• Korean Journal of Veterinary Service
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• v.18 no.2
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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.

• Food Science of Animal Resources
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• v.33 no.6
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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.

• Food Science of Animal Resources
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• v.37 no.6
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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.

• The Korean Journal of Community Living Science
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• v.21 no.4
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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.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.136-142
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• 1992

Bacillus stearothemophilus isolated from soil was identified to express multiple extracellular xylanases. Two HindIII restriction fragments of 5.4 and 6.4 kb from B. stearothermophilus genomic DNA were cloned into pBR322 to obtain recombinant plasmids pMG0l and pMG02, respectively, which enabled E. coli HBlOl cells to produce $\beta$-D-xylosidase activity. By subcloning into pUC18 and Southern blotting, the loci of the $\beta$-D-xyiosidase genes were elucidated to be on non-homologous DNA fragments of 2.2 kb from pMGOl(pMG1) and 1.0 kb from pMG02(pMG2), respectively. The two enzymes produced in E. coli cleaved xylobiose, xylotriose, xylotetrose and xylotetrose to produce xylose as a major end product. The gene on pMG1, distinct from that on pMG2 was observed to encode a bifunctional protein that displayed both P-D-xylosidase (EC.3.2.1.37) and a-L-arabinofuranosidase activities (EC.3.2.1.55).

• Korean journal of food and cookery science
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• v.31 no.1
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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.

• Food Science of Animal Resources
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• v.33 no.3
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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.

• Journal of Food Hygiene and Safety
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• v.5 no.1
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• pp.27-34
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• 1990

As a link in the studies on the extracellular polysaccharide by lactic acid bacteria, the experiment was conducted to investigate the viscosity variations of 10% reconstituted skim milk and optimum cultural conditions for the production of extracellular polysaccharide. 1. The viscosity of 10% reconstituted skim milk cultured by 8tr. thermophilu8 510 reached 5,000 CP at $41^{\circ}C$ and on 5 days. Because it was the highest value among the microorganisms tested, Str. thermophilu8 510 was chosen as a main test microoganism and studied on factors affecting maximum viscosity depending upon production of exopolysaccharide. 2. Absorbance of synthetic culture medium was highest at $41^{\circ}C$. Sucrose, in a member of carbohydrates, was the most effective carbon source for the production of exopolysaccharide within 5% concentration. 3. The production of exopplysaccharide was stimulated by $Mg^{++}$.

• Food Science of Animal Resources
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• v.36 no.1
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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.

• Korean Journal of Food Science and Technology
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• v.27 no.6
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• pp.939-943
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• 1995

This study was carried out to investigate neutral volatile compounds and sensory quality of yogurt during the storage of 15 days at $10^{\circ}C$. The yogurt was manufactured with mixed culture containing Lactobacillus acidophilus, Bifidobacterium bifidum and Streptococcus salvarius subsp. thermophilus. Among the volatile compounds, acetaldehyde, acetone and ethanol increased significantly, and 2-butanone and 2-heptanone increased slightly but diacetyl did not increase during the storage periods. In sensory test, the flavor scores of yogurt were not different during the period, but those of off-flavor were significantly different (p<0.05). In correlation between the volatile compounds and sensory test, there was negative correlation between acetone and yogurt flavor, but positive correlations between ethanol and off-flavor (p<0.05). The results suggested that the volatile flavor compound may not affect the quality of yogurt during 15d storage period at $10^{\circ}C$.