• Korean Journal of Food Science and Technology
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• v.46 no.5
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• pp.556-565
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• 2014

In this study, we evaluated changes in physicochemical properties, total phenol and isoflavone contents, and antioxidant activity during soymilk fermentation by a potential probiotic Lactobacillus plantarum P1201. The P1201 strain showed survival rates of 58.14% and 62.22% after 4 h exposure to acid and artificial gastric acid conditions (pH 2.5), respectively. The optimal conditions for soy-yogurt fermentation by L. plantarum were determined to be as follows: temperature of $35^{\circ}C$, seed volume of 5.0%, and sucrose content of 10.0%. The total phenol and isoflavone contents and antioxidant activity were higher in soy-powder milk (SPM) yogurt than soymilk yogurt. In particular, the highest levels of isoflavone-aglycones, such as daidzein, glycitein, and genistein (91.50, 12.34, and $61.39{\mu}g/g$, respectively), were observed after 48 h of SPM fermentation. Thus, these results suggest that the soy-yogurt extract could be used as a potential source of natural antioxidants in food.

• Korean Journal of Microbiology
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• v.52 no.2
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• pp.202-211
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• 2016

This study evaluated the changes of phytoestrogen contents and antioxidant activities of soybean-powder milk (SPM) prepared from yellow soybean during fermentation with Lactobacillus plantarum P1201. In consequence, the levels of total phenolic and isoflavone-aglycone contents, ABTS and DPPH radical-scavenging activities, and FRAP assay values increased, while isoflavone-glycoside contents decreased during fermentation. The highest levels of daidzein, glycitein, and genistein were present in the Daepung SPM at concentrations of 177.92, 20.64, and $106.14{\mu}g/g$, respectively after 60 h of fermentation. Moreover, Daepung SPM showed the highest DPPH radical-scavenging activity of 48.54%, an ABTS radical-scavenging activity of 99.25%, and a FRAP assay value of 0.84 at the end of fermentation. The fermented Daepung SPM possessed highest isoflavone aglycone contents and antioxidant activities, which can be utilized for the development of functional foods.

• Korean Journal of Microbiology
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• v.51 no.3
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• pp.231-240
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• 2015

In this study, a total of 16 conjugated linoleic acid (CLA) producing lactic acid bacteria (LAB) were isolated from fermented foods. Among those strains, the S48 and P1201 strains were capable of producing higher CLA contents than other LABs. The two strains were classified as Lactobacillus plantarum based on morphological, physiological, chemotaxonomic, and molecular-genetic properties. The survival rates of these strain appeared to be 59.57% and 62.22% under artificial gastric conditions after 4 h at pH 2.5, respectively. These strains produced the cis-9, trans-11, and trans-10, cis-12 CLA isomers from 8% skim milk medium supplemented with the different free LA concentration at $37^{\circ}C$ for 48 h and the production of two CLA isomers constantly increased in the growth until 48 h of incubation. After 48 h of fermentation, the levels of CLA appeared highest in steamed soy-powder milk than fresh and roasted soy-powder milks. In particular, the CLA contents were produced $183.57{\mu}g/ml$ and $198.72{\mu}g/ml$ from steamed soy-powder milk after fermentation (48 h) with S48 and P1201 strains, respectively.

• Journal of agriculture & life science
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• v.50 no.4
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• pp.157-167
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• 2016

The changes of total phenolic and isoflavone contents and antioxidant activities in of brown soymilk fermented by Lactobacillus plantarum P1201 were investigated. The brown soymilk proliferated the cell growth and reached about 11.55log cfu/g after fermentation for 60hr, while pH and titratable acidity ranged from 6.25 to 4.03 and 0.18% to 1.03%, respectively. The total phenolic contents of brown soymilk slightly increased from 2.87mg/g to 2.98mg/g after fermentation for 60hr. The levels of isoflavone-glycosides and -malonylglycosides decreased, while the isoflavone-aglycone contents increased during fermentation of brown soymilk. In particular, the isoflavone contents was 38.30㎍/g, but increased the highest value of 84.31㎍/g after fermentation for 60hr. After then, it was slightly decreased after 60hr of fermentation. In addition, the levels of daidzein, glycitein and genistein among isoflavone aglycones were 24.12㎍/g, 25.25㎍/g and 24.71 ㎍/g, after fermentation for 36hr. The DPPH and ABTS radical scavenging activities and FRAP assay showed to be slightly increased during lactic acid fermentation of brown soymilk.

• Journal of Microbiology and Biotechnology
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• v.16 no.8
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• pp.1201-1209
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• 2006

The purpose of this study was to isolate probiotic lactic acid bacteria (LAB) that produce bile salt hydrolase (BSH), and to evaluate its effects on serum cholesterol level. One-hundred-twenty bacterial colonies were initially isolated from human feces, and five strains were selected after screening based on their resistance to acids, tolerance against bile salts, and inhibitory activity on Escherichia coli. The Lactobacillus plantarum strain with the highest level of BSH activity was identified using 16S rRNA sequences, and was named L. plantarum CK 102. L. plantarum CK 102 at a level of 1.36$\times$10$^8$cfu/ml survived in pH 2 buffer for 6 h and exhibited excellent tolerance for bile salt. Coculturing the strain with E. coli in MRS broth resulted in strong inhibition against growth of E. coli at 18 h. Furthermore, the potential effect of CK 102 on serum cholesterol level was evaluated in rats. Thirty-two rats [Sprague-Dawley (SD) male, 129$\pm$l g, 5 weeks old] were divided into four groups of eight each. For six weeks, Group 1 was fed a normal diet (negative control); Group 2 was fed a cholesterol-enriched diet (positive control); Group 3 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 1.0$\times$10$^7$cfu/ml; and Group 4 was fed a cholesterol-enriched diet plus L. plantarum CK 102 at 5.0$\times$10$^7$cfu/ml. Blood samples were collected, serum lipids were analyzed, and weights of the organs were measured. Total blood cholesterol level, triglyceride, LDL-cholesterol, and free-cholesterol values were lower in rats that were fed 1. plantarum CK 102 than in those not fed L. plantarum CK 102. This cholesterol lowering effect implies that L. plantarum CK 102 could be utilized as an additive for health-assistance foods. In conclusion, these results suggest that the 1. plantarum CK 102 isolated could be used commercially as a probiotic.