• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.335-342
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• 2015

We conducted a study on mukeun (long-term fermented) kimchi ripened over one year in an attempt to develop an alternative salt and improve the quality of low-salt kimchi. However, few studies have focused on mukeun kimchi that has been fermented for a short time in different salinity conditions. Therefore, the aim of this study was to investigate the physicochemical characteristics that occur during the fermentation of mukeun kimchi samples produced with different conditions of salinity and fermentation temperature. Kimchi samples were produced at 3 different salinity levels: 1.6%, 2.4%, and 3.2%. Previous studies revealed that the optimum fermentation time at pH 4.1 was 128 hours at $18^{\circ}C$ and 417 hours at $12^{\circ}C$; furthermore, the samples were stored for 12 weeks under the condition of $-1^{\circ}C$ after fermentation. Total cell increased on week 0 of storage and decreased according to the storage period. Total cell was the highest at 3.2% salinity and had a high value at $18^{\circ}C$ temperature during the storage period. Based on the physiochemical results, mukeun kimchi at a salinity of 3.2% can be fermented for a short time, and low-salt kimchi at a salinity of 1.6% and fermented at $18^{\circ}C$, is similar to mukeun kimchi at 2.4% salinity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.12
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• pp.1771-1777
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• 2012

This study was conducted to investigate the physicochemical characteristics of seafood added kimchi (SAK) during fermentation and its sensory properties. Korean cabbage kimchi (KCK) and four different SAKs were prepared and stored at $5^{\circ}C$ for eight weeks. The SAKs contained pre-treated octopus, squid, abalone, and webfoot octopus added at 12% (w/w) to the brined Korean cabbage. The fermentation patterns of SAKs were similar to those of KCK, indicating that the SAKs followed a typical fermentation process. Comparison of the physicochemical characteristics of SAKs with KCK revealed that the pH and acidity of SAKs was higher. The maximum concentrations of Lactobacillus spp. and Leuconostoc spp. for SAKs ranged from 8.31~8.85 and 7.60~8.14 log CFU/mL, respectively, which were higher than those for KCK. Therefore, the production of organic acids by microorganisms was greater in SAKs, which explained the higher acidities of the SAKs. Nitrogenous compounds hydrolyzed during fermentation, as well as reducing sugars and other nutritious compounds in SAKs might provide a good medium for lactic acid bacterial growth. Sensory evaluation was carried out using optimally ripened kimchi (pH $4.3{\pm}0.1$, acidity $0.7{\pm}0.1$), and the scores for sour taste, sour smell, and carbonated taste were significantly lower for SAKs than KCK. In the preference test, texture and overall acceptability were significantly higher for SAKs than KCK. Significant differences were not observed among SAKs upon subjective and preference evaluations. In conclusion, the fermentation patterns of SAKs were normal, regardless of seafood sources, and their sensory characteristics were comparable to or superior than those of KCK due to free amino acids, nitrogenous compounds produced during the fermentation, and reducing sugar present in the seafood.

• Microbiology and Biotechnology Letters
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• v.41 no.1
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• pp.119-127
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• 2013

Twenty-three strains of Leuconostoc species and 45 strains of Weissella species inhibiting the growth of Lactobacillus sakei, one of the most populous lactic acid bacteria in over-ripened kimchi, were isolated from kimchi in our previous study. Among these hetero-fermentative 68 strains, Leuconostoc mesenteroides CK0128, Weissella cibaria CK0633, and W. cibaria KK0797 exhibited a relatively high survival rate in MRS medium, which was adjusted to pH 4.3 using an acid mixture consisting of acetic and lactic acids, and produced a large amount of exopolysaccharides. The culture supernatants of 3 strains were fractionated by a molecular weight cutter and lyophilized. The fractions with a molecular weight smaller than 3,000 Da showed antagonistic activity against Staphylococcus aureus and Lb. sakei. The anti-bacterial substances were very stable to heat treatments ($121^{\circ}C$, 15 min) and active at acidic conditions below pH 5. ${\alpha}$-Amylase, lipase, and proteolytic enzymes (proteinase K and pepsin) did not affect their activities. These non-proteinaceous anti-bacterial substances inhibited the growth of several food pathogens.

• Food Science and Preservation
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• v.14 no.5
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• pp.526-530
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• 2007

The effects of kwamaegi (0, 6, 12 and 18%, all w/w) on the quality characteristics of Kimchi during fermentation at $10^{\circ}C$ were investigated. The mixtures are denoted KK. The late of decrease in pH during KK fermentation was lower than that of control. The number of total microbes (T) in Kimchi controls fermented for 14 days did not differ, and were in the range of $8.64{\sim}8.68\;log\;CFU/g$, whereas the numbers of lactic acid bacteria (L) in KK were higher than in controls. The L/T(%) was 78.41 in control, 85.76 in 6% KK and $93.68{\sim}94.25%$ in the 16% or 18% KK samples. The hardness of tissue ($2.98{\sim}3.66{\times}10^7\;dyne/cm^2$) in KK fermented for 14 days was higher than that of control ($2.67{\times}10^7\;dyne/cm^2$). The content of alcohol-insoluble substances in KK juice (1.281.08 g/100 g) was lower than that of control (1.45 g/100 g). In sensory evaluation, the appearance and texture of KK were better than those of control. Although some fishy flavor was noted in KK, this did not affect acceptability. Sourness was less, whereas ripened taste and overall acceptability were higher in KK (especially 12% KK) compared to control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.6
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• pp.776-783
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• 2005

To develop functional kimchi which had anti-obesity effect, garcinia cambogia extract containing $51.46\%$ hydroxy citric acid (HCA) was used as a sub-ingredient of American preferred kimchi (APK). The APK added to garcinia cambogia extracts of 0.5$\%,\;1.0\%,\;1.5\%\;and\;2.0\%$ were prepared, and fermentation characteristics and anti-obesity effect of those kimchi were investigated. The pH of APK added to garcinia cambogia extracts (APKH) was low as the amount of garcinia cambogia extract increased at initial stage of fermentation but the pH of those kimchi showed similar values after optimum ripened stage. The number of Lactobacillus sp. and Leuconostoc sp. were small as the amount of garcinia cambogia extract increased while the period was delayed that the number of Lactobacillus sp. and Leuconostoc sp. attained to maximum. In Hunter's color values of APKH, lightness and redness decreased as the amount of garcinia cambogia extracts increased while yellowness increased. Sensory scores in overall acceptance, taste and texture of APKH evaluated by Americans as sensory panels were similar until the addition amount of garcinia cambogia extract was $1.5\%$, therefore the garcinia cambogia extract of $1.5\%$ was determined as tile amount adding to APK. The secretions of glycerol and leptin as a key signalling factor for anti-obesity effect were examined in APK and APKH added to garcinia cambogia extract of $1.5\%$. There were no significant differences in the glycerol secretion when adipocytes were treated with APK and APKH extracts. However, leptin secretion in the adipocytes treated with APKH extract was significantly decreased compared to that of control (p<0.05).

• Food Science and Preservation
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• v.19 no.5
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• pp.774-782
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• 2012

Baechu kimchi without cuttlefish (control), baechu kimchi with cuttlefish (CK), cuttlefish baechu kimchi with yogurt (CK+Y), and cuttlefish baechu kimchi with vitamin C (CK+VC) were prepared, and the fermentation characteristics of the prepared kimchi samples were investigated during 28 days of fermentation at $4^{\circ}C$. The levels of moisture, crude lipid, and crude ash did not differ much among the samples, but the crude protein levels of CK, CK+Y, and CK+VC were greater than that of the control. The pH values of CK+Y and CK+VC slowly decreased compared with those of the control and CK during fermentation. The acidity increased sharply until 21 days then gradually increased thereafter. The total microbial counts achieved maximum levels at 21 days, and the kimchi to which yogurt and vitamin C were added showed values lower than that of the control. The number of Leuconostoc sp. in CK+Y and CK+VC was higher than that in the control. In our sensory evaluations, cuttlefish kimchi with yogurt or vitamin C scored highest in terms of texture, sour taste, ripened taste, and overall acceptability.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1426-1432
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• 2000

The effects of raw anchovy, salted raw anchovy (20% salt+anchovy), 6- and 12-month fermented anchovy (20% salt added) on the N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)-induced mutagenicities were evaluated using Salmonella assay and the SOS chromotest. The methanol extracts from raw, salted and the fermented anchovy (FA) sample increased the revertants of Salmonella typhimurium TA100 at the level of $0.125{\sim}5\;mg/plate$ in Ames test. The salted raw anchovy extract induced the largest number of the revertants. All the FA extracts had comutagenic effect on the MNNG. Twelve-month FA juice exerted the lowest comutagenic activity among the FA samples. The comutagenicity of 12-month FA was due to the synergistic effect of salt and histidine which teem in FA. Thus the Ames test using histidine requiring mutant, S. typhimurium, is not appropriate to determine the mutagenicity of FA which is rich in histidine. In SOS chromotest using E coli, raw, salted and fermented anchovy extracts did not show any mutagenicity in the absence of MNNG. The raw and fermented anchovy samples blocked the SOS response of E. coli PQ37 induced by MNNG, while raw salted anchovy increased the SOS induction factor. Twelve-month FA juice showed higher antimutagenic effects than 6-month FA samples (both solid and liquid). The ripened (12-month) FA along with raw anchovy in the SOS chromotest exhibited antimutagenic activity.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.211-215
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• 2015

From the previous study, Enterococcus faecium SH01 was isolated from mukeunji, an over-ripened kimchi, and it produced bacteriocin SH01. Bacteriocin SH01 showed an inhibitory effect against Listeria monocytogenes ATCC 19111, a bacterial strain causing human listeriosis. Crude bacteriocin SH01 was purified by ammonium sulfate precipitation and its inhibitory activity at two concentrations (500 and 1,000 AU/g) against Listeria monocytogenes ATCC 19111 was investigated in ground beef at increasing temperatures (5, 10, 15, and 20℃) for 8 d. The number of Listeria monocytogenes ATCC 19111 significantly decreased (p<0.05) as the concentration of bacteriocin increased from 500 to 1,000 AU/g. Intrinsic crude protease activities in ground beef were examined and increased as the temperature increased. Experiments varying both the concentrations of added bacteriocin SH01 and temperature demonstrated a maximum inhibition (2.33 log reduction of bacteria) in samples containing 1,000 AU/g of bacteriocin SH01 incubated at 20℃. When the crude bacteriocin SH01 solution (1,280 AU/mL) was incubated with crude protease solutions at different temperatures, its activity decreased by only half (640 AU/mL), as assessed in an agar well diffusion assay. The finding that the antilisterial activity of bacteriocin SH01 increased with temperature can be explained by the fact that higher temperatures increase bacterial membrane fluidity, thereby promoting the cellular penetration of bacteriocin SH01 into L. monocytogenes. Bacteriocin SH01 may be an excellent candidate as a biopreservative for controlling L. monocytogenes growth in ground beef.

• Journal of Dairy Science and Biotechnology
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• v.30 no.2
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• pp.75-81
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• 2012

Molds cause severe cheese deterioration, even though some white and blue molds are used for the manufacture of Camembert and Blue cheese, respectively. The species of Geotrichum, Moniliella, Aspergillus, Penicillium, Mucor, Fusarium, Phoma, and Cladosporium are the main fungi that affect contamination during cheese ripening. Once deteriorated by fungal spoilage, cheese becomes toxic and inedible. Fungal deterioration of cheese decreases the nutritional value, flavor profiles, physicochemical and organoleptic properties, and increases toxicity and infectious disease. Fungal contamination during cheese ripening is highly damaging to cheese production in Korean farmstead milk processing companies. Therefore, these companies hesitate to develop natural and ripened cheese varieties. This article discusses the recent and ongoing developments in the removal techniques of fungal contamination during cheese ripening. There are 2 categories of antifungal agents: chemical and natural. Major chemical agents are preservatives (propionic acid, sodium propionate, and calcium propionate) and ethanol. Among the natural agents, grapefruit seed extract, phytoncide, essential oils, and garlic have been investigated as natural antifungal agents. Additionally, some studies have shown that antibiotics such as natamycin and Delvocid$^{(R)}$, have antifungal activities for cheese contaminated with fungi. Microbial resources such as probiotic lactic acid bacteria, Propionibacterium, lactic acid bacteria from Kimchi, and bacteriocin are well known as antifungal agents. In addition, ozonization treatment has been reported to inhibit the growth activity of cheese-contaminating fungi.

• Korean Journal of Microbiology
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• v.52 no.4
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• pp.471-481
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• 2016

The primary objective of this study was to investigate the effects of the bacteriocin-producing heterofermentative lactic acid bacteria (LAB) and acid-resistant yeast isolated from Mukeunji, a Korean ripened kimchi on shelf-life extension and quality improvement of sourdough. According to gene sequence analysis the heterofermentative LAB that showed the antimicrobial activity against bread-spoilage Bacillus strains were identified as Leuconostoc mesenteroides LAS112, Lactobacillus brevis LAS129, and L. mesenteroides subsp. dextranicum LAB137. In addition, the yeasts that were able to grow at acidic pH were identified as Pichia membranifaciens YS05, Pichia fermentans YS19, and Pichia anomala YS26. During sourdough fermentation the levels of acetic acid and bacteriocin produced by L. brevis LAS129 strain were higher than those of L. mesenteroides LAS112 and L. mesenteroides subsp. dextranicum LAS 137 strains, whereas LAS112 strain produced the highest levels of lactic acid. The maximum bacteriocin activity (640 AU/g) against Bacillus subtilis ATCC 35421 was obtained in sourdough fermented by mixed culture of L. brevis LAS129 and P. membranifaciens YS05 or P. anomala YS26. After 24 h of fermentation at $30^{\circ}C$, the viable cell counts of LAS129 ($10^9CFU/g$) in sourdough were higher than those of the YS05 or YS26 ($10^7CFU/g$). Meanwhile, the viable cells of bread-spoilage strain in sourdough fermented with these strains were significantly (P < 0.05) lower than the control group.