41[Bb]
14.42[Bc]
12.95[Bd]
10.84[Be]
10.59[Bef]
10.37[Afg]
10.18[Bg]
9.58[Bh]
0.115
KP5
13.05[Af]
15.97[Ac]
15.66[Ac]
16.67[Aab]
16.92[Aa]
16.47[Ab]
15.09[Ad]
13.60[Ae]
11.85[Ag]
11.50[Ag]
10.66[Ah]
10.61[Ah]
10.94[Ah]
0.130
SEM
0.155
0.138
0.173
0.120
0.065
0.259
0.173
0.117
0.195
0.162
0.171
0.131
0.097
b*
CON
14.51[Da]
13.45[Db]
12.40[Cc]
12.23[Dc]
11.19[Dd]
11.15[Dd]
10.02[De]
9.64[De]
8.64[Df]
8.03[Cg]
7.91[Cg]
7.90[Cg]
7.88[Cg]
0.182
KP1
22.32[Ca]
21.10[Cb]
18.46[Bc]
17.70[Cd]
17.31[Cd]
16.60[Ce]
13.75[Cf]
13.00[Cg]
12.60[Cg]
11.39[Bh]
11.02[Bhi]
10.53[Bi]
10.68[Bi]
0.211
KP3
27.14[Ba]
25.46[Bb]
22.56[Ac]
21.72[Bd]
20.65[Be]
19.22[Bf]
16.22[Bg]
15.44[Bh]
12.11[Bj]
12.04[Bj]
13.04[Ai]
13.27[Ai]
12.95[Ai]
0.211
KP5
30.55[Aa]
26.81[Ab]
23.06[Ade]
25.18[Ac]
23.65[Ad]
22.72[Ae]
17.33[Af]
16.29[Ag]
15.32[Ah]
13.47[Ai]
13.08[Ai]
13.45[Ai]
13.35[Ai]
0.238
SEM
0.329
0.125
0.195
0.249
0.219
0.143
0.225
0.162
0.133
0.245
0.174
0.254
0.198
A–D Means within same column with different
superscript letters differ significantly at p<0.05.
a–k Means within same row with different
superscript letters differ significantly at p<0.05.
1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
A–D Means within same column with different
superscript letters differ significantly at p<0.05.a–k Means within same row with different
superscript letters differ significantly at p<0.05.1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.The sensory properties of all pork salamis were presented in Table 6. The color scores of all sausages
significantly decreased during the aging period and were 6.42–7.57 at day
7 and 5.00–6.57 at day 56. The flavor scores of all pork salamis remained
until day 42, however, significantly decreased at day 49 and 56, and were the
lowest at the end of the aging period, but there was no significant difference
among treatments. Lee et al. (2008)
reported that taste and flavor increased with the levels of KP. The acidity
scores of all pork salamis increased throughout the aging period and were higher
in pork salamis with KP than in control, which we attribute to the significantly
low pH values of all pork salamis during the aging periods. Overall
acceptability of pork salami of KP3 on day 42, 49, and 56 was higher than that
of control. Judging by these results, the KP has improved scores of color,
appearance, and overall acceptability of salami in comparison with those of
control.
Table 6
Sensory evaluation of pork salami added with different concentrations
of kimchi powder
Items
Treatment[1)]
Days
7
14
21
28
35
42
49
56
SEM
Color
CON
6.43[Ba]
6.57[Ba]
6.29[Ba]
6.14[Ba]
6.00[Ba]
5.86[Bab]
5.14[Cbc]
5.00[Bc]
0.286
KP1
7.43[Aa]
7.29[Aa]
7.14[Aab]
7.07[Aab]
7.00[Aab]
6.57[ABbc]
6.00[Bcd]
5.86[Ad]
0.210
KP3
7.57[Aa]
7.57[Aa]
7.43[Aab]
7.36[Aab]
7.00[Aabc]
6.71[Abc]
6.71[Abc]
6.29[Ac]
0.260
KP5
7.29[Aab]
7.29[Aab]
7.43[Aa]
7.14[Aab]
7.00[Aab]
6.86[Aab]
6.86[Aab]
6.57[Ab]
0.224
SEM
0.226
0.222
0.264
0.177
0.289
0.254
0.233
0.289
Appearance
CON
6.57[Ba]
6.71[Aa]
6.71[Ba]
6.71[Ba]
6.43[Aab]
6.14[Aabc]
5.86[Bbc]
5.71[Bc]
0.224
KP1
7.00[Aa]
7.00[Aa]
7.00[ABa]
7.00[ABa]
6.86[Aa]
6.29[Ab]
6.00[ABb]
6.00[ABb]
0.137
KP3
7.14[Aab]
7.29[Aa]
7.29[Aa]
7.29[Aa]
6.71[Aab]
6.57[Ab]
6.57[Ab]
6.57[Ab]
0.187
KP5
7.14[Aa]
7.14[Aa]
7.14[ABa]
7.14[ABa]
6.57[Aab]
6.43[Ab]
6.43[ABb]
6.29[ABb]
0.218
SEM
0.143
0.184
0.149
0.149
0.184
0.240
0.222
0.251
Odor
CON
6.14[Ca]
6.14[ABa]
6.00[Aa]
5.71[Aa]
5.71[Aa]
5.43[Aa]
5.29[Aa]
5.29[Aa]
0.262
KP1
6.57[BCa]
6.43[Aa]
6.29[Aab]
6.14[Aab]
6.14[Aab]
6.00[Aab]
5.43[Ab]
6.00[Aab]
0.300
KP3
6.93[ABa]
5.71[ABab]
6.14[Aab]
6.14[Aab]
6.00[Aab]
5.86[Aab]
6.00[Aab]
5.57[Ab]
0.412
KP5
7.36[Aa]
5.29[Bb]
6.14[Aab]
6.14[Aab]
6.14[Aab]
6.57[Aab]
6.14[Aab]
5.57[Ab]
0.421
SEM
0.206
0.322
0.300
0.289
0.258
0.380
0.378
0.582
Flavor
CON
6.57[Aa]
6.57[Aa]
6.43[Aab]
6.14[Aabc]
6.00[Aabc]
6.00[Aabc]
5.86[Bc]
5.57[Ac]
0.193
KP1
6.71[Aa]
6.71[Aa]
6.57[Aa]
6.57[Aa]
6.57[Aa]
6.43[Aa]
6.29[ABa]
6.29[Aa]
0.222
KP3
6.86[Aa]
6.57[Aa]
6.57[Aa]
6.43[Aa]
6.57[Aa]
6.43[Aa]
6.57[Aa]
6.43[Aa]
0.237
KP5
6.86[Aa]
6.71[Aa]
6.43[Aa]
6.57[Aa]
6.43[Aa]
6.57[Aa]
6.43[ABa]
6.43[Aa]
0.259
SEM
0.202
0.247
0.202
0.218
0.206
0.233
0.214
0.295
Acidity
CON
4.57[Cc]
5.14[Cb]
5.86[Cab]
6.14[Ba]
6.00[Cab]
5.86[Cab]
5.43[Cabc]
5.29[Babc]
0.300
KP1
5.29[BCb]
5.71[Cab]
6.43[BCa]
6.43[Ba]
6.43[BCa]
6.29[BCa]
6.07[BCab]
5.57[ABab]
0.264
KP3
6.29[ABa]
6.71[Ba]
6.71[Ba]
6.86[ABa]
6.79[Ba]
6.71[Ba]
6.57[Ba]
6.14[ABa]
0.262
KP5
7.29[Aa]
7.57[Aa]
7.57[Aa]
7.36[Aa]
7.57[Aa]
7.43[Aa]
7.29[Aa]
6.86[Aa]
0.293
SEM
0.362
0.210
0.240
0.241
0.209
0.237
0.232
0.429
Preference
CON
6.57[Aa]
6.14[Aa]
6.00[Aa]
5.86[Ba]
6.00[Ba]
5.86[Ba]
5.86[Aa]
5.71[Aa]
0.270
KP1
6.43[Aa]
6.57[Aa]
6.57[Aa]
6.57[ABa]
6.43[ABa]
6.43[Aa]
6.29[Aa]
6.29[Aa]
0.212
KP3
6.57[Aa]
6.71[Aa]
6.71[Aa]
6.86[Aa]
6.79[Aa]
6.71[Aa]
6.57[Aa]
6.57[Aa]
0.257
KP5
6.71[Aa]
6.57[Aa]
6.43[Aa]
6.50[ABa]
6.43[ABa]
6.57[Aa]
6.43[Aa]
6.29[Aa]
0.298
SEM
0.274
0.306
0.254
0.243
0.236
0.184
0.264
0.309
Texture
CON
6.57[Aa]
6.14[Aab]
6.00[Aab]
6.00[Aab]
6.00[Aab]
5.86[Aab]
5.29[Bbc]
4.86[Ac]
0.287
KP1
6.57[Aa]
6.29[Aa]
6.14[Aa]
6.14[Aa]
6.00[Aab]
5.86[Aab]
5.86[ABab]
5.29[Ab]
0.256
KP3
6.57[Aa]
6.43[Aa]
6.43[Aa]
6.50[Aa]
6.43[Aa]
6.43[Aa]
6.14[Aab]
5.71[Ab]
0.221
KP5
6.57[Aa]
6.14[Aa]
6.43[Aa]
6.14[Aa]
6.14[Aa]
6.29[Aa]
5.71[ABa]
5.71[Aa]
0.269
SEM
0.202
0.202
0.222
0.301
0.274
0.277
0.198
0.355
Overall acceptability
CON
6.57[Aa]
6.21[Ba]
6.29[Ba]
6.14[Ba]
6.29[Aa]
6.14[Ba]
5.43[Bb]
5.29[Cb]
0.221
KP1
6.93[Aa]
7.00[Aa]
7.07[Aa]
6.57[ABab]
6.57[Aab]
6.14[Bb]
6.14[ABb]
6.07[Bb]
0.171
KP3
6.86[Aa]
6.57[ABa]
6.57[ABa]
6.86[Aa]
6.86[Aa]
7.00[Aa]
6.93[Aa]
7.00[Aa]
0.206
KP5
6.57[Aa]
6.07[Ba]
6.21[Ba]
6.21[Ba]
6.29[Aa]
6.93[Aa]
6.71[Aa]
6.43[AB]
0.311
SEM
0.197
0.202
0.247
0.195
0.210
0.243
0.291
0.260
A–C Means within same column with different
superscript letters differ significantly at p<0.05.
a–d Means within same row with different
superscript letters differ significantly at p<0.05.
1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
A–C Means within same column with different
superscript letters differ significantly at p<0.05.a–d Means within same row with different
superscript letters differ significantly at p<0.05.1) Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with
3% kimchi powder; KP5, pork salami added with 5% kimchi powder.
Microbiological characteristics of pork salami with KP
The LAB and total microorganism of pork salami with KP and the control are
depicted in Fig. 2. The initial LAB counts
of the control and the pork salami with KP ranged from 5.91 to 6.57 Log CFU/g.
The LAB counts of the control were higher than that of pork salami with KP at
day 1. After that, LAB counts were significantly higher in pork salami with KP
than in control during aging. The LAB counts of pork salami with KP attained
maximum levels (8.05–8.31 Log CFU/g) at day 2. Park and Lee (2012) found that the inoculated numbers of
LAB achieved by the addition of KP were higher than those of the control. After
1–2 days of fermentation, maximum numbers of LAB were reached. In
addition, Chouliara et al. (2006) reported
significant growth of LAB within the first four days of fermentation, reflected
in the increase of total viable counts (TVC). The fast growth of LAB is critical
for the quality and safety of the fermented sausage, because early growth of
these bacteria can prevent the growth of deteriorating and pathogenic bacteria
(Campagnol et al., 2011). At day 28,
the LAB counts of the control were 7.71 Log CFU/g, and the counts of pork salami
in KP1, KP3, and KP5 were 7.89, 7.97, and 8.02 Log CFU/g, respectively.
Thereafter, all LAB counts of pork salamis with KP decreased until the end of
the aging period. These results revealed that LAB counts of pork salamis
increased as concentration of KP was increased. The most important change during
fermentation is the conversion of sugars to lactic acid, so there is a
significant correlation between pH and LAB count. The microflora of sausage
during fermentation and aging changes as a result of the combined effects of
decreasing the Aw due to drying, lowering the pH, and increasing the brine
content, resulting in high numbers of LAB (Muguerza et al, 2002; Palumbo et
al., 1976).
Fig. 2
Number of lactic acid bacteria and total microorganisms of pork
salami added with kimchi powder.
A–C Values with different letters among treatments
differ significantly at p<0.05. a–f Values with
different letters during ageing differ significantly at p<0.05.
Con, pork salami added with commercial starter; KP1, pork salami added
with 1% kimchi powder; KP3, pork salami added with 3% kimchi powder;
KP5, pork salami added with 5% kimchi powder.
Number of lactic acid bacteria and total microorganisms of pork
salami added with kimchi powder.
A–C Values with different letters among treatments
differ significantly at p<0.05. a–f Values with
different letters during ageing differ significantly at p<0.05.
Con, pork salami added with commercial starter; KP1, pork salami added
with 1% kimchi powder; KP3, pork salami added with 3% kimchi powder;
KP5, pork salami added with 5% kimchi powder.The total microorganisms of all pork salamis increased by day 28, and the numbers
were maintained until the end of aging period. The initial numbers of total
microorganisms were higher in the control (6.31 Log CFU/g) than in KPs
(5.49–6.01 Log CFU/g). After day 2, the total microorganism counts of KPs
increased, and reached maximum levels (7.56–7.67 Log CFU/g) between day
21 to day 28 and decreased. These results indicate that total microorganism
counts are similar to the LAB counts. Kang et
al. (2012) reported that total bacteria counts of kimchi-fermented
sausages with sodium nitrite and green tea extract were similar to LAB counts
during aging periods.We determined E. coli and coliforms, while these were not
detected in the pork salami samples, from the initial phase to the end of the
aging period (data not shown). We assumed that the LAB may have inhibited growth
of these spoilage and pathogenic bacteria (Ahmad
and Srivastava, 2007). The main LAB species of kimchi is
Lactobacillus plantarum. Leuconostoc
mesenteroides, and the species of L. curvatus,
L. plantarum, and L. sakei are established
in kimchi, and have been described as the dominant lactobacilli in fermenting
sausages (Lee et al., 2006; Morishita and Shiromizu, 1986).The sequence analysis of 16S rRNA gene has been used to identify the community of
microorganisms that exist in various environments (Lee et al., 2001). The 16S rRNA gene sequence can classify
microorganisms to the genus level, and variable regions of specific sequence to
the specific species (Han et al., 1998).
The size of the PCR products was about 300 base pairs in all pork salamis. The
changes in taxa of 16S rRNA genes of LAB in all pork salamis are shown in Fig. 3. The number of
Lactobacillus in pork salamis with KP (Fig. 3a) was significantly higher than in the control by day
14. After that, there was no significant difference between treatments from day
21 to the end of the aging period. One study demonstrated that fermented lamb
sausage inoculated with the probiotic L. plantarum has a soft
texture and enhanced quality (Arief et al.,
2014). As mentioned before, pork salamis with KP also showed low
hardness, this may due to the probiotic Lactobacilllus. The
numbers of Pediococcus (Fig.
3b) and Staphylococcus (Fig. 3c) were significantly higher in the control than in
pork salamis with KP, because the starter culture consists of 4 microbes such as
Staphylococcus xylosus, Staphylococcus
carnosus, Pediococcus acidilactici, and
Pediococcus pentosaceus. Although KP contains a low level
of Pediococcus spp. (7.05%), as concentration of KP in pork
salami was increased, the numbers of Pediococcus increased
significantly. Pork salamis may provide the perfect environment for
Pediococcus fermentation. In addition, the numbers of
Leuconostoc (Fig. 3d)
in pork salamis with KP increased at day 7, and the value was significantly
higher than that of control. This result reflects the results of LAB counts in
pork salamis with KP, because LAB counts increased from the initial phase to day
7. The counts of Leuconostoc in pork salamis with 1% KP and KP
itself were the highest, showing 40.45% and 22.53%, respectively (Fig. 3e). Pork salamis in KP 1 had higher
levels of Leuconostoc compared to KP3 and KP5. In contrast, the
counts of Leuconostoc in the control was low during the aging
periods, due to its absence from the commercial starter.
Leuconostoc spp. are regarded as important for the
development of flavor and specific taste in fermented sausage, since they
produce other metabolites such as lactic acid, acetic acid, dextran,
acetaldehyde, diacetyl, and ethanol (Kim and
Lee, 2013; Lee et al.,
2006).
Fig. 3
Changes in taxa of genus Lactobacillus (a),
Pediococcus (b), Staphylococcus
(c), Leuconostoc (d) of kimchi powder itself (e) and
pork salami added with different concentrations of kimchi
powder.
A–D Values of bar with different letters among
treatments differ significantly at p<0.05. a–d
Values of bar with different letters during ageing differ significantly
at p<0.05. Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with 3%
kimchi powder; KP5, pork salami added with 5% kimchi powder.
Changes in taxa of genus Lactobacillus (a),
Pediococcus (b), Staphylococcus
(c), Leuconostoc (d) of kimchi powder itself (e) and
pork salami added with different concentrations of kimchi
powder.
A–D Values of bar with different letters among
treatments differ significantly at p<0.05. a–d
Values of bar with different letters during ageing differ significantly
at p<0.05. Con, pork salami added with commercial starter; KP1,
pork salami added with 1% kimchi powder; KP3, pork salami added with 3%
kimchi powder; KP5, pork salami added with 5% kimchi powder.
Conclusions
This study was performed to investigate the properties of fermented pork salamis with
KP, and to characterize their diversity of LAB. In this study, we found that
addition of KP to pork salami improves the quality characteristics and enhances
texture, flavor, and LAB counts with increasing concentrations of KP. Addition of 1%
KP to pork salami is most effective due to the resulting high numbers of
Leuconostoc bacteria and low TBARS value. Therefore, the KP may
serves as a potential natural compounds for fermented meat products like
Metzgerei.
Authors: I Chouliara; J Samelis; A Kakouri; A Badeka; I N Savvaidis; K Riganakos; M G Kontominas Journal: Meat Sci Date: 2006-04-18 Impact factor: 5.209