• Korean Journal of Food Science and Technology
• /
• v.8 no.2
• /
• pp.85-89
• /
• 1976

The separation and determination of dicarbonyls such as diacetyl, methylglyoxal and triose reductone in their mixed aqueous solution were carried out by means of gas chromatography with transformation of these compounds into quinoxaline derivatives with o-phenylenediamine. A column used for this experiment was consisted of Celite 545 (80-100 mesh) coated with 5% Silicon Gum SE-30. The column temperature was $180^{\circ}C$. It is desirable that this approach will be applicable to dicabonyl study in gas chromatographic determination.

• Food Science and Biotechnology
• /
• v.18 no.3
• /
• pp.761-765
• /
• 2009

The effects of probiotic bacteria on the functional properties of squid by-products were investigated during fermentation. Bifidobacterium longum, Lactobacillus acidophilus, Lactobacillus brevis, Lactobacillus casei, Lactobacillus paracasei, Lactobacillus rhamnosus, and Pediococcus acidilactici were used to ferment the squid by-products for 96 hr at $37^{\circ}C$. The numbers of all probiotics increased to $10^7-10^8$ CFU/g after 96 hr fermentation. No substantial pH changes were observed. L. rhamnosus and P. acidilactici showed the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities. Interleukin-6 (IL-6) and tumor necrosis $factor-{\alpha}$ ($TNF-{\alpha}$) secreted from B cells increased after adding the extracts of probiotic-fermented squid by-products. The human NK cells were grown well in the B cell-growing broth cultured with the extracts of squid by-products fermented by L. rhamnosus and P. acidilactici. Trimethylamine (TMA) and dimethylamine (DMA) contents were significantly decreased after probiotic-fermentation. Therefore, L. rhamnosus GG and P. acidilactici can be used for the fermentation of squid by-products and their use would provide benefits in functional food products.

• Food Science and Biotechnology
• /
• v.16 no.1
• /
• pp.78-82
• /
• 2007

Since germanium has been shown to be beneficial for the treatment of diseases such as cancer and rheumatic arthritis, we developed an adapted process of bio-germanium preparation using inorganic germanium. In the present study we determined the optimal conditions for culturing yeast Saccharomyces cerevisiae (KCTC-1199), and the best concentrations of inorganic germanium for the adaptation process. The resulting method was successful at producing high quantities of germanium yeasts. The following are the culture conditions that obtained the highest level of productivity: an inorganic germanium concentration of 3,000-5,000 ppm, a pH of 6.5, a temperature of $35^{\circ}C$, and 20 hr of incubation time. In addition to this high-yield quantity study, we observed the acute oral toxicity of mice treated with Geranti Bio-Ge $Yeast^{(R)}$. We found no changes in body weight, or in the mortality between the control groups and the bio-germanium yeast group. There were also no digestive problems such as diarrhea that occurred in either group.

• Journal of the Korean Society of Food Culture
• /
• v.30 no.6
• /
• pp.757-765
• /
• 2015

The objective of this study was to determine the quality characteristics of fermenting mash and pasteurized ginseng Makgeolli added with different concentrations of ginseng powder. Total aerobic bacteria and lactic acid bacteria counts of mash added with 0, 1, 2, and 4% ginseng powder during 4 days of fermentation significantly increased, whereas yeast count decreased. Viable cell count remarkably decreased after pasteurization. Pasteurized 4% ginseng Makgeolli (4.30) showed a higher pH than 0, 1, and 2 % ginseng Makgeolli (4.09, 4.08, and 4.06, respectively) after 15 days of aging. After aging, amylase activity of pasteurized Makgeolli decreased, and 0% and 1% ginseng Makgeolli (22.35, $21.55^{\circ}Brix$) showed higher Brix content than 4% ginseng Makgeolli ($20.15^{\circ}Brix$). Before aging, alcohol contents of 0, 1, 2, and 4% pasteurized ginseng Makgeolli were 5.80, 5.50, 5.20, and 5.10%, respectively. After 15 days of aging, 0% ginseng Makgeolli (7.00) showed higher alcohol content than 1, 2, and 4% ginseng Makgeolli (5.90, 5.80, and 5.60%, respectively). The results of the sensory evaluation show that 2% ginseng Makgeolli after 3 days of aging at $4^{\circ}C$ had the highest scores for taste (5.19), flavor (5.04), and overall acceptability (5.22) among the samples.

• Journal of the Korean Society of Food Culture
• /
• v.33 no.5
• /
• pp.444-450
• /
• 2018

This study was conducted to optimize the level of sugar added (20 (control), 15, 10, 5%) during the preparation of soy sauce-salted mushrooms (Pleurotus eryngii) jangachi without affecting the degree of preference. The salinity and sugar content during storage of soy sauce-salted mushrooms (Pleurotus eryngii) jangachi decreased significantly as the level of sugar added decreased. The moisture content was found to increase as the level of sugar added decreased. Additionally, the pH increased, while hardness decreased as the level of sugar added decreased during 3 weeks of storage. The L value (lightness) was not different from that of the control group until the addition of 10% sugar, while the a value (redness) and b value (yellowness) increased. The antioxidant activity of vitamin C content and DPPH radical scavenging activity increased as sugar content decreased. Upon sensory evaluation of mushrooms (Pleurotus eryngii) jangachi, the highest value in appearance was observed for the 5 and 15% treatments, while 5% had the highest flavor value, 15 and 10% had the highest taste values, 10 and 15% had the highest texture values, the control and 5% had the greatest clarification values, and the 15 and 10% groups had the greatest overall acceptance. These results suggest that a sugar level of 15% can be used without significantly affecting the overall acceptance.

• The Korean Journal of Physiology
• /
• v.29 no.1
• /
• pp.1-11
• /
• 1995

Alveolar macrophages play a pivotal role in the pathogenesis of silicosis since the macrophages may release a wide variety of toxic and inflammatory mediators as well as mitogenic growth factors. In the present study, the effects of in vitro exposure to silica on release of various mediator such as reactive oxygen species, platelet activating factor(PAF), and interleukin-1 (IL-1) by alveolar macrophages were examined. First, hydrogen peroxide release from alveolar macrophages was monitored by measuring the change in fluorescence of scopoletin in the absence or presence of graded concentration of silica. Significantly enhanced release of hydrogen peroxide was observed at 0.5 mg/ml and above. A maximal enhancement of 10 fold above control was observed at 5 mg/ml silica. Similarly, in vitro exposure to silica also significantly stimulated the generation of chemiluminescence from alveolar macrophages at 0.5 mg/ml and above with n maximal enhancement of 8 fold at 5 mg/ml silica. Second, PAF release from alveolar macrophages after 30 min incubation at $37^{\circ}C$ in absence or presence of zymosan and silica was determined by measuring $^{3}H-serotonin$ release ability of the conditioned macrophage supernates from platelets. 5 mg/ml zymosan as a positive control fur the PAF assay increased PAF release by 19 % of total serotonin release. Furthermore, silica also resulted in significant enhancement of the PAF release compared with that in unstimulated (control) cells, i.e., $17.7{\pm}5.8%$ and $24.0{\pm}4.9%$ of total serotonin release at 5 mg/ml and 10 mg/ml silica, respectively, which represents the release of nanomole levels of PAF. Lastly, IL-1 production by alveolar macrophages was analysed following their stimulation with lipopolysaccharide (LPS) and silica by their capacity to stimulate thymocyte proliferation. $10\;{\mu}g/ml$ LPS resulted in an 11 fold increase in IL-1 production. In comparison, $50\;{\mu}g/ml$ silica resulted in a 4 fold increase in IL-1 release. These data indicate that in vitro exposure of alveolar macrophages to silica activates the release of various bioactive mediators such as reactive oxygen species, PAF and IL-1 which thus contribute to amplification of inflammatory reactions and regulation of fibrotic responses by the lung after inhalation of silica.

• Journal of the Mineralogical Society of Korea
• /
• v.11 no.1
• /
• pp.20-31
• /
• 1998

Adsorption of metal elements onto illite and halloysite was investigated at $25^{\circ}C$ using pollutant water collected from the gold-bearing metal mine. Incipient solution of pH 3.19 was reacted with clay minerals as a function of time: 10 minute, 30 minute, 1 hour, 12 hour, 24 hour, 1 day, 2 day, 1 week, and 2 week. Twenty-seven cations and six anions from solutions were analyzed by AAs (atomic absorption spectrometer), ICP(induced-coupled plasma), and IC (ion chromatography). Speciation and saturation index of solutions were calculated by WATEQ4F and MINTEQA2 codes, indicating that most of metal ions exist as free ions and that there is little difference in chemical species and relative abundances between initial solution and reacted solutions. The adsorption results showed that the adsorption extent of elements varies depending on mineral types and reaction time. As for illite, adsorption after 1 hour-reaction occurs in the order of As>Pb>Ge>Li>Co, Pb, Cr, Ba>Cs for trace elements and Fe>K>Na>Mn>Al>Ca>Si for major elements, respectively. As for halloysite, adsorption after 1 hour-reaction occurs in the order of Cu>Pb>Li>Ge>Cr>Zn>As>Ba>Ti>Cd>Co for trace elements and Fe>K>Mn>Ca>Al>Na>Si for major elements, respectively. After 2 week-reaction, the adsorption occurs in the order of Cu>As>Zn>Li>Ge>Co>Ti>Ba>Ni>Pb>Cr>Cd>Se for trace elements and Fe>K>Mn>Al, Mg>Ca>Na, Si for major elements, respectively. No significant adsorption as well as selectivity was found for anions. Although halloysite has a 1:1 layer structure, its capacity of adsorption is greater than that of illite with 2:1 structure, probably due to its peculiar mineralogical characteristics. According to FTIR (Fourier transform infrared spectroscopy) results, there was no shift in the OH-stretching bond for illite, but the ν1 bond at 3695 cm-1 for halloysite was found to be stronger. In the viewpoint of adsorption, illite is characterized by an inner-sphere complex, whereas halloysite by an outer-sphere complex, respectively. Initial ion activity and dissociation constant of metal elements are regarded as the main factors that control the adsorption behaviors in a natural system containing multicomponents at the acidic condition.

• Journal of Microbiology
• /
• v.45 no.4
• /
• pp.318-325
• /
• 2007

Glucose 6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49) in Deinococcus radiophilus, an extraordinarily UV-resistant bacterium, was investigated to gain insight into its resistance as it was shown to be involved in a scavenging system of superoxide $(O_2^{-1})$ and peroxide $(O_2^{-2})$ generated by UV and oxidative stresses. D. radiophilus possesses two G6PDH isoforms: G6PDH-1 and G6PDH-2, both showing dual coenzyme specificity for NAD and NADP. Both enzymes were detected throughout the growth phase; however, the substantial increase in G6PDH-1 observed at stationary phase or as the results of external oxidative stress indicates that this enzyme is inducible under stressful environmental conditions. The G6PDH-1 and G6PDH-2 were purified 122- and 44-fold (using NADP as cofactor), respectively. The purified G6PDH-1 and G6PDH-2 had the specific activity of 2,890 and 1,033 U/mg protein (using NADP as cofactor) and 3,078 and 1,076 U/mg protein (using NAD as cofactor), respectively. The isoforms also evidenced distinct structures; G6PDH-1 was a tetramer of 35 kDa subunits, whereas G6PDH-2 was a dimer of 60kDa subunits. The pIs of G6PDH-1 and G6PDH-2 were 6.4 and 5.7, respectively. Both G6PDH-1 and G6PDH-2 were inhibited by both ATP and oleic acid, but G6PDH-1 was found to be more susceptible to oleic acid than G6PDH-2. The profound inhibition of both enzymes by ${\beta}-naphthoquinone-4-sulfonic$ acid suggests the involvement of lysine at their active sites. $Cu^{2+}$ was a potent inhibitor to G6PDH-2, but a lesser degree to G6PDH-1. Both G6PDH-1 and G6PDH-2 showed an optimum activity at pH 8.0 and $30^{\circ}C$.

• Journal of Environmental Science International
• /
• v.19 no.10
• /
• pp.1307-1314
• /
• 2010

This study was conducted to isolate and characterize a novel feather-degrading bacterium producing keratinase activity. A strain K9 was isolated from soil at poultry farm and identified as Xanthomonas sp. K9 by phenotypic characters and 16S rRNA gene analysis. The cultural conditions for the keratinase production were 0.3% fructose, 0.1% gelatin, 0.04% $K_2HPO_4$, 0.06% $KH_2PO_4$, 0.05% NaCl and 0.01% $FeSO_4$ with an initial pH 8.0 at $30^{\circ}C$ and 200 rpm. In an optimized medium containing 0.1% chicken feather, production yield of keratinase was approximately 8-fold higher than the yield in basal medium. The strain K9 effectively degraded chicken feather meal (67%) and duck feather (54%), whereas human nail and human hair showed relatively low degradation rates (13-22%). Total free amino acid concentration in the cell-free supernatant was about 25.799 mg/l. Feather hydrolysate produced by the strain K9 stimulated growth of red pepper, indicating Xanthomonas sp. K9 could be not only used to increase the nutritional value of chicken feather but also a potential candidate for the development of natural fertilizer applicable to crop plant soil.

• Preventive Nutrition and Food Science
• /
• v.10 no.2
• /
• pp.122-129
• /
• 2005

Chlorine dioxide $(ClO_2)$ treatment was evaluated for microbial growth inhibition and its effects on the quality of vacuum-packaged chicken breasts. Chicken breast samples were treated with 3, 50, and 100 ppm of $ClO_2$ solution, respectively. After $ClO_2$ treatment, chicken breast samples were individually vacuum-packaged and stored at $4^{\circ}C$, a typical storage temperature for meat and meat product, for 7 days. The vacuum-packaged chicken breasts treated with $ClO_2$ had significantly lower total bacteria, yeast and mold, total coliform, and Salmonella spp. were significantly reduced by $ClO_2$ treatment. $D_{10}-values$ of total bacteria count, yeast and mold, total coliform, and Salmonella spp. in vacuum-packaged chicken breasts was 93, 83, 85, and 50 ppm, respectively. The pH of vacuum-packaged chicken breasts decreased with increasing $ClO_2$ concentration. Thiobarbituric acid reacted substance (TBARS) values of vacuum-packaged chicken breasts increased during storage, regardless of $ClO_2$ concentration. $ClO_2$ treatment caused negligible changes in Hunter L, a, and b values in the vacuum-packaged chicken breasts. Sensory evaluation of the vacuum-packaged chicken breasts showed that there were no significant changes among the samples treated with various $ClO_2$ concentration. These results indicate that $ClO_2$ treatment could be useful in improving the microbial safety and quality of meat products.