• Food Science of Animal Resources
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• v.33 no.6
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• pp.787-795
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• 2013

This study was carried out to investigate the characteristics of goat and cow milk yogurts containing high-exopolysaccharide fermented by Streptoccous thermophilus LFG isolated from kefir. The pH of cow milk yogurt was higher than that of goat milk yogurt. The contents of lactic acid was greater in goat milk yogurt (743.9-1043.8 mg/100 g) than in cow milk yogurt (441.6-709.9 mg/100 g). The numbers of survival lactic acid bacteria were the greatest in goat milk yogurt fermented by Str. thermophilus LFG. Viscosity was greater in cow and goat milk yogurts cultured by Str. thermophilus LFG than in yogurts by Str. thermophilus TH3. Syneresis of yogurt fermented by Str. thermophilus LFG was 9.6-16.1% and 28.2-31.8% in yogurt fermented by Str. thermophilus TH3 after 10 d storage at $4^{\circ}C$. Flavor compounds identified from goat milk were acetone, ethylbutanoate, ethyl-3-methylbutyrate, ethyl-2-butenoate and ethylhexanoate, and those from cow milk were ethylbutanoate, acetone, 2-heptanone and acetoin. Flavor compounds detected from goat milk and cow milk yogurts were acetic acid, butanoic acid, butanol, diethylcarbinol, acetone, diacetyl, decane, 2-methyl-3-pentanone, hexanal, 2-heptanone, acetoin, benzaldehyde, dimethyldisulfide, and dimethyltrisulfide. In sensory evaluation, overall preference and texture values were higher in goat milk yogurt fermented by Str. thermophilus LFG than in cow milk yogurts and the yogurt fermented by mixed culture resulted in the highest score.

• Food Science of Animal Resources
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• v.25 no.3
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• pp.357-364
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• 2005

To search probiotic microorganisms, we isolated Lactobacillus sp. from kefir, The Lactobacillus sp. strain showed $99.5\%$ of identity to species Lactobacillus rhamnosus by API kit. Lactobacillus rhamnosus showed high resistances to acidic environment, which grew well even at pH 2.0 and $1.0\%$ bile salt Enzyme activity of Lactobacillus rhamnosus was higher in amylase ($0.673\;{\mu}mol/min/mg$) than that in xylanase ($0.288\;{\mu}mol/min/mg$), cellulase($0.117\;{\mu}mol/min/mg$) and phytase($0.269\;{\mu}mol/min/mg$). Especially, the Lactobacillus rhamnosus showed high heat stability which remained $1{\times}10^6\;CFU/ml$ at $60^{\circ}C$. The maximum numbers of Lactobacillus rhamnosus on growth owe was reached at 24 h fermentation and pH was decreased to 4.6. The resistances of Lactobacillus rhamnosus to acidic pH and bile salt were better than that of Lactobacillus acidophilus used as control. When Lactobacillus rhamnosus was cultured with E. coli in MRS broth, E. coli was disappeared after 18 h. These result suggest that the isolated Lactobacillus rhamnosus has a useful probiotics properties.

• Journal of Animal Science and Technology
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• v.48 no.2
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• pp.307-314
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• 2006

To search direct fed microbials, we isolated a Candida sp. from kefir grain. The isolated Candida sp. strain showed 99.8% of identity to the species of Candida kefyr by API 20C kit. Enzyme activity of Candida kefyr was higher in amylase (0.33±1.12μmol/min/mg) than that in phytase (0.052±0.98μmol/ min/mg) cellulase(0.051±μmol/min/mg) and xylanase (0.011±0.98mol/min/mg). The maximum numbers of Candida kefyr in growth curve were reached at 30 h fermentation. Candida kefyr showed high resistances to acidic environment, which was not perfectly extincted even at pH 2.0. And it showed high tolerance to bile salt which had almost 97.2% of survival in the presence of 1.0% bile salt.Especially, Candida kefyr showed high heat stability which remained 10% of initial microorganisms at 60℃. Candida kefyr was not generally inhibited by most of 11 antibiotic agent which contained tetracycline groups. These results suggest that the isolated Candida kefyr has a useful properties as probiotics.

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2002.11a
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• pp.196-196
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• 2002

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2001.11a
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• pp.140-140
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• 2001

• Proceedings of the Korean Society of Food and Cookery Science Conference
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• 2004.10a
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• pp.121-121
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• 2004

• Journal of Dairy Science and Biotechnology
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• v.38 no.4
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• pp.197-206
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• 2020

This study was conducted to evaluate the antibacterial activity against Cronobacter sakazakii and Salmonella enteritidis as well as the sensory attributes of milk products supplemented with various concentrations (control, 0.5%, 1.0%, 1.5%, and 2.0%) of clove oil. In this study, clove oil was shown to have strong antibacterial activities. In addition, all the samples were assessed by ten researchers trained in five sensory attributes, namely, taste, flavor, color, texture, and overall acceptability. Compared to the control, 5% clove oil supplemented was the best in market milk, while in yogurt and kefir, 1.0% supplementation was the best. In terms of sensory attributes, the low score of color and flavor of market milk, yogurt, and kefir is attributed to the characteristics of the supplemented clove oil. Consequently, this study presents the possibility of producing bio-functional milk products supplemented with clove oil, and for controlling the growth of foodborne pathogenic bacteria in milk products using clove oil.

• Korean Journal of Microbiology
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• v.47 no.3
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• pp.218-224
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• 2011

Lactic acid bacteria (LAB) OA18 was isolated from yogurt prepared by using Kefir Grain as a starter. The OA18 strain was a Gram-positive, cocci-type bacterium, and able to grow anaerobically with $CO_2$ production. The OA18 strain grew well on MRS broth supplemented with 50 mM arginine at $30-37^{\circ}C$ and pH of 7.0-9.0. The optimum temperature and pH for growth are $37^{\circ}C$ and pH 7.0. The isolate fermented ribose, D-glucose, cellobiose, D-trehalose, but not L-xylose, D-melibiose, and inositol. The 16S rRNA gene sequence of the isolate showed 99.8% homology with the Enterococcus faecalis 16S rRNA gene (Access no. AB012212). Based on the biochemical characteristics and 16S rRNA gene sequence analysis data, it was identified and named as E. faecalis OA18. The E. faecalis OA18 strain showed a high ornithine-producing capacity in the presence of arginine and also showed an antimicrobial activity against Streptomyces strains such as Streptomyces coelicolor subsp. Flavus, S. coeruleorubidus, S. coeruleoaurantiacus, S. coelicolor, S. coeruleoprunus. The cell growth of E. faecalis OA18 strain was maintained in MRS broth with a NaCl concentration of 0-7%.

• Food Science of Animal Resources
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• v.29 no.2
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• pp.143-150
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• 2009

This study was carried out to investigate the properties of crude exopolysaccaride (CEPS) produced by Streptococcus thermophilus LFG in goat milk. The yields of CEPS from yogurt cultured with Str. thermophilus LFG were greater at higher temperatures $(40-45^{\circ}C)$ than at lower temperatures $(30-35^{\circ}C)$. Goat milk yogurt had lower viscosity values than cow milk yogurt. However, the CEPS yield was higher in goat milk yogurt than in cow milk yogurt. The yields of CEPS from yogurt were also higher in cultured milk containing 3% glucose (14-21%), and 3% sucrose (4-16%) relative to the control yogurt. Antioxidant activities were higher in goat milk yogurt supernatant (21%) and its CEPS (28%) than cow milk yogurt supernatant (11%) and its CEPS (24%). The amino acid contents of CEPS were higher in yogurt using goat milk than that using cow milk. The CEPS extracted from goat milk yogurt produced by Str. thermophilus LFG consists of carbohydrate (37% w/w) and protein (63% w/w). The CEPS consisted of monosaccharides such as glucose 56.45% (w/w), galactose 42.35% (w/w), galactosamine 1.37% (w/w), glucosamine 1.09% (w/w) and fucose 0.27% (w/w).

• The Microorganisms and Industry
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• v.19 no.3
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• pp.46-48
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• 1993

현재 유산균은 요구르트, 치즈, 케피어(kefir), 에시도필러스 밀크(acidophilus milk), 비피더스 밀크(bifidus milk), 쿠미스(kumiss), 발효버터(fermented butter), 유산균음료, 빵 등 식품의 천연 방부제, 채소절임, 발효두유(fermented soy milk), 정장제, 구강염증치료제, 사료 첨가제 등등 다양하게 이용되고 있다. 이것은 유산균에 대한 동결건조, 유전자 조작 등 첨단기술이 산업화로 연결되면서 그 이용성이 더욱 확장되고 있다. 유산균을 이용한 건강보조식품도 최근 몇년 사이에 선을 보이고 있지만 아직은 초보적인 단계이며 현재로선 유산균 발효식품과 유산균제제(의약품) 사이에서 뚜렷한 자기자리를 찾지 못하고 있는 실정이다.