• 한국동물위생학회지
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• 제18권2호
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• pp.163-176
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• 1995

Triphenyl Tetrazolium Chloride(TCC) reduction test is simple and sensitive to some residual antibiotics (especially to penicillin) in milk, but comparatively insensible to sulfo-namides. The volumn of sample is also large. Thus this study was undertaken to increase the detectable level of sulfonamides in raw milk. In this study, we used small transparent plastic hole and pulp disc instead of 10m1 test tube and made test medium in which was added 0.08%TTC, 0.3% agar, 10% skim milk, approximately $10^6$ CFU/ml streptococcus thermophilus and 5ppm Trimethoprim to enhance the sensitivity for sulfonamides The results of TCC reduction test by disc plate method were summarized as follows : 1. sensitivity to residual sulfonamides were much higher than official TCC reduction test. Detectable limites of sulfamethazine, sulfamerazine, sulfathiazole, sulfachloropy-ridazine, sulfadimethoxine, sulfamononethoxine, sulfadiazine and sulfaquinoxaline were 0.1-0.5ppm levels. 2. Detectable limites to some antibiotics were simillar or good than that of official method as 0.005-0.1ppm to three ${\beta}$ -lactams, 0.25-0.5ppm to one macrolide, 2-10ppm to three aminoglycosides, 0.2-0.5ppm to three tetracycline, 0.1-0.5ppm to chloramphenicol. 3. Only 0.1ml of milk was needed to test and the test medium could be stored appnoximatly 7days in the refrigerator. So test procedure was convenient than offcial method. 4. These results suggest that disc plate method is more useful to detect bacterial growth inhibition substances including sulfonamides in raw milk.

• 한국축산식품학회지
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• 제33권6호
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• pp.744-751
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• 2013

The objective of this study was to assess the physicochemical and sensory changes of a kefir manufactured by a two-step fermentation (MTY, $1^{st}$ step: $37^{\circ}C$ for 9 h; $2^{nd}$ step: $24^{\circ}C$ for 15 h) and compare it with kefirs produced by two conventional methods (GTY, fermentation at $37^{\circ}C$ for 24 h; KEY, $22^{\circ}C$ for 24 h). Rapid changes in pH and titratable acidity (TA) were observed in samples from all three manufacturing methods during fermentation process and storage period. Lactic acid bacteria (LAB) counts of MTY increased gradually up to 12 h of fermentation, reaching 9.28 Log CFU/mL, with maximum value observed in this experiment of 9.48 Log CFU/mL. The LAB counts of all samples decreased significantly during storage. The highest viscosity was observed for MTY (1750-1771 cPs), compared with the lowest viscosity observed for KEY (1250-1277 cPs). The viscosity of all samples increased slightly during storage (1250-1805 cPs, p<0.05), as well as carbon dioxide content (0.01-1.36%, p<0.05), except for GTY. The most significant increase in alcohol concentration during storage period was seen in MTY from 0.01% to 1.36% (p<0.05). MTY scored significantly higher in most items of the sensory analysis, indicating that the product manufactured by the two-step fermentation method is more acceptable compared with conventionally produced kefirs.

• 한국축산식품학회지
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• 제37권6호
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• pp.906-916
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• 2017

To investigate the effects of a single bacterium and a mixture of bacteria as probiotics in loperamide-treated animal models, loperamide (3 mg/kg) was administered to SD rats to induce constipation. The individual lactic acid bacterial doses, Enterococcus faecium (EF), Lactobacillus acidophilus (LA), Streptococcus thermophilus (ST), Bifidobacterium bifidum (BB), Bifidobacterium lactis (BL), Pediococcus pentosaceus (PP), and a mixture of the bacteria were orally administered to loperamide-induced constipated rats at a concentration of $10^8CFU/kg$ for 14 days. The weights and water contents of their stools were found to be significantly higher in PP, CKDB (mixture of 5 strains except PP), and CKDBP (CKDB+PP) groups than in the normal (constipation not induced) and the control (constipation-induced) groups (p<0.05). The intestinal transit ratio was significantly higher in all probiotic-treated groups than in the control group, and was the highest in the CKDBP group (p<0.05). The mucosal length and mucus secretion were significantly improved in all probiotic-treated-groups, as compared to that in the control group, and the CKDBP group was found to be the most effective according to immunohistochemistry (IHC) staining and total short chain fatty acid content analysis (p<0.05). Lastly, PP, CKDB, and CKDBP showed relatively higher Lactobacillus sp. ratios of 61.94%, 60.31% and 51.94%, respectively, compared to the other groups, based on metagenomic analysis.

• 한국지역사회생활과학회지
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• 제21권4호
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• pp.509-515
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• 2010

The physicochemical properties of the lactic acid fermented rice flour prepared using ABT-L(mixture of Lactobacillus acidophilus, Bacillus longum, Streptococcus thermophilus) were investigated. The efficiency of deproteinizing of lactic acid fermentated rice was higher than soaking fermented rice. The structural properties of lactic acid fermented rice flour showed slightly decreased inner particle size but maintained regular structural form. Molar mass and molar size after being treated with soaking or lactic acid fermentation were decreased. Amylograms except for pasting temperature of lactic acid fermented rice flours or soaking fermented rice flours were more significantly decreased than the control sample. The ratio of flours passed through 100 mesh and 150 mesh sieves of lactic acid fermented rice flours were higher than soaking fermented rice flours. Lactic acid fermented rice flours being passed through 100 mesh sieves showed finer particle flours than those treated with soaking. These results showed that lactic acid fermentation, which can have a high efficiency on the deproteinizing of rice, contributed to the changes of particle size and its distribution of rice flour.

• 한국미생물·생명공학회지
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• 제20권2호
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• pp.136-142
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• 1992

토양 분리균인 B.stearothermophilus chromosome의 유전자 은행으로부터 E.coli HB101 균주에 $\beta$-D-xylosidase 생산능력을 갖게하는 5.4Kb와 6.4Kb의 두 DNA 절편을 분리, pBR322에 크로닝하여 각각 pMG01과 pMG02의 재조합 플라스미드를 얻었다. 상기 두 B.stearothermophilus DNA 절편의 restriction map을 작성하고 이것을 기초로 하여 $\beta$-D-xylosidase 유전자인자의 위치를 확인함과 동시에 pUC18에 subcloning하여 각각 2.2kb와 1.0kb의 DNA 단편이 삽입된 $\beta$-D-xylosidase 양성의 pMG1와 pMG2를 분리하였다.

• 한국식품조리과학회지
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• 제31권1호
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• pp.98-102
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• 2015

Allium hookeri, a member of the onion family, has long been mainly cultivated for food and medicinal use in Southeast Asian countries, owing to its various biological properties. However, no studies of the anti-oxidative effects of fermented A. hookeri root extracts have been conducted to date. Therefore, this study investigated the effect of different starter cultures on the antioxidant activities of hot water extract of A. hookeri root by using the following five strains: Lactobacillus acidophilus, Bifidobacterum longum, Enterococcus faecium, Streptococcus thermophilus, and Saccharomyces cerevisiae. DPPH and ABTS radical scavenging activity, total phenolic acid contents, and total antioxidant capacity were higher in the hot water extract of A. hookeri root fermented with starter cultures than those of A. hookeri root. Among hot water extract of A. hookeri root fermented with starter cultures, fementing with S. cerevisiae showed the highest antioxidant activities. The results of this study provide new evidence of the anti-oxidative properties of A. hookeri root with starter cultures, indicating that it may be highly valuable as a natural product owing to its high-quality functional components.

• 한국축산식품학회지
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• 제33권3호
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• pp.335-340
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• 2013

This study screened for radio-resistant strains lactic acid bacteria (LAB) by evaluating their capability to survive exposure to ionizing radiation. Ten strains of LAB - Lactobacillus bulgaricus, Lactobacillus paracasei, Lactobacillus casei, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus delbruekii, Lactococcus lactis, Streptococcus thermophilus, Bifidobacterium breve, and Pediocuccos pentosaceus - were selected and subcultuted twice. The LAB was then further cultured for 3 d at $37^{\circ}C$ to reach 7-10 Log colony-forming units (CFU)/mL prior to irradiation and immediately exposed to gamma rays or electron beams with absorbed doses of 0, 1, 2, 3, 4, 5, 6, 8, and 10 kGy. Gamma irradiation gradually decreased the number of the tested viable LAB, and the effect was irradiation dose dependent. A similar effect was found in electron beam-irradiated LAB. Radiation sensitivity of LAB was calculated as $D_{10}$ values, which ranged from 0.26 kGy to 0.9 kGy and 0.5 kGy to 1.44 kGy with exposure to gamma and electron beam irradiation, respectively, in all tested LAB. L. acidophilus was the most resistant to gamma and electron beam irradiation, with $D_{10}$ values of 0.9 kGy and 1.44 kGy, respectively. These results suggest that L. acidophilus might be suitable for the preparation of probiotics as direct-fed microbes for astronauts in extreme space environments.

• 한국식품위생안전성학회지
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• 제5권1호
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• pp.27-34
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• 1990

유산균이 생성하는 다당류에 관한 연구의 일환으로서 발효유 제품의 종균으로 널리 사용되고 있는 Str. themophilus, Lb. bulgaricus, Lb. casei 등을 10% 환원멸균 탈지유에 배양하면서 다당류 생성에 따른, 우유 배양액 점도의 경시적 변화 및 다당류의 최적 생성 조건에 대하여 조사하였다. 1. 시험균 중에서 Str. thermophilus 510이 가장 높은 점도를 나타냈으며 $41^{\circ}C$ 배양 5일째에 5,000 CP로서 다른균에 비해서 1,000 CP 이상 높았다. 2. 인공합성배지를 사용하여 흡광도를 측정한 결과 $41^{\circ}C$에서의 흡광도가 가장 높았으며 다당류 합성을 위한 탄소원으로서는 Sucrose의 이용성이 1~5% 농도에서 가장 높았다. 3. 다당류 합성효소의 금속염에 대한 영향을 살펴본 결과 $Mg^{++}$의 효과가 인정되었다.

• 한국축산식품학회지
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• 제36권1호
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• pp.90-99
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• 2016

This study evaluated the effects of two Korean traditional plant extracts (Diospyros kaki THUNB. leaf; DK, and Nelumbo nucifera leaf; NN) on the fermentation, functional and sensory properties of herbal yogurts. Compared to control fermentation, all plant extracts increased acidification rate and reduced the time to complete fermentation (pH 4.5). Supplementation of plant extracts and storage time were found to influence the characteristics of the yogurts, contributing to increased viability of starter culture and phenolic compounds. In particular, the increase in the counts of Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus was highest (2.95 and 1.14 Log CFU/mL respectively) in DK yogurt. Furthermore, supplementation of the plant extracts significantly influenced to increase the antioxidant activity and water holding capacity and to produce volatile compounds. The higher antioxidant activity and water holding capacity were observed in NN yogurt than DK yogurt. Moreover, all of the sensory characteristics were altered by the addition of plant extracts. Addition of plant extracts increased the scores related to flavor, taste, and texture from plain yogurt without a plant extract, as a result of volatile compounds analysis. Thus, the overall preference was increased by plant extracts. Consequently, supplementation of DK and NN extracts in yogurt enhanced the antioxidant activity and physical property, moreover increased the acceptability of yogurt. These findings demonstrate the possibility of using plant extracts as a functional ingredient in the manufacture of herbal yogurt.

• 한국식품과학회지
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• 제27권6호
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• pp.939-943
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• 1995

본 실험에서는 Lactobacillus acidophilus, Bifidobacterium bifidum, Streptococcus salvarius subsp. thermophilus의 혼합균주를 이용한 호상 요구르트의 제조시 $10^{\circ}C$에서 15일간의 저장기간에 따른 휘발성 향미성분과 요구르트 향미의 변화를 조사하였다. 저장기간이 길어짐에 따라 diacetyl을 제외한 acetaldehyde, acetone, ethanol, 2-butanone과 2-heptanone의 함량은 지속적인 증가 경향을 보였다. 그 중 acetaldehyde, acetone과 ethanol 성분은 현저히 증가하였다. 호상 요구르트의 향미는 15일간의 저장기간동안 유의적 차이를 보이지 않았고, 관능검사에 따른 이취는 증가하였다. 요구르트의 휘발성 향미 성분과 관능검사결과와의 상관 관계는 acetone과 향미와는 (-)의 관계로, ethanol과 이취와는 (+)관계로 나타났으며, 그 유의성이 인정되었다(p<0.05). $10^{\circ}C$에서 15일간의 저장기간에 따른 호상 요구르트의 휘발성 성분 함량과 요구르트의 향미 변화를 조사한 결과, 15일간의 저장은 거의 영향을 끼치지 않는 것으로 나타났다.