• Journal of Korean society of Dental Hygiene
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• v.21 no.5
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• pp.507-515
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• 2021

Objectives: The aim of this study was to evaluate the extent of the potential erosion of enamel induced by three different types of commercial fermented milk using the pH cycle model. Methods: Specimens were treated and soaked up in three types of fermented milk and in mineral water for 10 min, four times a day for 8 days, and all of the specimens were immersed in artificial saliva outside of treatment times. The microhardness of the surface was measured by a microhardness tester, and a scanning electron microscope (SEM) was used to identify the enamel surface morphology. Results: The differences in the surface microhardness (ΔVHN) of enamel were different among the groups (p<0.05). The four groups were in descending order of ΔVHN: the liquid type group, condensed-drink type group, condensed-stirred type group, and control group. The liquid type group had a higher ΔVHN than the other two fermented milk groups (p<0.05). Based on SEM observation, the most severe surface damage was due to the liquid type of fermented milk. Conclusions: Customers' careful discretion is advised when purchasing these types of fermented milk. This information is anticipated to be of much value in the prevention of dental erosion.

• The Journal of the Korea Contents Association
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• v.22 no.9
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• pp.583-591
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• 2022

The purpose of this study was to determine the incidence of dental erosion according to the type of lactic acid bacteria fermented oil and to identify a method for preventing dental erosion. For the lactic acid bacteria fermented milk, liquid fermented milk, condense-stirred type fermented milk, and condense-drink type fermented milk were used, and bovine tooth specimens used in the experiment were used. As a method to prevent dental erosion, the method of adding calcium to the lactic acid bacteria fermented milk, the method of applying high and low concentrations of fluoride to the teeth before exposure to the lactic acid bacteria fermented milk, and the method of applying these two methods together were measured to measure the preventive effect of dental erosion. As a result of immersing the specimen in the experimental beverage, the surface hardness of liquid fermented milk decreased the most. When comparing the difference in surface hardness before and after prophylaxis care, the Ca 2% group and the NaF 0.05%+Ca 0.5% group showed no significant difference from the negative control group, confirming that it is an effective method for preventing dental erosion. However, considering the change in taste and the stability of ingredients, a method of adding calcium at a low concentration rather than adding a high concentration of calcium is proposed. Therefore, it is recommended to use low-concentration calcium and low-concentration fluoride together to recognize the possibility of dental erosion when ingesting lactic acid bacteria and to prevent dental erosion caused by it.

• Proceedings of the Korean Nutrition Society Conference
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• 2001.05a
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• pp.220.1-220
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• 2001

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 2005.10a
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• pp.306-309
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• 2005

본 연구는 기능성 발효유로서 티벳산 발효유에서 분리한 효모(Kluyveromyces marxianus)와 유산균(Lactobacillus bulgaricus)의 혼합스타터를 이용한 발효유를 제조하여 배양 기간별 균수측정, pH, 적정산도, Alcohol 함량, 항암활성에 대해 알아보았다. 배양은 산도 0.68%, 최종 pH가 4.5가 되는 시점에서 마치게 되는데 이때의 배양 온도는 $30^{\circ}C$, 배양기간은 36시간이었다. 이때의 균수는 K. marxianus는 $5.3{\times}10^9$) CFU/mL, L. bulgaricus는 $3.2{\times}10^9$ CFU/mL였고 Alcohol 함량은 0.35%까지 증가하였다. 36시간 배양하여 제조된 발효유의 항종양 활성은 Hep-2에 대해서는 90.5%, HEC-1B는 86.6%, SW-156은 60.3%, SK-MES-1은 57.14%의 높은 항종양활성을 나타내었다. 이상의 결과 기존의 유산균 발효유에 효모를 첨가한 알코올 발효유의 제조가 가능하며, 제품의 항종양 활성의 측면에서도 높은 기능성을 나타내는 것으로 나타났다.

• Journal of Dairy Science and Biotechnology
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• v.15 no.1
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• pp.11-20
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• 1997

This study was designed to carry out an observation on the growth inhibitory effect of fermented milk by the the lactic acid bacteria such as Lactobacillus bulgaricus, L. acidophilus and L. cormatus against pathogenic Escherichia coli O157:H7 were studied in vitro. The results of this study were as follows : The BL broth culture of L. bulgaricus, L. acidophilus and L. cormatus gave a similar extent of growth inhibitory effects against the pathogenic E. coli O157:H7 were after incubation time within 18 hours. The inhibitory effects of the fermented milk were observed on the survival time of pathogenic E. coli O167:H7 in the various fermented milk at 37${\circ}$C shaking water bath (70 rpm) were after incubation time between 140 and 200 minutes. These results indicated that major portion of growth inhibitory effects of fermented milk with various lactic acid bacteria against pathogenic E. coli O157:H7 was possible due to the acid, and minor portion to the other antibacterial substances.

• Journal of Applied Biological Chemistry
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• v.61 no.1
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• pp.17-23
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• 2018

The purpose of this study was to produce mulberry extract and silk protein (MS) added yogurt fermented with vegetable lactic acid bacteria (Lactobacillus plantarum and Bacillus acidiproducens) and to determine their physicochemical properties and preference. The physicochemical properties were examined total phenol and antocyanins contents, viscosity, visible cell counts, chromaticity and sensory evaluation. Yogurt made with LP (PL) and BA (BA) had similar pH and titrable acidity and mulberry and MS addition made lower pH and higher titrable acidity than the control (YF) (p <0.05). The MS added yogurt exhibited adaptable acidity in the market. As expected, MS added yogurt had higher redness, and lower lightness and yellowness than no added one regardless of bacteria kinds, in chromaticity (p <0.05). MS added yogurt showed higher value of total phenols and anthocyanins than no MS added one. MS added yogurt also increased the number of live bacteria in the ascending order of than LP, BA, YF, LP + MS, and BA + MS. In sensory evaluation, BA + MS had the higher overall acceptance than the others. In conclusion, yogurt fermented with Lactobacillus plantarum and Bacillus acidiproducens was acceptable as much as the commercial Lactobacillus. Moreover, MS added yogurt fermented with Bacillus acidiproducens was the most preferred, based on physicochemical properties and overall acceptability for sensory evaluation.

• Journal of Food Hygiene and Safety
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• v.13 no.2
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• pp.164-170
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• 1998

In this study a commercial fermented milk produced in Korea and a Lactobacillus strain used for the product (L. casei) were found to affect mold growth and inhibit aflatoxin production by Aspergillus parasiticus ATCC 15517. Aflatoxins were determined using an HPLC system that consisted of a $C_{18}$ column and a fluorescence detector. When the fermented milk was added to the yeast-extract broth the levels of aflatoxin $B_{1}\;and\;G_{1}$ significantly decreased by 48.6~58.1% and 29.8~34.2%, respectively (p$B_{1}\;and\;G_{1}$ were found in comparison with the control (monoculture). L. casei was found to be very inhibitory to the growth of A. parasiticus for 5 days, but no significant difference of mycelial weight was observed between the mixed culture and control at the end of incubation. The pH values of the culture broth in mixed culture were observed to be significantly lower than those in monoculture (p

• Proceedings of the Korean Society for Food Science of Animal Resources Conference
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• 1995.11a
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• pp.109-109
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• 1995

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.555-563
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• 2004

The pH of beverages is known to be low and have, therefore, been implicated in the increasing incidence of erosion. Erosion is believed to be the predominant cause of teeth wear in children and young adults, although there will always be a contribution from attrition and abrasion. The aim of the present study was to evaluate the effect of yogurt on the progression of erosive demineralization in human enamel using demineralization model in vitro. In 4 yogurts, available on the market, pH, buffering capacity and the concentrations of calcium, phosphate and fluoride were determined. The buffering effect was determined by titration with NaOH. 50 milliliters of each drink was then titrated with 1M sodium hydroxide, added in 0.5 milliliters increments, until the pH reached about 7. Human deciduous enamel(n=40) samples were divided into four groups and exposed to 80ml of the yogurt for 30,60, 90 and 120min. Enamel surface microhardness(VHN) was examined before and after each exposure. 1. The average PH of fermented milk was 3.77 and this pH value was acidic enough to cause tooth erosion. 2. All of the fermented milks were found to be erosive(p<0.05) 3. The teeth exposed to the fermented milk all showed erosion like lesions and microhardness measurements showed that enamel surface hardness decreased proportionately with increased time of immersion in all tooth specimen groups. 4. After immersion for 30 and 60 minutes, reduction rate of microhardness values was not significantly different between the groups(p>0.05). However, after 90 and 120 minutes, reduction rate of each group was significantly different(p<0.05).

• Food Science of Animal Resources
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• v.26 no.2
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• pp.252-256
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• 2006

This study was carried out to investigate characteristics of acid and alcohol fermented milk by mixed starters made by Lactobacillus bulgaricus (KCTC 3635) and Kluyveromyces marxianus (KCTC 17212) for 36 hours when the curds were formed. Final pH and titratable acidity were about 4.5 and 0.68%, respectively. The viable cell counts of lactic acid bacteria and yeast for alcohol fermented milk were increased to $3.2{\times}10^9 CFU/mL$ and $5.3{\times}10^9 CFU/mL$, respectively. The ethanol contents increased to 0.35% during fermentation. Antitumor activities of the fermented milk against tumor cell lines, such as HEp-2, HEC-1B, SW-156 and SK-MES-1 showed to 86.6, 70.3, 60.4 and 57.14%, respectively.