• 한국식품저장유통학회지
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• 제10권3호
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• pp.345-359
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• 2003

김치 제조시 녹차 물추출물의 첨가방법이 발효특성과 관능적 품질에 미치는 영향을 조사하기 위하여 배추의 절임시 1% 녹차 물 추출물을 함유하는 10%소금물로 24시간 절임한 후 담근 김치(SG), 10% 소금물로 24시간 절인 후 1% 녹차 추출물에 30분간 담근 후 담근 김치(DG) 및 1% 녹차 물 추출물과 양념을 혼합하여 담근 김치(MS)를 1$0^{\circ}C$에서 숙성키면서 발효 특성과 관능적 품질을 조사하였다. 김치의 숙성 중 pH는 전반적으로 녹차처리구가 대조구에 비하여 높아 녹차처리로 숙성이 지연되었으나 녹차 처리구 상호간의 뚜렷한 차이는 보이지 않았다. SB-김치의 총균수는 6.27-9.37logCFU/mL 녹차 첨가한 SG-, BG-, MS-김치의 5.17-9.20logCFU/mL 높았으며, 적숙기의 총균수에 대한 젓산균의 비율은 SB-김치가 SG-, DG-, MS-김치보다 높았다. 숙성 5일째 김치의 총 polyphenol 함량은 DG 52.75 mg%, MS 47.71 mg%, SG 44.89 mg%, SB 30.70 mg%로 DG에서 가장 높은 함량을 나타내었다. 숙성 5일째 김치의 사각사각한 맛은 SG 및 DG에서 각각 4.03 및 4.01점으로 대조구보다 높은 값을 보였으며 비린 맛과 매운 맛은 녹차 처리구에서 전반적으로 낮았다. 종합적인 맛은 DG 및 MS가 높은 평가치를 나타내었다.

• Journal of Dairy Science and Biotechnology
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• 제33권1호
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• pp.83-91
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• 2015

Yogurt is a product of the acidic fermentation of milk, which affects the survival of lactic acid bacteria (LAB). The aim of this present study was to examine the survival and acid stress response of Lactobacillus rhamnosus GG to low pH environment. The survival of LAB in commercial yogurt was measured during long-term storage. The enumeration of viable cells of LAB was determined at 15-day intervals over 52-weeks at $5^{\circ}C$. L. acidophilus, L. casei, and Bifidobacterium spp. showed low viability. However, L. rhamnosus GG exhibited excellent survival throughout the refrigerated storage period. At the end of 52-weeks, L. rhamnosus GG survived 7.0 log10 CFU/mL. $F_0F_1$ ATPase activity in L. rhamnosus GG at pH 4.5 was also evaluated. The ATPase activities of the membranes were higher when exposed at pH 4.5 for 24 h. The survival of L. rhamnosus GG was attributable to the induction in $F_0F_1$ ATPase activity. In addition, the mRNA expression levels of acid stress-inducible genes at low pH were investigated by qRT-PCR. clpC and clpE genes were up-regulated after 1 h, and atpA and dnaK genes were up-regulated after 24 h of incubation at pH 4.5. These genes could enhance the survival of L. rhamnosus GG in the acidic condition. Thus, the modulation of the enzymes or genes to assist the viability of LAB in the low pH environment is thought to be important.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.464-468
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• 2015

The production of gamma-aminobutyric acid (GABA) using GABA-producing lactic acid bacteria (LAB) has been considered to be an attractive strategy. However, some LAB may produce biogenic amines (BA), which may be of concern from the safety viewpoint. The aim of the present study was to characterize the production of GABA and BA in the soybean pastes fermented by Aspergillus oryzae (A. oryzae) FMB S46471 and GABA-producing Lactobacillus brevis (L. brevis) GABA 100. After a ripening period of 90 days, the levels of BA (putrescine, cadaverine, histamine, and tyramine) and GABA in the fermented soybean were assessed by highperformance liquid chromatography. The soybean pastes fermented by A. oryzae and L. brevis showed a range of 7,130-11,592 mg/kg for GABA, 178-305 mg/kg for tyramine, 139-163 mg/kg for putrescine, 7.4-10.8 mg/kg for histamine, and 7.1-7.9 mg/kg for cadaverine, whereas the soybean pastes fermented by A. oryzae only showed a range of 30-1,671 mg/kg for GABA, 0.8-189 mg/kg for tyramine, 1.3-85 mg/kg for putrescine, up to 3.6 mg/kg for histamine, and 0.2-2.4 mg/kg for cadaverine. The results showed that the production of GABA was accompanied by the increase in the production of BA, even though the production levels of histamine and cadaverine were very low. This is the first study to simultaneously characterize the production of BA and GABA in GABA-enriched fermented soybean pastes, and warrants further study to minimize the production of BA while optimizing the production of GABA.

• Journal of Microbiology
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• 제39권1호
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• pp.11-16
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• 2001

Tentative identification of Leuconostoc lactis IH23 isolated from kimchi (a fermented vegetable product) has been described previously with 16S rDNA sequencing (Choi, 1., M. Sc. Thesis Inha Univ.1999). This strain produced the slime identified as dextran based on IR, $\^$13/C- and $^1$H-NMR spectroscopic results. Further study proved that the isolate IH23 belongs to a homogeneous genetic group with L. lactis DSM 20202$\^$T/ and L. argentinum DSM 8581$\^$T/. The results showed DNA-DNA homology of 99-100%, 16S rDNA gene sequence similarity (97.7% ), and a phylogenetic relationship although L. argentinum DSM 8581$\^$T/ had lower homology (80-91%). These data indicate that L. argentinum DSM 8581$\^$T/ and the isolate IH23 belong to an identical species with L. lactis DSM 20202$\^$T/at the genetic level, although in carbohydrate fermentation, the isolate IH23 was mast closely related to L. argentinum DSM 8581$\^$T/ and quite different from L. lactis DSM 20202$\^$T/. Here we first report the isolation of consistent phenotypic variation in Leuconostoc lactis. We also emphasize that the nomenclature of subspecies needs to be differentiated into the three strains mentioned above in Leuconostoc lactis.

• 한국미생물·생명공학회지
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• 제20권1호
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• pp.46-52
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• 1992

농축유청으로부터 유청음료 제조를 위한 최적조건을 조사하기 위해 역삼투장치(reverse osmosis system)를 사용하여 치즈유청 속의 유당을 농축한 수 $\beta$-D-glactosidase로 가수분해시켜 그 분해정도를 HPLC(high performance liquid chromatography)로 측정하였다. 유당의 가수분해 정도는 농축적 유청, 2배 농축 유청과 3배 농축 유청 순으로 가수분해되었고 일정량의 효소첨가에 의해 농축된 염이 $\beta$-D-Galactosidase에 대한 약간의 저해작용을 일으켰다.

• 한국축산식품학회지
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• 제30권4호
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• pp.649-654
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• 2010

In order to develop new functional yogurts using mulberries and mulberry leaves, which were cultivated in Hwasun-gun, Jeonnam Province, Korea, the nutritional compositions, fermentation conditions, sensory properties, and storage stabilities of the yogurts were analyzed. The mulberry powder yogurt contained 87.96% moisture, 3.21% carbohydrate, 4.52% protein, 3.63% lipid, and 0.68% ash, and the mulberry leaf yogurt contained 86.36% moisture, 4.13% carbohydrate, 4.87% protein, 3.79% lipid, and 0.85% ash. A yogurt base was fermented for 13 h with 0.01% ABT-5 starter inoculum at $40^{\circ}C$. To prepare the mulberry jam and mulberry leaf yogurts, a variety of mulberry jam and mulberry leaf samples were added to the yogurt base. The sensory evaluation results of the yogurts containing the mulberry jam and mulberry leaves indicated that a product made with 15% mulberry jam was more strongly preferred than other samples. When the mulberry jam and mulberry leaf yogurts were stored at $4^{\circ}C$ for 15 d, there were no significant changes in pH, titratable acidity, or viable cell numbers of lactic acid bacteria and Bifidobacterium bifidum.

• Preventive Nutrition and Food Science
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• 제11권4호
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• pp.285-288
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• 2006

The anti-adipogenic effect of dongchimi nano juice prepared using a nano-filtering process was investigated by measuring leptin and glycerol levels and the expression of a peroxisome proliferator-activated $receptor-\gamma\;(PPAR\gamma)$ gene as indicators of lipid accumulation or lipolysis. Red pepper powder, seeds of red pepper, garlic, and ginger were added in the preparation of dongchimi. Dongchimi was fermented to reach the optimal fermentation period, followed by nano-filtration in the range of $0.0005\sim0.1\;{\mu}m$. The lactic acid bacteria of dongchimi nano juice were removed completely by a nano-filtering process. Treatment of dongchimi nano juice induced glycerol release in the 3T3-L1 adipocytes and decreased the mRNA expression level of $PPAR\gamma$. These results suggested that dongchimi nano juice may enhance lipolysis and modulate adipogenesis in 3T3-L1 cells.

• Journal of Microbiology and Biotechnology
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• 제12권5호
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• pp.801-806
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• 2002

A multiplex competitive polymerase chain reaction (PCR) method was developed for the rapid identification and quantification of Leuconostoc mesnteroides and Lactobacillus plantarum populations which are the key microorganisms in kimchi fermentation. The strain-specific primers were designed to selectively amplify the target genes encoding 165 rRNA of L. plantarum and dextransucrase of L. mesenteroides. There was a linear relationship between the band intensity of PCR products and the number of colony forming units of each model organism. The PCR quantification method was compared with a traditional plate-counting method f3r the enumeration of the two lactic acid bacteria in a mixed suspension culture and also applied to a real food system, namely, watery kimchi. The population dynamics of the two model organisms in the mixed culture were reliably predictable by the competitive PCR analysis.

• Food Science and Biotechnology
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• 제16권2호
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• pp.193-197
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• 2007

In order to investigate the effects of Pichia farinosa SKM -1, Pichia anomala SKM-T, Galactomyces geotrichum SJM-59, and Saccharomyces cerevisiae on extending the shelf life of kkakdugi, 4 kinds of lyophilized yeasts adding kkakdugis were prepared and stored at $4^{\circ}C$ for 30 days. Except S. cerevisiae adding group, 3 kinds of yeast adding groups were maintained their desirable levels (ca. pH 4.2 and 0.6% acidity) during the fermentation. The hardness of yeast adding groups was higher than those of control during the experiments. The number of yeast and the ratio of lactic acid against to total bacteria in P. farinosa SKM-1, P. anomala SKM-T, and G geotrichum SJM-59 adding groups were lower than that of control and/or S. cerevisiae adding group. Based on acidity, kkakdugi made with P. farinosa SKM-1, P. anomala SKM-T, and G geotrichum SJM-59 remained edible about 10 days longer than the control product.

• 유기물자원화
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• 제11권1호
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• pp.101-101
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• 2003

본 연구는 남은 음식물을 유산균을 이용하여 발효 사료화 하기 위해 실시하였다. 발효를 촉진시키기 위한 균주로는 Lactobacillus acidophilus를 사용하였고 최적의 발효조건을 갖는 공기 주입량을 알아보기 위해 시료의 발효 조건을 각각 달리 하였다. 시료는 교반하지 않고 공기주입 또한 없는 혐기적 조건의 것과 50rpm의 속도로 교반하면서 0.25v.v.m의 공기를 주입한군, 70rpm의 속도로 교반하면서 0.5v.v.m의 공기를 주입한 군으로 나누었다. 시료는 모두 $37^{\circ}C$로 유지하면서 48시간 발효 시키며 12시간 단위로 시료를 채취하였다. p.H와 유기산함량, 환원당함량과 유산균수를 측정하여 남은 음식물을 발효시키기 위한 최적의 공기 주입량을 알아보았다. 실험결과 50rpm 0.25v.v.m에서 가장 낮은 p.H를 보여주었고 유기산 함량과 환원당 함량은 70rpm 0.5v.v.m에서 가장 높은 함량을 보였다. 유산균은 50rpm 0.25v.v.m에서 가장 많은 증식되었음을 보여주어 적절한 공기의 주입이 남은 음식물의 발효를 촉진하는 것으로 보여진다.