• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.472-479
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• 2002

The antimicrobial effects of metabolites from isolated strains from feces of Korean newborn baby and from Dongchimi against six food-borne microorganisms, and characteristics of the metabolites were investigated.. The metabolites from isolated strains adjusted pH to 3.5, 4.0, and 4.5 showed strong growth inhibition against S. Typhimurium, and S. Enteritidis. The metabolites has kept its inhibition activities to the pathogens after catalase, trypsin or pepsin treatment. In addition, antimicrobial activity of metabolites was not decreased by heat treatment at $121^{\circ}C$ for 15 min. D2 and F35-2 strains were confirmed homofermentative and F20-3 was heterofermentative bacteria identified by final organic acid and gas production. The amount of lactic acid produced by D2 and F35-2 strains after 24 h of incubation was 1.84 and 1.85% respectively, but F20-3 strain produced acetic acid (0.22%) and lactic acid (0.91%).

• Korean Journal of Food Science and Technology
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• v.32 no.1
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• pp.192-199
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• 2000

Lactic acid bacteria (LAB) fermented food was prepared from milk or egg white powder (EWP) and added with five kinds of freeze drying protectant (FDP). Effects of FDP on growth and acid production of LAB were investigated. Effects of FDP on organoleptic properties of LAB fermented food were also studied. (1) Some of FDPs showed protective effect against damage to Lactobacillus acidophilus in LAB fermented food during freeze drying, while FDP did not show any protective effect against damage to L. acidophilus during freezing. This protective effect differed with substrate and concentration of FDP (2) Optimum concentration of Tween 80 and ascorbate added to milk sample was 0.2 % (W/V) and 1 %(W/V), respectively. Optimum concentration of raffinose and ascorbate added to EWP sample was 3 %(W/V) and 1 %(W/V), respectively (3) Among FDPs added to L. casei fermented food, raffinose and ascorbate added to EWP sample showed FDP effect. Among FDPs added to L. delbrueckii fermented food, raffinose added to EWP sample showed FDP effect. (4) Samples added with MSG showed MSG taste. Milk sample added with ascorbate showed slightly more acid taste than reference sample, while taste of EWP sample added with ascobate did not differ with reference sample. Tween 80 added to milk sample or EWP sample improved texture of LAB fermented food.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.7
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• pp.1180-1185
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• 2004

This study was conducted to investigate the optimum conditions for the medium composition after isolating and identifying yeast and lactic acid bacteria from sourdough. It was found that the best quality lactic acid bacterium with acid product and flavor was identified as Leuconostoc species among isolated 115 lactic acid bacteria, the best Quality yeast with good fermentation and flavor was identified as Saccharomyces species among isolated 8 yeast. While the microbial growth with glucose or sucrose as sugar source was good, it was, selected that sucrose which is using commercially is better than glucose. The growth of lactic acid bacterium ; was good with 1％ added sucrose whereas yeast needed more growth. Additionally, the medium for the optimum 1 growth of the yeast was composed of 0.5％ wheat flour, 0.5％ peptone and 3％ sucrose, whereas lactic acid bacterium was composed of 0.5％ wheat flour and 1％ sucrose without peptone.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.183-191
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• 1990

Soy milk prepared from soy protein concentrate was added with each of four types of milk products. Acid production and growth of five species of lactic acid bacteria(LAB) in soy milk and sensory property of soy yogurt were investigated. Acid production by LAB increased in proportion to concentration of milk products added to soy milk. Among the four milk products tested, whey powder or skim milk powder stimulated acid production by LAB more than whole milk powder or modified milk powder. Stimulating effect by whey powder on acid production by LAB was greater than other milk products at low concentration. Acid production by LAB in soy milk added with glucose or milk products significantly increased during fermentation. Sensory property of soy yogurt added with whole milk powder or skim milk powder was better than that of reference (soy yogurt added with glucose) while sensory property of soy yogurt added with whey powder or modified milk powder was Inferior to that of reference.

• Microbiology and Biotechnology Letters
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• v.31 no.2
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• pp.191-196
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• 2003

This study was carried out to investigate the isolation, identification, and antibacterial activity of lactic acid bacteria related to kimchi fermentation. Diluted kimchi soup was plated on the MRS agar media with CaCO$_3$ and incubated at $25^{\circ}C$ for 2 days. A total of 27 strains of lactic acid bacteria from various indigenous, spontaneously fermented vegetables (kimchi) were isolated. Combined methods of Bergey's manual of systematic bacteriology, BPB media analysis and 16S rDNA sequence analysis were applied for identification, however, their results did not coincide in several cases. Isolated lactic acid bacteria could be classified by the 16S rDNA sequence analysis as Leuconostoc mesenteriodes, Leu. carnosum, Lactobacillus curvatus, Lac. pentosus, Weisselia kimchi, W. cibaria, and Pediococcus pentosaceus. Leu. carnosum has not been reported in kimchi lactic acid bacteria. In addition, antibacterial activities of the isolates were tested with Bacillus subtilis, Escherichia coli, Salmonella enteritidis, S. paratyphica, S. typhi, Staphylococcus aureus, Shigella boydii, and S. sonnei. Some of isolates showed significant antibacterial activities to those pathogens.

• Microbiology and Biotechnology Letters
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• v.30 no.2
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• pp.116-122
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• 2002

The partial 165 rDNA sequences of 6 lactic acid bacterial strains isolated from Kimchi were determined. Two strains were Leuconostoc mesenteroides and the rest were incorrectly classified and turned out to be Lactobacillus. As the case of dairy lactic acid bacteria, the strains isolated from Kimchi also had cell-envelope proteinase (CEP) activity. As the result of partial CEP gene amplification with CEP-specific primers, the expected 1.2-kb amplificate was obtained not from Leu. mesenteroides but from Lactobacillus strains. The deduced amino acid sequence of PCR product amplified from the genomic DNA of Lactobacillus pentosus KFR1821 showed 95％ and 92％ homology with those of PrtPs from Lactococcus lactis subsp. cremoris and Lactobacillus paracasei subsp. paracasei, respectively. The PCR amplificate was used as a probe and the result of Southern hybridization illuminated the location of CEP gene in chromosomal DNA of Lb. pentosus KFR1821.

• Korean journal of food and cookery science
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• v.7 no.2
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• pp.89-95
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• 1991

The effects of lactic acid bacteria on the chemical and microbial changes of fermented kimchi at various temperatures were studied. Kimchi was homogenized and was sterilized by ultra violet (UV), then Lactobacillus plantarum, Leuconostoc mesenteroides, Pediococous acidilactici, Lactobacillus brevis and the mixture of these bacteria inoculated on sterilized kimchi, respectively. The measurement of alcohol by gas chromatography, and changes of sugar content and total viable count were investigated and palatability test was carried while inoculated kimchi was fermented at $30^{\circ}C$, $21^{\circ}C$ and $7^{\circ}C$. Ethyl alcohol was detected by GC in sample I (original Kimchi homogenate), III(inoculated Leu. mesenteroides), V(inoculated with Lac. brevis), then especially, more content were detected at $14^{\circ}C$. Sugar content reduced in accordance with fermentation proceeding. Total viable count increased at early fermentation stage, but thereafter decreased slowly. In the result of palatability test, sample I was the highest at all temperatures, sample III and IV (inoculated with mixed lactic acid bacteria) was the following in that kimchi odor and taste and the temperature.

• Korean Journal of Food Science and Technology
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• v.25 no.6
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• pp.747-752
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• 1993

A curd yogurt was prepared from milk added with skim milk powder or four kinds of starch such as rice starch, wheat starch, corn starch and potato starch. The effects of starch addition at 2%(w/v) level on acid production by lactic acid bacteria in milk was investigated. The effects of starch addition on quality of curd yogurt in terms of apparent viscosity, sensory property and volatile aroma compounds were also examined. Addition of starch markedly stimulated the acid production by lactic acid bacteria. Among four organisms tested, Lactobacillus jugurti produced the highest amount of acid. Apparent viscosity of curd yogurt added with starch was significantly higher than that of control. Curd yogurt fermented with L. jugurti showed pseudoplastic and thixotropic characteristics. Sensory property of curd yogurt added with corn starch or rice starch was evaluated as slightly better than reference sample, but that with potato starch was evaluated as the worst among all samples. Acetaldehyde, acetone, ethanol and butanol were detected by gas chromatographic analysis.

• Korean Journal of Food Science and Technology
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• v.24 no.5
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• pp.470-476
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• 1992

The curd yogurt was prepared from milk added with skim milk powder or three Tongil rices of different storage period. The effect of storage period of rice on acid production by lactic acid bacteria in milk containing rice of 2%(w/v) was investigated. The effect of storage period of rice on quality of curd yogurt(sensory property, viscosity and keeping quality) was also examined. Addition of rice stimulated acid production by lactic acid bacteria more than control(milk yogurt). Storage period of rice did not significantly affect acid production by lactic acid bacteria though stimulating effect of rice on acid production was slightly different among species. Sensory property of curd yogurt added with rice was not significantly affected by storage period of rice. Apparent viscosity of curd yogurt added with rice increased in proportion to storage period of rice. Curd yogurt showed characteristics of thixotropic flow. When curd yogurt added with rice was kept at $5^{\circ}C$ for 15 days, its keeping quality was relatively good and was not markedly affected by storage period of rice.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.612-617
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• 1995

Changes in titratable acidity, pH, viable cells, sensory properties and volatile aroma compounds of yogurt during lactic fermentation in milk added with egg white powder (EWP) have been studied. Milk added with 1% or 2% (W/V) of EWP was fermented with Lactobacillus acidophilus for 30 hr. Acidity of milk added with EAT increased gradually during lactic fermentation for 30 hr, pH dropped gradually and number of viable cells increased and reached stationary phase at about 9 hr. Addition of EWP significantly stimulated acid production by lactic acid bacteria and stimulating effect of 2% EWP addition on acid production was slightly higher than that of 1% EWP addition. Sensory evaluation showed that optimum fermentation time of yogurt prepared from milk added with 2% of EWP was about 15 hr. Gas chromatographic analysis showed that the amount of acetone and butanol decreased gradually and that of ethanol increased until 30 hr. Diacetyl and acetoin were first detected after 6hr and 9hr, respectively, and then increased until 30 hr.