• Food Science and Preservation
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• v.24 no.6
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• pp.865-870
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• 2017

Yogurt is produced by fermentation of milk using bacteria known as "yogurt cultures". Most of these bacteria are probiotics such as Lactobacillus delbrueckii subsp. bulgaricus, Lb. rhamnosus, Streptococcus thermophilus, and Bifidobacterium. The domestic fermented milk market is increasing, and about 30 companies are producing yogurt. The purpose of this study was to analyze the quality characteristics of domestic commercial liquid yogurt. Total 30types of commercial yogurts were sampled and their physicochemicial properties, including pH, sugar content, acidity, viscosity, and microbial characteristics of lactic acid bacteria counts, were measured. Commercial liquid type yogurt showed a pH of 4.5, sugar content of 7.4-21.2%, total acid content of 0.4-0.9%, and viscosity of 0.1-250 cP. In terms of microbial populations, lactic acid bacteria counts were 7.2-11.3 log CFU/mL and anaerobic lactic acid bacteria counts were 8.0-11.5 log CFU/mL. The quality characteristics differed depending on the constituents of the sample and the microorganisms used. These results are related to the quality characteristics of yogurts and are useful for identifying new trends in the domestic fermented milk industry.

• Korean Journal of Food Science and Technology
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• v.52 no.5
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• pp.524-528
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• 2020

The aim of this study was to enhance the use of wheat bran in lactic acid bacteria (LAB) fermentation. LAB fermentation of wheat bran and the flavor components and amino acids of fermentation products were analyzed using gas chromatography-mass spectrometry (GC/MS) and high-performance liquid chromatography (HPLC). The results showed that total flavor components increased by 93% and 73% in the animal-based LAB mixture (T2) and plant-based LAB mixture (T3), respectively, after fermentation. Among these components, 2,3-butanedione (diacetyl), known for its buttery flavor, was detected at concentrations of 18.44 ng/g (T2) and 16.95 ng/g (T3). Levels of hexanal and nonanal, which causes off-flavor components in wheat bran, dramatically decreased after T2 fermentation; similarly, levels of total free amino acids decreased by 37.6% (T2) and 36.7% (T3) after fermentation. This may explain why some components were bound to volatile compounds during LAB fermentation. These results suggest that LAB-fermented wheat bran is a potential value-added food material.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.3
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• pp.400-407
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• 2017

This study investigated the antioxidant properties of yangha(Zingiber mioga Rosc) and quality characteristics of kimchi with added yangha during a 21-day fermentation process at $4^{\circ}C$. Yangha was added to salted cabbage at concentrations of 0, 5, 10, and 15% (w/w). The quality characteristics of kimchi with added yangha were determined by measuring pH, salinity, mineral contents, lactic acid bacteria amounts, color value and sensory evaluation. From the results, total phenolic ($3.85{\mu}M$ quercetin equivalent/g) and total flavonoids ($0.49{\mu}M$ quercetin equivalent/g) contents were measured in yangha. The number of lactic acid bacteria of kimchi with added yangha significantly increased with increasing yangha content, especially 10%. The brightness value increased with increasing yangha content. However, the redness tended to decrease by the addition of 10% and 15% yangha. The consumer acceptability score for the kimchi with added 10% yangha ranked significantly higher than that of the other groups in overall acceptability, taste, flavor, and color(p<0.05). From these results, we suggest that yangha may be used as a natural antioxidant and that it is a good food ingredient for increasing the functionality and consumer acceptability of kimchi.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.9
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• pp.1273-1279
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• 2016

The objectives of this study were to determine an optimal cultivation time for populations of yeast and lactic acid bacteria (LAB) co-cultured in fermented milk and effects of soybean meal fermented milk (SBMFM) supplementation on rumen degradability in beef cattle using nylon bag technique. The study on an optimal cultivation time for yeast and LAB growth in fermented milk was determined at 0, 4, 8, 24, 48, 72, and 96 h post-cultivation. After fermenting for 4 days, an optimal cultivation time of yeast and LAB in fermented milk was selected and used for making the SBMFM product to study nylon bag technique. Two ruminal fistulated beef cattle ($410{\pm}10kg$) were used to study on the effect of SBMFM supplementation (0%, 3%, and 5% of total concentrate substrate) on rumen degradability using in situ method at incubation times of 0, 2, 4, 6, 12, 24, 48, and 72 h according to a Completely randomized design. The results revealed that the highest yeast and LAB population culture in fermented milk was found at 72 h-post cultivation. From in situ study, the soluble fractions at time zero (a), potential degradability (a+b) and effective degradability of dry matter (EDDM) linearly (p<0.01) increased with the increasing supplemental levels and the highest was in the 5% SBMFM supplemented group. However, there was no effect of SBMFM supplement on insoluble degradability fractions (b) and rate of degradation (c). In conclusion, the optimal fermented time for fermented milk with yeast and LAB was at 72 h-post cultivation and supplementation of SBMFM at 5% of total concentrate substrate could improve rumen degradability of beef cattle. However, further research on effect of SBMFM on rumen ecology and production performance in meat and milk should be conducted using in vivo both digestion and feeding trials.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.4
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• pp.264-269
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• 2022

The present study investigated effects of microbial additives on the floor of Hanwoo steer manure in barn. The treatment following: without additives (CON); additives (AMA). Each treatment used 3 barns as replication and each barn contained 5 Hanwoos. The Hanwoo steer manure in barns was sub-sampled from 5 sides of pen at 0, 4 and 12 weeks. The sub-samples were used for analyses of chemical compositions, microbial counts, gas emissions and compost maturity. The concentrations of moisture, organic matter, total nitrogen and carbon-to-nitrogen (C/N ratio) of Hanwoo steer manure before the microbial additives were each 59.1%, 83.2%, 1.78% and 50.0%, respectively. The counts of lactic acid bacteria, Yeast, Bacillus subtilis, and Escherichia coli (E. coli) were each 5.94, 6.83, 7,28 and 5.52 cfu/g, but Salmonella was not detected. The ammonia-N gas was 4.67 ppm, but hydrogen sulfide gas was not detected. After 4 weeks, moisture, organic matter, total nitrogen, pH and yeast count were lowest (p<0.05). The lactic acid bacteria, yeast, Escherichia coli (E. coli) and ammonia-N gas were not effects of microbial additives. All treatments was not detected at Salmonella count and hydrogen sulfide emission, and compost maturity was completed. After 12 weeks, the lactic acid bacteria and Bacillus subtilis were highest in AMA, while moisture, yeast and E. coli were lowest (p<0.05). The ammonia-N gas was not effect by microbial additive. Salmonella and hydrogen sulfide emission were not detected in all treatments, and compost maturity was completed. Therefore, in present study, the microbial additive did not affect of gas and compost maturity, but the pathogenic microorganism such as E. coli, were inhibited by microbial additives.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.773-779
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• 1999

This study was conducted to determine the changes in the contents of vitamin C and fermentation characteristics of kimchi on different Chinese cabbage variety(Koreangji Yureum: KY, Kalak Shin Il Ho: KS) and fermentation temperature(5oC, 15oC). Kimchi were fermented at 5oC and 15oC for 140 days and 25 days respectively. In all samples, total acidity increased, and the pH, total sugar and reducing sugar content decreased as the fermentation proceeded. Also, the number of lactic acid bacteria reached the maximum at the optimum fermenting stage. On the other hand, total ascorbic acid, dehydroascorbic acid and ascorbic acid from individual kimchi solid tissue significantly decreased with fermentation periods, however, increased kimchi liquid at the 7day in KS 15(kimchi prepared with Kalak Shin Il Ho at 15oC), KY 15(kimchi prepared with Korangji Yureum at 15oC) and at the 65day in KY 5(kimchi prepared with Korangji Yureum at 5oC) respectively. Therefore, different fermentation temperature as well as variety affected ascorbic acid contents and chemical characteristics of kimchi.

• Journal of Microbiology and Biotechnology
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• v.30 no.7
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• pp.1060-1066
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• 2020

This study was focused on developing and obtaining a kimchi starter for use in commercial kimchi production. Kimchi varieties made with selected starters are of high quality, have high levels of mannitol, and extended shelf life. The starters were screened for properties such as mannitol production, low gas/acid production, and acid resistance. Finally, kimchi fermentation testing was performed using selected LAB starters. Kimchi samples were prepared with lactic acid bacteria (LAB) starters, including Leuconostoc mesenteroides PBio03 and Leuconostoc mesenteroides PBio104. The LAB starters are isolated from kimchi and can grow under pH 3.0 and low temperature conditions of 5℃. Four kimchi samples were fermented and stored for 28 days at 5℃. The kimchi samples made with starters (PBio03 and PBio104) had better quality (production of mannitol and maintenance of heterofermentative LAB dominance) than the non-starter kimchi samples. In the starter kimchi, Leu. mesenteroides was the dominant LAB, comprising 80% and 70% of total LAB counts at 7 and 21 days, respectively. Mannitol content of the kimchi with Leu. mesenteroides PBio03 was 1,423 ± 19.1 mg/100 g at 28 days, which was higher than that of the non-starter kimchi sample (1,027 ± 12.2 mg/100 g). These results show the possibility of producing kimchi with improved qualities using Leu. mesenteroides PBio03 and PBio104 as starters.

• Journal of Life Science
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• v.14 no.5
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• pp.747-751
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• 2004

The effect of yogurt containing Hamcho (Salicornia herbacea) extract (Hamcho yogurt: HY) on the lipid concentrations in male Sprague-Dawley rats fed a cholesterol diet were studied. Rats were assigned three groups in the experiment; cholesterol diet (the CHOL group), cholesterol diet plus yogurt by lactic acid bacteria (the Y group) or cholesterol diet plus yogurt supplemented Hamcho extract by lactic acid bacteria (the HY group). Fermented milk with or without Hamcho extract in the diet supplemented at the levels 5.0% for 3 weeks. The concentrations of total cholesterol and bile acid in serum was significantly lower in the HY group than the CHOL group. This effect was also observed in rats fed a diet supplemented fermented milk. This cholesterol-lowering effect was more pronounced in the HY group compared to the Y group. The atherogenic index was significantly lower in the HY or Y groups than the CHOL group. The concentration of non esterified fatty acid in serum was significantly lower in the HY group than the CHOL and the Y groups. These results suggested that Hamcho yogurt exert the hypocholesterolemic effect in cholesterol fed rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.24 no.6
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• pp.990-997
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• 1995

Effect of preparation method on Yulmoo kimchi(watery kimchi prepared with Yulmoo, leaf radish) fermentation was investigated by measuring physicochemical, microbiological and sensory properties for 20 days. Yulmoo kimchi was fermented at 4$^{\circ}C$ after keeping at room temperature(27$\pm$0.5$^{\circ}C$) for 8 hours. Four types(A, B, C, D) of Yulmoo kimchi were prepared. Sample A was made without wheat flour paste and red pepper powder and sample B was made with wheat flour paste. Sample C was made with red pepper powder, and sample D was made with wheat flour paste and red pepper powder. pH was slowly lowered and stabled after 10 days in all samples. Total acid content increased in all samples. Reducing sugar content initially increased and decreased thereafter. Especially, reducing sugar content of sample B increased in the early stage of fermentation and maintained initial reducing sugar content after 20 days. Total vitamin C content reduced during fermentation in all samples. Especially initial total vitamin C content of sample D increased more than those of other samples relatiely. Lightness and yellowness showed no difference, but on the other hand redness increased gradually in all samples. The number of lactic acid bactgeria reached maximum value in 10~13 days with the total cell numbers and gradually decreased thereafter in all samples. The number of lactic acid bacteria and total cell number of sample D was much more than those of any other samples. As a result of the sensory evaluation, Yulmoo kimchi showed significant difference in all characteristics. Sample D showed the highest scores in all characteristics before 10 days of fermentation. However, after 10 days sample B showed the highest scores.

• Food Science and Preservation
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• v.8 no.1
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• pp.60-65
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• 2001

To investigate the effect of Acetobacter on qualities of potato vinegars, potato vinegars were produced through acetic acid fermentation using 3 Acetobacters such as Acetobacter sp. PA97, Acetobacter sp. PA96 and Acetobacter pasterianus JK 99. There were little difference in pH(2.90∼3.09) and total acidities(5.30∼5.60%) of 3 potato vinegars. However potato vinegar(II) fermented by Acetobacter sp. PA96 showed a little difference in color values with other potato vinegars. Except acetic acid in each potato vinegars, the contents of citric acid, oxalic acid, succinic acid were high in potato vinegar(I), malic acid in potato vinegar(II) and lactic acid in potato vinegar(III). The contents of glutamic acid alanine, histidine and proline were high in all potato vinegars. The major volatile components in 3 potato vinegars were acetic acid, isoamyl acetate, isobutyl acetate, 3-methyl-1-butanol, 3-methyl-butanoic acid and phenethyl alcohol. Also composition ratio of volatile components was a little difference among 3 potato vinegars.