• Journal of Environmental Science International
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• v.4 no.4
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• pp.367-377
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• 1995

The study of flocculation kinetics is of fundamental interest in the field of water treatment, because rational study of the factors affecting the coagulation process should be based on the rate of particle growth. The effect of sulfate on flocculation kinetics were examined using ferric nitrate as a coagulant to coagulate kaolin clay in water under several experimental conditions. Both the particle size distribution data obtained from the AIA and the on-line measurement of turbidity fluctuation by the PDA were used to measure flocculation kinetics. Results show that sulfate ion added to the kaolin suspension played an important role in the flocculation process, not only improving flocculation kinetics at more acidic pH levels but also changing surface charge of particles. The kinetics of flocculation were improved mainly by the enhanced rate and extent of Fe(III) precipitation attributed to the addition of sulfate, and thereby, better interparticle collision frequency, but little by the charge reductions resulting from the sulfate addition. The increase in sulfate concentration beyond $3\times10^{-4}M (up to 2\times10^{-3}M)$ did not induce further improvement in flocculation kinetics, although the higher concentrations of sulfate ion substantially increased the negative ZP value of particles. Key Words : Flocculation Kinetics, Fe(III) Coagulant, Sulfate ion, Turbidity Fluctuation.

• Nutrition Research and Practice
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• v.4 no.1
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• pp.16-22
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• 2010

Flavonoids are known to be effective scavengers of free radicals. In particular, proanthocyanidins are flavonoids that possess cardiovascular protection, antioxidative activities, and immunomodulatory activities. Here, we evaluated proanthocyanidin contents in the total polyphenolic compounds of pine needle extracts prepared by hot water, ethanol, hexane, hot water-hexane (HWH), and hot water-ethanol (HWE). Analysis of each extract indicated that the ethanol extract contained the highest proanthocyanidin concentration. The HWH and hexane extracts also contained relatively high concentrations of proanthocyanidin. On the other hand, proanthocyanidin content analyses out of the total polyphenolic compounds indicated that the HWH extract contained the highest content. These results suggest that HWH extraction is a suitable method to obtain an extract with a high level of pure proanthocyanidins and a relatively high yield. The HWH extract possessed superior activity in diverse antioxidative analyses such as 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferrous ion chelating (FIC), and ferric-ion reducing power (FRAP) assays. In addition, upon assessing the effects of the pine needle extracts on macrophages (Raw 264.7 cell), the HWH extract exhibited the highest activity. In this study, we discerned an efficient extraction method to achieve relatively pure proanthocyanidins from pine needles and evaluated the biological functions of the resulting extract, which could potentially be used for its efficacious components in functional food products.

• Food Science and Biotechnology
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• v.17 no.1
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• pp.46-51
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• 2008

The objective of this study was to investigate antioxidant activities of freeze-dried, main root, and fine root of ginseng (Panax ginseng CA. Meyer), which were extracted with various solvents including ethanol, methanol, and water. Ethanol extracts in both parts showed the most powerful scavenging activities against DPPH radicals. Especially, ethanol extract of fine root had higher reducing power and antioxidant capacity than that of main root. The highest antioxidant activity in linoleic acid emulsion system was also observed in fine root extracted with ethanol, followed by methanol and water. Both ferrous ion chelating activity and ferric reducing antioxidant power (FRAP) of extracts were increased with the increase of extracts concentration. These results suggest that ethanol extract of fine root of ginseng has the most effective antioxidant capacity compared to the methanol and water extracts tested in the present study. Thus it can be applied for the effective extraction of functional material from ginseng for the usage of pharmaceutical and/or food industries.

• Biomedical Science Letters
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• v.16 no.1
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• pp.33-38
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• 2010

Culinary herbs and spices have received much attention since they contain high concentrations of bioactive ingredients for antioxidant and anti-inflammatory activities. Protection effect of the herb and spice against acute alcohol consumption has been investigated using zebrafish as a vertebrate model. During 30 days bathed in water containing 1% Et-OH and the designated herb or spice, the survival rate of the Et-OH group was decreased sharply (up to 20% at 10 days). The cinnamon-fed group showed the highest and longer survival rate up to 80% up to for 30 days under the presence of Et-OH, while clove-fed group showed 40% survival rate for 25 days. Et-OH group serum exhibited the weakest antioxidant ability from ferric ion removal ability (FRA) assay; FRA ability was increased in the cinnamon-fed group up to 414%, while the clove and laurel group increased 256% and 309%, respectively. Histologic observation and Oil-red O staining showed hepatic tissue damage was severe in the Et-OH group. The cinnamon- or clove-fed group showed much ameliorated hepatic tissue morphology with minimized steatosis. The cinnamon- or clove-fed group showed lower serum GOT and GPT levels than the Et-OH group. Among hepatic tissue extract, the clove-fed group exhibited the lowest level of GOT and GPT. These results suggest that consumption of cinnamon and clove might be beneficial to attenuate progress of acute fatty liver change by alcohol consumption.

• Korean Journal of Microbiology
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• v.20 no.3
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• pp.119-124
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• 1982

As a basic study to elucidate nutritional physiology and composition of synthetic medium of red rotting bacteria, Erwinia carotovora, of ginseng, the effects of hydrogen ion concentration, various kinds of carbon sources, nitrogen source, micrometallic salts and it's concentration on the gorwth of the bacteria were investigated and the results were as follows. Optimal pH in the basal medium for the growth of the bacteria was 6.5. After incubation the pH in culture media was neutralized. Among the various kinds of carbon sources, sucrose, glucose mannitol, but organic acids were not utilized effectively as nutrients. After incubation the pH turned acidic. Alanine as organic nitrogen sources nad ammonium sulfate as inorganic nitrogen promoted the growth, but L-valine and sodium nitrite were the least effective. Ferric chloride 1.0mg/dl and ferrous sulfate 100mg/dl were the most effective as micrometallic sources. Control and boric acid were the least effective. New synthetic medium based on the above results was follows ; Alanine 1.0g, $KH_2PO_4\;1.0g, \;sucrose\;30.0g, \;MgSo_4{\cdot}7H_2O\;0.5g, \;FeCl_3{\cdot}6H_2O\;1.0mg\;thiamine\;200{\gamma}g$, and distilled water 1000ml, pH6.5.

• Microbiology and Biotechnology Letters
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• v.6 no.4
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• pp.167-171
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• 1978

When Asp. niger was shaked at 3$0^{\circ}C$ in 500 mι Erlenmeyer flask with 50 ml of the medium containing 14% of Korean local commercial glucose brand, 0.45% of peptone, and mineral, the citric acid was produced at the level of 37~43 gram per liter in 8 days, and the citric acid production at medium containing X glucose brand was better than that containing Y glucose brand. When the contaminated minerals were removed from the local glucose by Ambelite-IR 120 and peptone by potassium ferrocyanide followed by readjustment of ferric ion content in the medium to 10 mg per liter, the citric acid formation reached 53 gram per liter, a production level of three times higher than that with the original Sakaguchi's medium. The further physiological studies and the mutation of isolated Asp. niger will be needed.

• Microbiology and Biotechnology Letters
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• v.20 no.1
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• pp.40-45
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• 1992

Acidic nucleotidase from Asfiergilius nlger has been partially purified by Sepharose CL-6B gel filtration and DEAE-Sephacel ion exchange chromatography. The optimum pH and temperature for the enzyme reaction with 5'-AMP or 3'-AMP as a substrate were 4.5 and 55%, respectively. However, the optimum temperature became 70% when p-nitrophenyl phosphate was used as a substrate. The enzyme was stable at acidic pH. The enzyme activity was not affected by addition of various nucleotides, nucleosides and inorganic phosphates. Ferric, aluminium, vanadate and molybdate ions inhibited the enzyme activity dramatically. In kinetic studies, $K_m$), values for 3'-AMP, 5'-AMP and p-nitrophenyl phosphate were 1.39 mM, 1.5 mM and 5.77 mM, respectively. The substrate efficiency ($V_{max}/K_m$) shows 3'-AMP is the prefered substrate for the enzyme among tested substrates.

• Korean Journal of Microbiology
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• v.15 no.3
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• pp.123-130
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• 1977

In previous paper, it was reported that antibiotic substance such as tetracycline and streptomycin were produced by S'. albus subsp. and S'. globosus. And increase of mycelial growth of two strains, antibiotic production, and changes of pH range are extended to approximately 110-130 hrs in fermenting medium, there-after they decreased with culture period exception of pH range. Two Streptomyces spp. required commonly 4-5% starch as carbon sources and 1.5-2.0% soybean meal as nitrogen sources. However, 0.005-0.01M potassium phosphate dibasic, calcium carbonate (6mg/ml in S.albus subsp. and 2mg/ml in S. globosus), 0.01-0.03M, magnesium sulgate and 0.01M ferric chloride showed as optimal concentration for the growth of 2 strains. Mineral compoments such as zinc, manganese, cobalt, sodium and copper at the level of 10/sup -4/ -10/sup -6/M were observed. Especially, zinc ion showed toxicity to the growth of 2 strains at 0.005M. In relation with pH, there is a little difference in mycelial growth with cultural initial pH.

• Journal of the Korean Ceramic Society
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• v.29 no.3
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• pp.195-201
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• 1992

It had been studied the structure and the magnetic properties of singel phase Co2Y(Ba2Co2Fe12O22) powder, one of the hexagonal ferrite. The material was successfully prepared by a commercially applicable coprecipitation method. Adding asqueous solution of BaCl2, CoCl2 and FeCl2(Ba2+:Co2+:Fe2+=1:1:6 in mole ratio) to a mixture of NaOH and hydrogen peroxide solution, coprecipitate was formed with rapid oxidation of ferrous to ferric ion. The coprecipitate transformed to single phase Co2Y powder at heat treatment temperatures as low as 900$^{\circ}C$. The shape of Co2Y particles obtained at 900$^{\circ}C$ was hexagonal plate-like (diameter∼$\mu\textrm{m}$, aspect ratio>10). The structure of the Co2Y was refined by a Rietveld analysis of the measured X-ray diffractogram. The lattice parameters are ao=5.8602${\AA}$ and co=43.512${\AA}$. Co2Y is a soft magnetic material with saturation magnetization 30 emu/g and coecivity 170 . A standard X-ray diffraction pattern for Co2Y is proposed as well.

• Korean journal of food and cookery science
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• v.31 no.3
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• pp.335-343
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• 2015

The aim of this investigation was to examine the antioxidation, physicochemical, and sensory activity of a Korean steamed-rice cake, Sulgidduk, fortified with water extracts from Moringa oleifera (M. oleifera) leaf. M. oleifera leaf extracts were added to rice powder at rations of 0.1%, 1% and 10%. To examine antioxidation properties, the scavenging activities of DPPH radicals, hydroxyl radicals, ABTS+ radicals, and ferric ion reducing antioxidant power were investigated. M. oleifera extracts significantly increased the antioxidation activities of Sulgidduk in a dose dependent manner (p<0.05). Physicochemical characteristics were measured by proximate composition, color, texture profile analysis, and sensory evaluations. As the concentration of M. oleifera leaf extracts increased, L-values and a-values significantly decreased while b-values increased. Texture profile analysis demonstrated that the control groups showed significantly higher values for hardness, cohesiveness, chewiness, and adhesiveness as compared with groups containing M. oleifera leaf extract (p<0.05). In the sensory evaluation, the sample containing 0.1% of M. oleifera leaf extract obtained the best results in overall preference. Taken together, these results suggest that M. oleifera leaf may have the potential to increase the consumer acceptability and the functionality of Sulgidduk.