• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.3
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• pp.352-358
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• 2009

The physicochemical properties of dextran culture fermented by Leuconostoc citreum S5 were evaluated by the addition of various polysaccharides and heat-treatment. The consistency of dextran culture increased with the addition of carrot juice residue (CJR) in submerged culture, resulting in the highest consistency of 150 $Pa{\cdot}s^n$ and viable cell counts of $2.36{\times}10^9$ CFU/mL at 20% level of CJR. The dextran culture showed the pseudoplastic behavior and its consistency was greatly increased with the addition of various polysaccharides at 2% level. Addition of glucomannan indicated the highest consistency of 1275 $Pa{\cdot}s^n$ and their heat-treatment resulted in the increase of consistency except for glucomannan. After heat-treatment, the fermented dextran culture containing CJR fortified with gellan gum and carrageenan showed great change in rheology, indicating the highest consistency and hardness value resulted in the great increase of elastic and viscous moduli. The dynamic viscoelastic properties of dextran culture were greatly increased by the heat-treatment after fortification of various polysaccharides. Thus, the consistency and viable cell counts of dextran culture were increased with the addition of CJR. The rheological properties of dextran culture were manipulated by the fortification of various polysaccharides and heat-treatment.

• Journal of the Korean Society of Food Culture
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• v.20 no.3
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• pp.337-340
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• 2005

Fourteen strains out of fifty six strains of lactic acid bacteria isolated from Kimchi showed a resistance to artificial gastric juice. In particular, lactobacilli AK 3, AK 7, BK 28, and DK 37 showed a strong resistance and their viable cell counts of the initial stage were no change after the 2 hours cultivation in an artificial gastric juice. All five lactic acid bacteria were used as starters in producing yogurts. The physicochemical characteristics of yogurts were examined. The original pH, titratable acidity, visicosity and viable cell counts of yogurts were $3.78{\sim}4.32,\;0.96{\sim}1.41%,\;1,659{\sim}2,348\;cps\;and\;1.1{\times}10^9{\sim}2.1{\times}10^9cfu/mL$, respectively. The ${\beta}-galactosidase$ activity reached maximum at 48 hr, and reduced gradually during incubation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.560-566
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• 1998

The bacteriocin produced by Lactobacillus sp. GM7311 showed strong inhibitory activity against the growth of three Gram positive bacteria, Listeria monocytogenes, Bacillus subtilis, and Staphylococcus aureus. When the bacteriocin was added to the culture at different phases, viable cells of all of the tested strains were decreased, although the most inhibited phase was different. Thereby, when the bacteriocin $(100\;Bu/m{\ell})$ was added to exponential and stationary phase of L. monocytogenes, the rapid reduction of viable cell counts occured. And, in the case of B. subtilis, the highest inhibitory effect occured at lag phase and mid-exponential phase by the addition of the bacteriocin under same condition as mentioned above. Also, we can observe the accelerated reduction of survivors counts for the all of the phase except stationary phase in the S. auresus. Transmission electron microscopic observation of L. monocrogenes and B. subtilis treated with bacteriocin revealed apparent Iysis of the cell wall and excretion of the cell contents, indicating bacteriolysis. Also, the amino acids and fatty acids compositions were different from controls. However, the Iysis of cell wall didn't occur in S. aureus, though the cytoplasmic materials were reduced. This result indicates that the bacteriocin inhibits the synthesis of nuclear materials such as DNA, RNA and proteins.

• Food Science and Preservation
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• v.11 no.1
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• pp.22-27
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• 2004

In order to endow mackerel fillet with antioxidant effect, functionality and remove fishy smell, chitosan, oligosaccaride, extracts of green tea, dill weed and ginger was used as soaking solution additives. Quality characteristics of soaked mackerel fillet(SMF) was investigated during storage temperature and time after vacuum packing with polyvinyl chloride film. From the results of VBN measurement, initial spoilage was showed within 2 or 3 weeks in SMF soaked with brine including extracts of green tea, herb and ginger at 5$^{\circ}C$. In case of adding chitosan and oligosaccarides to the solution mentioned above, initial spoilage was found from 4 to 7 weeks, oxidation was reduced remarkably and SMF stored at -20$^{\circ}C$ maintained the freshness during 80 days. Viable cell counts were reached to 108 for 3 weeks storage at 5 and 0$^{\circ}C$. But no change of viable cell counts was founded at -20$^{\circ}C$. The shelf-lifes of SMF according to 5, 0 and -20$^{\circ}C$storage temperatures were 2 to 3, 4 to 7 weeks and about 3 months, respectively.

• Food Science and Preservation
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• v.16 no.6
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• pp.804-809
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• 2009

Recently, many Koreans have started to consume aged kimchi fermented long-term at low temperatures. In the present study, the effect of low temperature ($5^{\circ}C$) on pH, titratable acidity (TA), organic acid level, viable microbial cell count, amino acid concentration, and polygalacturonase activity (PG) during long-term fermentation (46 weeks) of kimchi, were evaluated. After 10 weeks of fermentation, kimchi had a pH of 4.1 and a TA of 1.0%, respectively after 46 weeks fermentation, these values were 3.9 and 1.3%, respectively. Lactic acid, the ratio of lactic acid to acetic acid, and the ratio of Lactobacillus species/Leuconostoc species in kimchi increased as fermentation progressed from 10 weeks to 46 weeks. However, total viable cell counts of aerobic bacteria, yeasts, Lactobacillus species, and Leuconostoc species, free amino acid levels, and PG decreased as the fermentation period was extended from 10 weeks to 46 weeks.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.189-196
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• 2015

The aim of this study was to manufacture functional high protein fermented beverage, using whey protein concentrate (WPC) and Lactobacillus plantarum DK211 isolated from kimchi, and to evaluate the physicochemical, functional, and sensory properties of the resulting product. The fermented whey beverage (FWB) was formulated with whey protein concentrate 80 (WPC 80), skim milk powder, and sucrose; and fermented with Lactobacillus plantarum DK211 as single, or mixed with Lactococcus lactis R704, a commercial starter culture. The pH, titratable acidity, and viable cell counts during fermentation and storage were evaluated. It was found that the mixed culture showed faster acid development than the single culture. The resulting FWB had high protein (9%) and low fat content (0.2%). Increased viscosity, and antioxidant and antimicrobial activity were observed after fermentation. A viable cell count of 10⁹ CFU/mL in FWB was achieved within 10 h fermentation, and it remained throughout storage at 15℃ for 28 d. Sensory analysis was also conducted, and compared to that of a commercial protein drink. The sensory scores of FWB were similar to those of the commercial protein drink in most attributes, except sourness. The sourness was highly related with the high lactic acid content produced during fermentation. The results showed that WPC and vegetable origin lactic acid bacteria isolated from kimchi might be used for the development of a high protein fermented beverage, with improved functionality and organoleptic properties.

• Journal of Food Hygiene and Safety
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• v.14 no.4
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• pp.352-357
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• 1999

Changes in titratable acidity, viable cells and sensory properties of curd yogurt during lactic fermentation in milk added with mugwort extract have been studied. Milk added with 5%, 10％, 15％ or 20% of mugwort extract was fermented with single or mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus for 24 hours. Addition of mugwort extract markedly stimulated the acid production and propagation of lactic acid bacteria. Among the organism tested, the mixed culture of Lactobacillus bulgaricus and Streptococcus thermophilus produced the highest amount of acid, and Lactobacillus bulgaricus showed the highest number of viable cell counts. Sensory property of curd yogurt added with mugwort extract was evaluated as better than reference sample(milk yogurt). The sample prepared by fermenting milk containing mugwort extract at 5% level with Lactobacillus bulgaricus showed the most favorite characteristics.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.444-448
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• 2002

A $CaCO_3$-alginate beads system was developed for high cell density cultivation of Bifidobacterium longum and the cost-effective media were also screened. In batch process with $CaCO_3$, beads, two strains of B. longum showed both the highest viable cells and optical density in TPY medium, resulting in maximum optical density and viable cell counts of 12.40, $2.22{\times}10^10$ cfu/ml for B. longum ATCC 15707 and 13.71, $3.93{\times}10^10$ cfu/ml for B. longum HLC 3742. Released size distribution, according to $CaCO_3$-alginate bead size preparation, was smaller than others. These results were also examined by observing their morphology. The skim milk-based medium was most adequate to cultivate B. longum as the cheapest medium, and $10\%$ skim milk supplemented with $2\%$ glucose and $1\%$ yeast extract was a suitable medium, supporting the growth to $5.57{\times}10^10$ cfu/ml for ATCC 15707 and $6.82{\times}10^9$ cfu/ml for HLC 3742. During the long-term storage at $4^{\circ}C\;and\;-20{\circ}C$, B. longum cultivated with $CaCO_3$ beads had the highest stability. Consequently, $CaCO_3$-alginate beads buffer was found to be useful not only to cultivate B. longum but also to preserve cultures.

• Journal of Animal Science and Technology
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• v.44 no.4
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• pp.491-498
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• 2002

The inhibitory effect of lactobacilli and bifidobacteria on the growth of typical intestinal pathogens, Escherichia coli and Salmonella typhimurium was studied. The degree of inhibition was measured by well disc assay and turbidimetry method. The strains which showed the higher antimicrobial activity were L. acidophilus La-5, L. acidophilus NCFM, L. casei Lc-01 on the average by using two different methods. The associative cultures were performed with selected 3 lactobacilli and 2 enteropathogens E. coli and S. typhimurium, respectively. Inhibition of pathogen began at 9hr after culturing so that viable counts was decreased rapidly. After 30hr incubation, there were no viable pathogens from the mixed culture. Under this experimental condition, the antimicrobial activity of lactic acid bacteria was not due to pH alone and supposed to different to the strains.

• Fisheries and Aquatic Sciences
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• v.17 no.2
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• pp.197-201
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• 2014

This study was performed to identify and assess food hazards during dry laver processing. Samples including raw materials, intermediates, and finished products during dried-laver processing were collected from seven dried-laver processing facilities, and microbial analyses were conducted. Microbial levels such as total coliforms and total viable cell count (TVC) increased as the processing steps progressed. TVC and total coliforms ranged from <30 to $9.1{\times}10^7$ CFU/g and <18 to 27,600 MPN/100 g for intermediates and finished products obtained during dried-laver processing, respectively. However, no fecal coliform was detected in the samples. Additionally, food-borne bacteria including Bacillus cereus, Listeria monocytogenes, Salmonella sp., Staphylococcus aureus, and Vibrio parahaemolyticus were not identified in finished products. For heavy metal content, arsenic ranged from 30.18 to 39.05 mg/kg, mercury from 0.005 to 0.009 mg/kg, and cadmium from 0.076 to 0.318 mg/kg dry mass in all finished products. However, lead was not detected in samples tested in this study. In conclusion, dried-laver products were safe based on the levels of food-borne bacteria and heavy metal contents. However, it is important to reduce total viable cell counts and total coliforms during dried-laver processing.