• Food Science and Preservation
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• v.24 no.8
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• pp.1067-1078
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• 2017

This study was carried out to investigate the physicochemical and antioxidant properties of fermented milk with addition of hot water extract of Cordyceps militaris grown upon Tenebrio molitor. The general components of Cordyceps militaris grown upon Tenebrio molitor are moisture 10.85%, crude protein 18.44%, crude fat 2.07%, crude ash 5.46%. The DPPH radical scavenging activities of different solvents were the highest (74.81 EDA%) with hot water extract sample. The acidity of fermented milk was high with increasing amount of extracts. The pH of fermented milk reached 4.60-4.66 after 4 h of fermentation, and the number of lactic acid bacteria was highest (11.70 log CFU/mL) with 1% fermented milk. The moisture content of fermented milk showed no significant difference. In addition, contents of crude protein were not significantly different according to addition amount. Regarding Hunter's color values, L value decreased as the amount of extract increased, whereas a value and b value increased. The content of free amino acid increased with increasing amount of extract. The DPPH free radical scavenging ability and ABTS free radical scavenging ability of fermented milk were significantly different as the addition amount of extract increased. In the sensory evaluation, fermented milk containing 1% of extract showed the highest preference.

• Korean Journal of Food Science and Technology
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• v.45 no.5
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• pp.571-577
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• 2013

Our aim was to ferment soymilk using lactic acid bacteria that showed protease activity and to optimize the condition for fermentation. In total, 108 strains of protease-producing lactic acid bacteria were isolated from various fermented foods such as kimchi and jeotgal, and among them, 29 strains displaying the highest protease activity were selected for further study. From these 29 strains, strain MK1, whose protease activity was 126 $mU/mL{\cdot}min$, was selected as the optimal fermentation strain owing to its high ability to digest soymilk protein. It was henceforth labeled as Lactobacillus paracasei MK1. The optimum conditions for the fermentation of soymilk by using L. paracasei MK1 were determined to be as follows: 30 h of fermentation time at a temperature of $30^{\circ}C$, and at a pH of 6.0 in the initial growth medium.

• Food Science of Animal Resources
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• v.37 no.5
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• pp.735-742
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• 2017

This study was conducted to isolate and characterize Paenibacillus sp. MBT213 possessing ${\beta}$-glucosidase activity from raw milk, and examine the enzymatic capacity on the hydrolysis of a major ginsenoside ($Rb_1$). Strain MBT213 was found to have a high hydrolytic ability on ginsenoside $Rb_1$ by Esculin Iron Agar test. 16S rDNA analysis revealed that MBT213 was Paenibacillu sp. Crude enzyme of MBT213 strain exhibited high conversion capacity on ginsenoside $Rb_1$ into ginsenoside Rd proven by TLC and HPLC analyses. The API ZYM kit confirmed that Paenibacillu sp. MBT213 exerted higher ${\beta}$-glucosidase and ${\beta}$-galactosidase activity than other strains. Optimum pH and temperature for crude enzyme were found at 7.0 and $35^{\circ}C$ in hydrolysis of ginsenoside $Rb_1$. After 10 d of optimal reaction conditions for the crude enzyme, ginsenoside $Rb_1$ fully converted to ginsenoside Rd. Ginseng roots (20%) were fermented for 14 d, and analyzed by HPLC showed that amount of ginsenoside $Rb_1$ significantly decreased, while that of ginsenoside Rd was significantly increased. The study confirmed that the ${\beta}$-glucosidase produced by Paenibacillus sp. MBT213 can hydrolyze the major ginsenoside $Rb_1$ and convert to Rd during fermentation of the ginseng. The ${\beta}$-glucosidase activity of this novel Paenibacillus sp. MBT213 strain may be utilized in development of variety of health foods, dairy foods and pharmaceutical products.

• Food Science of Animal Resources
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• v.26 no.4
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• pp.511-516
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• 2006

The objectives of this study was to compare the probiotic characteristics of lactic acid bacteria (LAB) for their ability to assimilate cholesterol, production of bacteriocin, inhibition of angiotensin I-converting enzyme (ACE), and viability under artificial gastrointestinal fluids. Among tested lactic acid bacteria, L167 strain exhibited the highest ACE inhibitory activity (58.75%). The production of ACE inhibitory peptide derived from fermented milk by L167 strain started at the beginning of stationary phase with maximum activity occurring late of the stationary phase. The highest ACE inhibitory activity was observed at 20 h in 10% skim milk medium. L155 strain exhibited cholesterol assimilation activity compared with probiotic strains such as Lactobacillus acidophilus ATCC 43121. With addition of bacteriocin culture, viable cells of Staphylococcus aureus in fermented sausage were slightly decreased during storage. Among selected strains of LAB, 3 strains weve identified as L. plantarum (L155, L165, L167), and two strains were identified as Pediococcus damnosus (L12) and L. paracasei ssp. paracasei (P113) by use of API carbohydrate fermentation pattern and physiological tests.

• Food Science of Animal Resources
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• v.32 no.5
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• pp.635-643
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• 2012

As an appraisal for the application of a new starter culture, more than 200 lactic acid bacteria strains were isolated from raw milk and healthy human feces. The strains showing excellent growth and acid production ability in 10% skim milk media were selected and identified as Lactobacillus casei based on the results of their API carbohydrate fermentation patterns, as well as 16S rDNA sequence analysis. To assess the effect of L. casei strains on irritable bowel disease (IBD), the inhibitory effect of the selected strains against the nitric oxide (NO) production of lipopolysaccharide (LPS)-stimulated RAW 264.7 cells was measured. Among the tested L. casei strains, L. casei MCL was observed to have the greatest NO inhibitory activity. Additionally, L. casei MCL was found to inhibit mRNA expression of pro-inflammatory cytokines (interleukin-$1{\beta}$, IL-6, TNF-${\alpha}$), as well as cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) involved in pathophysiologic processes such as inflammation. The mRNA expression of anti-inflammatory cytokines, including IL-10 and transforming growth factor-$1{\beta}$ (TGF-${\beta}$) of L. casei MCL, was confirmed using quantitative real-time PCR. In conclusion, L. casei MCL showed decreases in the expression of pro-inflammatory cytokines and up-regulated expression of the anti-inflammatory cytokine.

• Korean Journal of Food Science and Technology
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• v.42 no.2
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• pp.142-146
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• 2010

Relatively large amounts of GABA can be produced by the fermentation of rice bran. Therefore, this study was conducted to investigate the effects of GABA on the secretion of melatonin and serotonin for the development of a sleep inductive compound. The secretion levels of melatonin and serotonin from mice were found to be $3.425{\pm}0.182\;pg/mL$ and $5.37{\pm}0.963\;ng/mL$, respectively, in response to feeding 120 mg/mL of GABA while they were $2.607{\pm}0.41\;pg/mL$ in the control. The secretion of both melatonin and serotonin was increased up to the 13.51% and 34.99%, respectively, when compared to the negative control. However, the feeding of milk alone did not have a great effect on the melatonin and serotonin secretions. Conversely, feeding of milk with GABA enhanced the secretion of serotonin. The amounts of both melatonin and serotonin secreted increased with respect to the increase in GABA concentrations during feeding. Interestingly, the induction level of melatonin was relatively higher than that of serotonin in response to feeding 120 mg/mL of GABA. This is the first study to report that GABA has an ability to induce sleep related hormones in mice; therefore, it has the potential for use as a natural sleep aid.

• Microbiology and Biotechnology Letters
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• v.31 no.4
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• pp.348-354
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• 2003

This study was conducted to confirm the availability of lactic acid bacteria as probiotics haying inhibitory effects to cancer cell line. Five lactic acid bacteria showing anti-cancer activity were compared by acid tolerance, bile tolerance, antibiotics resistance, milk fermentation, stability, and cell adherence activity to colon epithelial cell. The results obtained are as follows : In acid tolerance, all strains did not have a resistance below pH 3.0 and 3.5 except Lactobacillus plantarum KCTC3099. In antibiotics resistance, Lactococcus lactis and L. plantarum KCTC3099 were resistant to cotrimoxazol (128 mg/1), and Bifidobacterium adolescentis Maeil-K8 and B. infantis Maeil-K9 were resistant to doxycylin and gentamycin (4 mg/1). In case of cell adherence ability to Caco-2 cell, B. infantis Maeil-K9 was found to be superior to others as 3.1%, while the others were less than 0.5%. When the strains were cultured to milk base, viable counts of the strains tested increased more 1 log cycle than inoculation, but acid production was very low except L. plantarum KCTC3099. Also, L. plantarum KCTC3099, B. adolescentis Maeil-K8, and B. infantis Maeil-K9 were stable in fermented milk base during storage. In conclusion, L. plantarum KCTC3099 and B. infantis Maeil-K9 were confirmed to be superior for the availability as probiotics.

• Food Science and Preservation
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• v.24 no.5
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• pp.707-713
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• 2017

The objective of this study was to select yogurt starter from Korean traditional fermented foods. The 2 strains (KM24, KM32) among 50 strains of isolated lactic acid bacteria selected as starter based on milk clotting ability, antimicrobial activity against various pathogens, tolerance in artificial gastric and bile juice and growth in 10 % skimmed milk. The strains were identified as Lacobacillus plantarum (KM32) and Pediococcus pentosacesus (KM24) by 16S rRNA gene sequencing. Viable cell number of yogurt fermented with mixed strains (KM24 and KM32) was 9.66 log CFU/mL after fermentation for 48 h and maintained $10^9CFU/mL$ during fermentation for 72 h at $37^{\circ}C$. The pH and titratable acidity of mixed cultured yogurt were 4.25% and 0.83% after fermentation for 48 h at $37^{\circ}C$, respectively. The physico-chemical characteristics of mixed cultured yogurt after fermentation for 48 h were $38.45{\mu}g/mL$ (polyphenol content), 48.57% (DPPH radical scavenging activity) and 465.40 cp (viscosity), respectively. The mixed cultured yogurt maintained $10^9CFU/mL$ of lactic acid bacteria during storage 10 days at $4^{\circ}C$. The viable cell number of yogurt prepared with mixed culture(KM32+KM24) maintained higher and than that of control (L. casei) during storage. These results indicated the potential use of selected strains (KM32+KM24) isolated from kimchi as a yogurt starter with strong acid tolerance and probiotics properties.

• Korean Journal of Food Science and Technology
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• v.35 no.6
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• pp.1244-1247
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• 2003

The purpose of this study was to isolate lactic acid bacteria that produced L(+) lactic acid from infant feces. Thirteen colonies were isolated with a MRS-plate containing 0.5% $CaCO_3$ to determine their ability to produce lactic acid. Based on their lactic acid production, 10 strains of Lactobacillus were identified to assess the ratio of lactate isomer using HPLC. A strain producing L-lactic acid was identified as Lactobacillus acidophilus, using API carbohydrate fermentation patterns and physiological tests, and named KY1909. The strain exhibited good acid tolerance in an artificial gastric juice as well as high bile resistance in MRS containing 0.5% bile acids. L. acidophilus KY1909 produced D(-) and L(+) lactic acid at a ratio of 6 : 94; whereas commercial strains of Lactobacillus acidophilus produced D(-) and L(+) lactic acid at a ratio of 1 : 1. These results demonstrate the L. acidophilus KY1909 can be utilized in fermented milk products and dietary supplements as a probiotic culture.

• Microbiology and Biotechnology Letters
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• v.48 no.4
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• pp.455-462
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• 2020

Leuconostoc mesenteroides CJNU 0705 was isolated from a breast milk sample and identified by 16S rRNA gene sequencing and confirmed by its ability to produce dextran from tryptic soy agar plates supplemented with 2% sucrose. This strain can absorb various heavy metals including lead (Pb) and cadmium (Cd) which are both found in fine dust and have been shown to be harmful to human skin. In addition, Leu. mesenteroides CJNU 0705 has demonstrated antimicrobial activity against Propionibacterium acnes, the primary causative agent of acne. Given these traits it was natural to evaluate the use of this strain in the fermentation of several natural extracts from green tea, carrot, annual wormwood, parsley, broccoli, and corn silk, which are known to improve skin health, to see if it could increase their dextran content when supplemented with no sucrose, 2% sucrose, or 2% sucrose and 3% yeast extract. The extracts supplemented with both yeast and sucrose were found to produce the most dextran, which was confirmed by the scanning electron microscope (SEM) images. These results suggest that Leu. mesenteroides CJNU 0705 and its fermented natural extracts could be used as functional materials for improving human skin health.