• Journal of Microbiology and Biotechnology
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• v.32 no.3
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• pp.341-347
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• 2022

In this study, the bacterial community of galchi-baechu kimchi was determined using culture-based and culture-independent techniques (next generation sequencing:NGS), and showed discrepancies between results. Weissella koreensis and Pediococcus inopinatus were the dominant species according to the NGS results, while Bacillus species and P. inopinatus were dominant in the culture-dependent analysis. To identify safe starter candidates, sixty-five Bacillus strains isolated from galchi-baechu kimchi using culture-dependent methods were evaluated for their antibiotic resistance, presence of toxin genes, and hemolytic activity. Strains were then assessed for salt tolerance and protease and lipase activity. As a result, four strains-B. safensis GN5_10, B. subtilis GN5_19, B. velezensis GN5_25, and B. velezensis GT8-were selected as safe starter candidates for use in fermented foods.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.636-648
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• 2020

This study investigated the effects of the addition levels of white kimchi powder and acerola juice powder, as natural sources of sodium nitrite and sodium ascorbate, on the quality of cooked ground pork products. Freeze-dried white kimchi powder was prepared and used after fermentation for 2 wk. Six treatments were included: control (100 ppm sodium nitrite and 500 ppm sodium ascorbate), treatment 1 (0.2% white kimchi powder, 0.02 % starter culture, and 0.1% acerola juice powder), treatment 2 (0.2% white kimchi powder, 0.02% starter culture, and 0.2% acerola juice powder), treatment 3 (0.4% white kimchi powder, 0.04% starter culture, and 0.1% acerola juice powder), treatment 4 (0.4% white kimchi powder, 0.04% starter culture, and 0.2% acerola juice powder), and treatment 5 (0.4% celery powder, 0.04% starter culture, and 0.2% acerola juice powder). The pH values were decreased (p<0.05) because of lower pH of acerola juice powder, resulting in lower cooking yields (p<0.05) in these treatments. CIE L* and CIE a* values of indirectly cured meat products were not different (p>0.05) from the sodium nitrite-added control. However, indirectly cured meat products showed lower (p<0.05) residual nitrite contents, but higher (p<0.05) nitrosyl hemochrome contents and cure efficiency than the control. Treatments 2 and 4 had higher (p<0.05) total pigment contents and lipid oxidation than the control. This study indicates that white kimchi powder coupled with acerola juice powder has substantial potential to substitute synthetic nitrite to naturally cured meat products, which could be favored by consumers seeking clean label products.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.512-526
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• 2020

Synthetic nitrite is considered an undesirable preservative for meat products; thus, controlling synthetic nitrite concentrations is important from the standpoint of food safety. We investigated 1,000 species of microorganisms from various kimchi preparations for their potential use as a starter culture for the production of nitrites. We used 16S rRNA gene sequence analysis to select a starter culture with excellent nitrite and nitric oxide productivity, which we subsequently identified as Staphylococcus hominis subspecies hominis WiKim0113. That starter culture was grown in NaCl (up to 9%; w/v) at 10℃-40℃; its optimum growth was observed at 30℃ at pH 4.0-10.0. It exhibited nonproteolytic activity and antibacterial activity against Clostridium perfringens, a bacterium that causes food poisoning symptoms. Analysis of Staphylococcus hominis subspecies hominis WiKim0113 with an API ZYM system did not reveal the presence of β-glucuronidase, and tests of the starter culture on 5% (v/v) sheep blood agar showed no hemolytic activity. Our results demonstrated the remarkable stability of coagulase-negative Staphylococcus hominis subspecies hominis WiKim0113, especially in strain negative for staphylococcal enterotoxins and sensitive to clinically relevant antibiotics. Moreover, Staphylococcus hominis subspecies hominis WiKim0113 exhibited a 45.5% conversion rate of nitrate to nitrite, with nitrate levels reduced to 25% after 36 h of culturing in the minimal medium supplemented with nitrate (200 ppm). The results clearly demonstrated the safety and utility of Staphylococcus hominis subspecies hominis WiKim0113, and therefore its suitability as a starter culture.

• Journal of Food Hygiene and Safety
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• v.30 no.1
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• pp.65-73
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• 2015

The purpose of this study is to evaluate quality characteristics of the Cheonggukjang produced using rice straw-derived Bacillus cereus free starter culture (RiBS1). The Cheonggukjang was prepared in 0.1 and 1.0% inoculum concentrations of starter culture and fermented from 12 hr to 72 hr at 40 and $50^{\circ}C$. Amino-nitrogen contents after 48 hr fermentation were 559.6~590.2 mg% and 393.8~494.0 mg% at 40 and $50^{\circ}C$, respectively. Sensory evaluation showed that the Cheonggukjang fermented using RiBS1 starter for 48 hr at $50^{\circ}C$ was better than the control. And we inspected on B. cereus and biogenic amine in the Cheonggukjang produced using RiBS1 starter. As a results, B. cereus was not detected and histamine and tyramine of biogenic amine were $5.53{\pm}0.13{\sim}39.96{\pm}0.62mg/kg$. This research results showed that rice straw-derived B. cereus free starter culture (RiBS1) will be produce the Cheonggukjang with good flavour and taste.

• Bulletin of Food Technology
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• v.10 no.1
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• pp.102-114
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• 1997

발효식품에서 분리한 젖산균인 Lactobacillus plantarum(NFS #6-6과 S #3)의 발효소시지에서 starter culture로의 이용가능성을 알아보기 위하여 상업용 혼합 starter culture인 SL(Staphylococcus carnosus+ Lactobacillus pentosus)을 비교구로하여 발효소시지를 제조하고 그 특성을 상호 비교하였다. 발효 및 숙성 중 변화에서 starter culture의 종류에 관계없이 최종 43~45%의 수분이 증발되었다. PH는 SL 처리구가 가장 낮은 4.3 수준이었으며 수분활성도 역시 0.88로 SL 처리구가 가장 낮았다. 색도에서 적색도는 SL 처리구보다 NFS #6-6과 S #3 처리구가 더 높았으며 텍스쳐, 지방산, 그리고 유리아미노산의 변화에서 starter culture에 따른 차이점은 없었다. 관능평가시 색깔에서는 NFS #6-6 처리구가 SL 처리구에 비하여 낮았으나 향기, 맛, 텍스쳐와 기호도에있어서는 SL과 비슷한 결과를 나타내었다. 유산균수는 발효 2일째 급격히 증가하는 추세($10^8 cfu/g이상)였으나 S #3과 NFS #6-6이 더욱 빠른 성장을 보였으며 Step. aureus는 모든 처리구에서 검출되지 않았다. 장내세균의 경우 SL 처리구에 비하여 우수하여 S #3 처리구는 3일째, NFS #6-6 처리구는 8일째부터 검출되지 않았으며 Listeria 역시 SL처리구보다 우수한 억제력을 나타내었다.

• Journal of Dairy Science and Biotechnology
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• v.36 no.3
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• pp.178-185
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• 2018

Kefir, which originates in the Caucasian mountains, is a cultured milk beverage produced by a combination of acidic and alcoholic fermentation. Kefir products are commonly used as food vehicles to deliver health-promoting materials including kefran and lactic acid bacteria to consumers. The aim of this study was to develop a freeze-dried starter culture without yeast and assess the suitability of kefir-like dairy products for the growth of lactic acid bacteria and the acidification of milk. Pasteurized whole milk (SNF 8.5%) stored at $25^{\circ}C$ was aseptically inoculated with starter cultures (0.002% w/v); it was kept at $25^{\circ}C$ until the pH attained a value of 4.6. Ten grams of the kefir-like product sample was diluted with 90 mL of 0.15% peptone water diluent in a milk dilution bottle, followed by uniform mixing for 1 min. Viable cells of Lactobacillus species were enumerated on modified-MRS agar (pH 5.2), with incubation at $37^{\circ}C$ for 48 h. Viable cells of Lactococcus species were enumerated on M17-lactose agar, with incubation at $32^{\circ}C$ for 48 h. The pH attained a value of 4.6 after fermentation for 9 h 30 min (Starter 1), 9 h 45 min (Starter 2), and 12 h (Starter 3). The viable cell count of Lactobacillus sp. and Lactococcus sp. was initially $10^5{\sim}10^6CFU/g$; it increased significantly to $10^9CFU/g$ after 12 h of incubation. During the storage of the kefir-like products at $4^{\circ}C$ for 1 4 days, the total viable cell numbers were unchanged, but the pH decreased slightly. The consistency of the kefir products increased gradually during the storage. The organoleptic properties of the kefir products fermented using the new starter culture are more desirable than those of commercial kefir. These results suggest that the newly developed starter culture without yeast could be suitable for kefir fermentation.

• The Korean Journal of Food And Nutrition
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• v.12 no.1
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• pp.77-84
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• 1999

The purpose of this study is to establish a rapid preparation method of Dongchimi-juice having favor-able flavor and high antibacterial activity against undesirable bacteria in Naengmyon-broth by using high antibacterial strains of lactic acid bacteria Lactobacillus homohiochii B21 and leuconostoc mesenteroid-es subsp. mesenteroides C16 as Dongchimi starter. When the two strains of lactic acid bacteria were used as starter mixed culture was better than single culture in acid production and antibacterial activity. When starter was not inoculated in Dongchimi fermentation the numbers of Gram negatives and colifor-ms were remarkably increased in early phase and antibacterial activity could scarcely be detected. But when starter was inoculated the numbers of Gram negatives and coliforms were sharply decreased from early phase and antibacterial ctivity was high. When Dongchimi was made with heat sterilized mat-erials and starter there were no Gram negatives and coliforms and antibacterial activity was high. The antibacterial activity of starter inoculated Dongchimi was maximum in 2 days of fermentation at 2$0^{\circ}C$ and was scarcely detected in six days. In consideration of coliform counts antibacterial activity and the flavor of Dongchimi the preparation method in which all materials were heat treated at 8$0^{\circ}C$ for 15 min-utes and inoculated with mixed starter of the two strains and fermented for 2 days at 2$0^{\circ}C$ was thoug-ht to be good.

• Microbiology and Biotechnology Letters
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• v.47 no.2
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• pp.211-219
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• 2019

The effect of microencapsulation on previously isolated Lactobacillus delbrueckii 94/L4 as starter culture for yogurt, and Lactobacillus casei 97/L3 as a probiotic candidate was investigated. Preliminary results showed that L. delbrueckii 94/L4 exhibited tolerance to bile, unlike L. casei 97/L3. Freeze drying significantly (p < 0.05) reduced the viability of both isolates by log 0.71-2.70. Although microencapsulation preserved the viability of L. casei 97/L3 cells exposed to simulated gastrointestinal tract conditions for 120 min, it did not impart significant (p < 0.05) protection against loss of viability during the first 30 min of exposure. Conversely, microencapsulated L. delbrueckii 94/L4 with the addition of Streptococcus thermophilus 24/S1 as starter culture was successfully incorporated into milk to form yogurt, yielding a significantly (p < 0.05) improved product quality.

• Journal of the Korean Society of Food Culture
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• v.34 no.2
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• pp.208-216
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• 2019

Leuconostoc spp. are generally utilized as kimchi starters, because these strains are expected to have beneficial effects on kimchi fermentation, including improvement of sensory characteristics. Here, we developed a detection method for verifying the presence of the kimchi starter Leuconostoc mesenteroides WiKim33, which is used for control of kimchi fermentation. A primer set for multiplex polymerase chain reaction was designed based on the nucleotide sequence of the plasmids in strain WiKim33, and their specificity was validated against 45 different strains of Leuconostoc spp. and 30 other strains. Furthermore, the starter strain consistently tested positive, regardless of the presence of other bacterial species in starter kimchi during the fermentation period. Our findings showed that application of a strain-specific primer set for strain WiKim33 presented a rapid, sensitive, and specific method for detection of this kimchi starter strain during natural kimchi fermentation.

• The Korean Journal of Food And Nutrition
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• v.17 no.1
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• pp.8-17
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• 2004

The effect of chlorella extract on the growth and acid production of yoghurt starter was investigated in order to prepare the yoghurt added with chlorella extract. The various levels of chlorella extract powder were added to skim milk medium and the medium was fermented by single or mixed culture of 4 types of lactic acid bacteria such as Streptococcus thermophilus, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus bulgaricus. The changes in acid production(pH, titratable acidity) and number of viable cells of the medium during fermentation in skim milk added with chlorella extract powder have determined. When chlorella extract powder was added to skim milk medium at the levels of 0.5%, 1.0%, 2.0%, and 3.0%, the addition of 0.5% chlorella extract powder with the single culture of Str. thermophilus, Lac. casei, and Lac. bulgaricus showed the highest number of viable cell counts after 9 hours incubation. And also all single cultures of the yoghurt starter produced the higher amounts of acid with the addition of 0.5% chlorella extract powder. When chlorella extract powder was added to the medium at the levels of 0.25%, 0.5%, 1.0%, and 2.0%, the addition of lower lever(0.25∼0.5%) of chlorella extract powder with the mixed culture of the lactic acid bacteria showed more the acidity of pH and the number of viable cell counts. Among the treatments tested, the addition of 0.25% chlorella extract powder with the mixed culture of Str. thermophilus and Lac. casei produced the highest number of viable cell counts after 12 hours incubation. Therefore it was suggested to manufacture the yoghurt with the addition of 0.25% chlorella extract powder and the inoculation of mixed culture of Str. thermophilus and Lac. casei for on the stimulation of growth of the yoghurt starter.