• Title/Summary/Keyword: Chemistry

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Effects of Rennin and/or Starter Addition on the Manufacture and Ripening of Soybean Cheeses (Rennin 및 Starter의 첨가(添加)가 대두(大豆)치즈의 제조(製造) 및 숙성(熟成)에 미치는 영향(影響))

  • Jeong, Jae Hong;Choi, Woo Young
    • Korean Journal of Agricultural Science
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    • v.7 no.2
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    • pp.190-201
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    • 1980
  • This experiment was designed to optimize the process of manufacturing the soybean cheeses and to elucidate the chemical changes during ripening when the chemical changes during ripening when the milk components and enzyme preparations were added to the raw materials. Conditions for extracting soybean protein such as temperature, duration and amount of water added were determined; various coagulaters were compared by checking the curd texture and yield; starters from S. thermophilus, S. lactis MLB and S. cremoris EB-9 were tested as single- or multi-stain combinations; and the effects of skim milk and/or rennins-both microbial and calf origin-addition upon the process of manufacturing and ripening were studied. The results obtained were as follows. 1. optimal conditions for soybean extraction were found to be: temperature $100^{\circ}C$, duration 10 minutes, and amount of water added 9-fold, as considered the extraction rate of solids and proteins, and curd yield. 2. Sodium gluconate was the most effective among the coagulators tested, and 5% of single-strain starter from S. thermophilus was appered to be adequate inoculum for curd formation. 3. The effects of skim milk and/or rennins addition on the process of manufacturing and ripening of soybean cheeses were: 1) The addition of rennins resulted in fast formation of curd, especially with skim milk it was so. And Hansen rennet extracts brought better results in curd formation than Meito rennet extracts did. 2) No significant effect was observed on the changes in moisture content during ripening, however the levels of moisture contents in the products were higher in case of using Meito rennet extracts. 3) Effect on pH changes during ripening was also not significant in general, while levels of pH were decrease markedly during manufacturing and the initial stage of ripening. 4) The levels of bacterial counts were much higher in case of skim milk addition throughtout the ripening period. In general the numbers were reached to approximately $10^8cells/g$ during manufacturing, then decreased gradually to below $10^2cells/g$ in 8 weeks of ripening. 5) The addition of skim milk and/or rennin resulted in higher ripening index, and skim milk plus Meito rennet extracts was appeared to be best combination for the ripening index.

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Bond Orbital Theory of Chemical Reactivity (反應性의 結合 Orbital 理論)

  • Yang, Kang;Ree, Tai-Kyue
    • Journal of the Korean Chemical Society
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    • v.8 no.1
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    • pp.20-24
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    • 1964
  • The linear combination of bond orbitals method is used to investigate the reactivity of halomethanes in abstraction reactions by atoms. The activation energy is evaluated on the assumption that, in an activated complex, two electrons in a bond to be broken become completely isolated from the rest of the ${\sigma}$-electron systems. Such a model leads to an intuitively attractive concept that the interactions between the reactive bond and the neighboring bonds govern the reactivity of ${\sigma}$-electron systems. The resulting equation for the activation energy, ${\varepsilon},\;is:\;{\narepsilon}= ${\varepsilon}={\zeta}+$$${\sum}_{i=1}^3$${\eta}c-I,$ c-4 Here, subscript C-4 indicates the bond to be broken, while C-i represents the other three bonds surrounding the reactive bond; ξ is the activation energy of a hypothetical reaction of an isolated C-4 bond and an attacking atom; and ${\eta}$C-i,C-4 stems from the stabilizing interacting of C-4 bond with neighboring C-i bonds. A choie of η′s consistent with bond strength data simplifies the above equation to a form ${\varepsilon}={\zeta}\;+\;N{\eta}c$-H, C-4 where N denotes the number of C-H plus C-F bond in halomethanes. In agreement with this equation, experimental -values increase linearly with increasing N.

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Spectrophotometric Determination of Aluminium Ion in Drinking Water by Flow Injection Analysis (흐름주입분석법에 의한 음용수 중 알루미늄 이온의 분광광도법 정량)

  • Choi, Yong-Wook;Jin, Jae-Young
    • Journal of the Korean Chemical Society
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    • v.44 no.5
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    • pp.422-428
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    • 2000
  • Optimum analytical conditions of the aluminium ion were established by flow injection analysis. Eriochrome Cyanine R(ECR) dye reacts with the aluminium ion at pH 6.0 to form a complex that exhibits maximum absorption at 535 nm. Reaction conditions including the mixing and the reaction coil length, the concentration and the pH of the buffer solutio, temperature, and injection loop volume were optimized to intro-duce this reaction into flow injection analysis. The results were as follows. A mixing coil length of 0.5 m and a reaction coil length of 4.0 m, the pH 6.0 and 1M of acetate buffer solution, the ECR concentration of 0.56 mM, the reaction temperature of 40$^{\circ}C$, the injection loop volume of 300${\mu}L$ were chosen as optimum conditions. Under these conditions the detection limit of the aluminiumion was less than 0.05 mg/L and the repeatability was better than 1%. A sampling frequency of 24 times for an hour was achieved. Interfering ions such as $F^-$, HP$O_4^{2-}$, $Fe^{2+}$, $Fe^{3+}$, $Mn^{2+}$, and other anions were tested, interference did not occur up to 1,000mg/L of ion concentration and up to 2,CO0mg/L of sulfate ion con-centration. This method was applied for the determination of aluminium ion in tap water and ground water of Jeonju and the Gochang area. The results showed that the aluminium residual in tap water of the Jeonju area was at a mean of 0.478mg/L and that in tap water of the Gochang area was at a mean of 0.278mg/L. Aluminium ion residual of the tap waters in the Jeonju area was higher level than that in the Gochang area. Aluminium residual in the ground water of the Jeonju area was 0.386 mg/L and was lower compared to 0.564 mg/L for the Gochang area.

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Phylogenetic Relationships Among Pleurotus species Inferred from Sequence Data of PCR Amplified ITS II Region in Ribosomal DNA (rDNA의 ITS II 부위의 염기서열분석에 의한 느타리버섯 종간의 근연관계)

  • Bae, Shin-Churl;Seong, Ki-Young;Lee, Shin-Woo;Go, Seung-Joo;Eun, Moo-Young;Rhee, In-Koo
    • The Korean Journal of Mycology
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    • v.24 no.2 s.77
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    • pp.155-165
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    • 1996
  • This study was carried out to identify the phylogenetic relationship among several isolates of Pleurotus species by comparing ITS II region of ribosomal DNA(rDNA) repeat unit. Two primers from ribosomal DNA sequences were chosen to amplify the specific internal transcribed spacer (ITS) II region of Pleurotus spp. The exact ITS II region with an unique band from six species of Pleurotus genus could be amplified using the two primers taken from at the 3'-end of 5.8S rDNA and 5'-end of 28S rDNA. Six representative species of the Pleurotus genus were easily characterized according to the length differences of ITS II region. Furthermore, within P. ostreatus species, different sizes of ITS II region could be observed in the isolates of ASI 2025 and ASI 2095 although they were classified as P. ostreatus by the conventional observation. The nucleotide sequence analyses of PCR-amplified ITS II region indicated that the isolates ASI 2025 and ASI 2095 were different from other Pleurotus spp. When the nucleotide sequences of six Pleurotus species were compared, three typical ITS II regions were highly variable especially at both ends of this region. The phylogenetic tree obtained by the Neighbor program of Felsenstein PHYLIP package with all the nucleotide sequence of Pleurotus spp. indicated that P. ostreatus, P. florida, P. sajor-caju and P. eryngii were closely related to one phylogenetic branch and P. cystidious was related to other branch with P. cornucopiae. The isolates ASI 2025 and 2038, however, were not closely related to any other Pleurotus spp. and formed their own individual branches.

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Toxicity of lectin extracted from Korean mistletoe (Viscum album coloratum) in piglets and its effects on the immunogenicity of Aujeszky's disease virus vaccines (한국산 겨우살이(Viscum album coloratum)로부터 추출된 lectin의 돼지에 대한 독성 및 오제스키병 백신의 면역원성에 미치는 영향)

  • Yeo, Sang-Geon
    • Korean Journal of Veterinary Research
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    • v.46 no.3
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    • pp.225-234
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    • 2006
  • In the present study toxicity and immunostimulating activity of the lectin(KML-C), which was extracted from Korean mistletoe(Viscum album coloratum) were investigated in swine. To determine the toxicity, lectin was injected into thigh or cervical muscles of 4-week-old piglets(Landrace) and observed clinically and pathologically. For determination of the immnunostimulating activity, lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine of Aujeszky's disease virus(ADV)(NYJ1-87) which was inactivated by 0.2% formalin was injected into the cervical muscle of antibody-negative piglets in the same age group. Subpopulation of the immune cells and serum neutralizing(SN) antibodies in the piglets were examined after vaccination, and resistance of the piglets against challenge by virulent NYJ1-87 was further examined. The results were also compared with those from piglets injected with aluminum hydroxide [$Al(OH)_3$]-adjuvanted vaccine of inactivated NYJ1-87 and NYJ1-87 vaccine without adjuvant, and the results are as follows. By injection of lectin with $30{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets died after signs such as dyspnea, fever, systemic erythema and subcutaneous hemorrhages, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with $7{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets showed signs such as edema and cutaneous hemorrhage in the injected area, lameness and depression, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with 1, 3 and $5{\mu}g/kg$ of body weight to the thigh muscle of each one piglet, signs such as congestion, induration and grayish coloration in the injected area, depression and inappetence were observed in all piglets. Toxic changes were also observed in the liver and kidney of piglets by lectin of 3 and $5{\mu}g$. By injection of lectin with 0.5 and $0.7{\mu}g/kg$ of body weight to the cervical muscle of each 9 piglets, all piglets were clinically normal and there were no significant changes in blood counts and chemistry values. Whereas, epithelial swelling and vacuolation of convoluted tubules were observed from one piglet injected with lectin of $0.7{\mu}g$, and necrosis and fibrosis of muscular fiber were observed in the muscle of one piglet injected with lectin of $0.5{\mu}g$. Only population of sIgM+ B lymphocytes increased among immune cells in all of 15 piglets immunized with lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine, while compared to those in $Al(OH)_3$-adjuvanted vaccine and vaccine without adjuvant. No additional stimulation to the immune cells was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. In piglets immunized with lectin-adjuvanted vaccine, SN titers in reciprocal values for loge were 1.3-4.0 at 1-4 weeks after vaccination, which was similar to those with 1.0-3.3 by vaccine without adjuvant but lower than those with 2.0-5.7 by $Al(OH)_3$-adjuvanted vaccine. Also, no additional increase in the SN titers was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. Piglets immunized with lectin-adjuvanted vaccine were resistant to challenge by the virulent NYJ1-87 at 4 weeks after vaccination, and the SN titers reached to 5.0 one week after challenge, which was higher than those with 4.0 by vaccine without adjuvant but somewhat lower than those with 7.7 by $Al(OH)_3$-adjuvanted vaccine.

The Toxicological Pathologic Study of Amanita muscaria in Sprague-Dawley Rat (Amanita muscaria 경구투여 시 Sprague-Dawley Rat에서의 독성병리 연구)

  • Kim, Jin;Kim, Hyeong-Jin;Kim, So-Jung;Kim, Byeong-Soo;Kim, Sang-Ki;Park, Byung-Kwon;Park, Young-Seok;Cho, Sung-Dae;Jung, Ji-Won;Nam, Jeong-Seok;Choi, Chang-Sun;Lee, Seung-Ho;Jung, Ji-Youn
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1152-1158
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    • 2009
  • For the toxicological pathologic study of amanita muscaria, we have investigated single and repeated dose toxicity in Sprague-Dawley (SD) rats. Single dose toxicity study was identified as catalepsy, incline and tail pinch methods (control 0 mg/kg, low 3.3 mg/kg, middle 16.5 mg/kg, high 33.0 mg/kg). Repeated dose toxicity study was carried out in blood tests, serum tests and histopathological methods. Neurotoxicity - muscle paralysis, and convulsion and loss of movement - was observed at 33.0 mg/kg group in the single dose toxicity study. Dysfunction of liver and kidney were shown in the repeated oral administration of the amanita muscaria at 3${\sim}$4 weeks. Serum chemistry results revealed a marked increase of LDH [Lactate Dehydrogenase (3181.5 IU/L; normal 230-460 IU/l)], ALT [Alanine transaminase (124.0 IU/l; normal <40 IU/l)] but the kidney was normal. Histopathological results show interstitial edema and tubular epithelial necrosis in the kidney. These results suggest that amanita muscaria has a neurotoxic effect and causes dysfunction of liver and kidney in the SD rat.

Effects of Sasa coreana Nakai on the Lipid Compositions of Serum in High Cholesterol Diet Rats (신의대(Sasa coreana Nakai) 추출물이 고콜레스테롤 식이 투여 흰쥐의 혈청 지질에 미치는 영향)

  • Park, Jong-Ok;Jang, Hye-Won
    • Journal of Life Science
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    • v.19 no.8
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    • pp.1145-1151
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    • 2009
  • This study was performed to investigate the effects of Sineui-Dae (Sasa coreana Nakai, a kind of bamboo) extracts on the improvement of serum lipid composition by using rats fed a hypercholesterol diet for 4 weeks. The experiment animals were administered with the following diets; high cholesterol diet group (HC diet) as a control and three supplemented groups with high cholesterol diets (HCW, HCM or HCH diet). Three kinds of extracts were prepared by orderly extraction with hexane, methanol, and water. We measured free cholesterol, cholesteryl ester, total cholesterol LDL- and HDL-cholesterol triglyceride and phospholipid in the serum of rats in three experimental and control groups. There were no significant differences in body weights and feed intakes between the HC control group and the extract supplemented groups. The levels of total cholesterol and LDL-cholesterol in the serum of extract supplemented groups were lower than that of the group fed with HC diet only. Serum HDL-cholesterol levet which is known as an antiatherosclerosis factor, was higher in all groups supplemented with bamboo extract by 17.2-21.9% compared to the HC control group. All groups supplemented with bamboo extracts showed the lowering effect of atherogenic index compared to the HC control group (HC group: 2.96${\pm}$0.08, HCM group: 1.48${\pm}$0.02, HCW group: 1.69${\pm}$0.04, HCH group: 1.84${\pm}$0.01). Furthermore, serum triglyceride and phospholipid decreased significantly in the HCM diet compared to the HC control diet. These results suggest that Sineui-Dae bamboo extract, especially methanol extract, has improving effects on hyperlipidemia of rats fed a high cholesterol diet.

Single Dose Oral Toxicity Test of Ethanol Extracts of Schisandrae fructus and Mori folium, and their Mixture in ICR Mice (ICR 마우스를 이용한 오미자, 상엽 에탄올 단독추출물 및 복합추출물의 단회경구투여 독성시험)

  • Choi, Eun Ok;Kwon, Da Hye;Kim, Min Young;Hwang-Bo, Hyun;Kim, Hong Jae;Ahn, Kyu Im;Jeong, Jin-Woo;Lee, Ki Won;Kim, Ki Young;Kim, Sung Goo;Choi, Young Whan;Hong, Su Hyun;Park, Cheol;Choi, Yung Hyun
    • Journal of Life Science
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    • v.26 no.10
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    • pp.1207-1213
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    • 2016
  • Schisandrae fructus (SF) and Mori folium (MF) have been used as traditional medicines for thousands of years in parts of Asia, including Korea, China, and Japan. Recent researches on SF and MF have documented a wide spectrum of therapeutic properties, including anti-microbial, anti-inflammatory, anti-oxidative, immunomodulatory and anti-angiogenesis effects. However, the toxicity and safety of SF and MF, and their mixture (medicinal herber mixture, MHMIX) were not confirmed. Therefore, this study was performed to evaluate the acute toxicity and safety of SF, MF and MHMIX. SF, MF and MHMIX were orally administered at a dose of 5,000 mg/kg in ICR mice. Animals were monitored for the mortality and changes in the body weight, clinical signs and gross observation during the 14 days after dosing, upon necropsy. We also measured parameters of organ weight, clinical chemistry, and hematology. No dead and no clinical signs were found during the experiment period after administration of a single oral dose of SF, MF and MHMIX. There were no adverse effects on clinical signs, body weight, or organ weight and no gross pathological findings in any treatment group. Therefore, LD50 value of SF, MF and MHMIX may be over 5,000 mg/kg and it may have no side toxic effect to ICR mice. The results on the single-dose toxicity of SF, MF and MHMIX indicate that it is not possible to reach oral dose levels related to death or dose levels with any harmful side effects.

The Volatile Flavor Components of Fresh Codonopsis lanceolata cultivated on a wild hill (야산 재배 더덕의 휘발성 향기성분에 관한 연구)

  • Kim, Jun-Ho;Choi, Moo-Young;Oh, Hae-Sook
    • Korean journal of food and cookery science
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    • v.22 no.6 s.96
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    • pp.774-782
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    • 2006
  • Flavor components in fresh Codonopsis lanceolata cultivated on a wild hill were detected by headspace sampling(HSS) method and GC-MS equipped with a VB-5(5% phenylmethyl polysiloxane) column. The 167 volatile compounds that were detected, consisted of 28 terpenes and terpene alcohols, 34 hydrocarbon, 31 alcohols, 13 aldehydes and ketones, 25 esters, 6 acids, 10 ethers and 20 miscellaneous components. The ten major volatile flavor components, comprising about 58% of the total, were dl-limonene (10.2%), ${\alpha}$-guaiene (9.0%), 2,2,6-trimethyl-octane (8.6%), hexadecane (8.0%), isolongifolan-8-ol (4.2%), 2,4,4-trimethyl-1,3-pentanediol diisobutyrate (4.1%), ${\beta}$-selinene (3.9%), 2,2,3-trimethylnonane (3.6%), 3-methyl-5-propyl-nonane (3.1%), and ledene (3.1%). The unique aroma of fresh Codonopsis lanceolata described by sensory evaluation was green, earthy, camphoraceous and aldehydic. The components attributed to green or camphoraceous flavor such as 1-hexanol, 2-methylhexan-3-ol, 3-hexen-1-ol, cis-3-hexenyl butyrate, ethylhexanol, hexyl acetate, trans-2-hexen-1-ol, camphor, longiborneol and menthol were not included in the ten or twenty major volatile components which had the largest peak area in descending order. We concluded that the intensity of green and camphoraceous flavor might be used as an indicator of the freshness of Codonopsis lanceolata.

Behavior of the soil residues of the fungicide hexaconazole in a rice plants-grown microecosystem (pot) (살균제 hexaconazole 토양잔류물의 벼 재배 microecosystem(pot)중 행적)

  • Kyung, Kee-Sung;Lee, Byung-Moo;Lee, Jae-Koo
    • The Korean Journal of Pesticide Science
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    • v.8 no.3
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    • pp.198-209
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    • 2004
  • In order to elucidate the behavior of the fungicide hexaconazole in soil and rice plants, rice plants were grown for 42 days in a microecosystem (pot) containing fresh and 28 day-aged soil residues of $[^{14}C]$hexaconazole. The amount of $^{14}CO_2$ evolved during 28 days of aging was 0.11 % of total $^{14}C$-radioactivity treated and the averaged weekly degradation rate was 0.03%. Mineralization rates for 42 days of rice cultivation on fresh and aged paddy soils were 0.67% of the total $^{14}C$ in case of non-rice planting on aged soil and 1.17% in case of rice planting on aged soil, whereas 1.25% in non-rice planting on fresh soil and 1.72% in case of rice planting on fresh soil, suggesting that the amounts of $^{14}CO_2$ were evolved higher from fresh soils than aged ones and from rice-planting soils than non-planting ones. The amounts of volatiles collected were very low as background levels. Most of $^{14}C$-Radioactivity was remained in soil after 42 days of rice cultivation and $^{14}C$ absorbed through rice roots was distributed more in shoots than roots and translocated into the edge of shoots of rice plants. Amounts of non-extractable $^{14}C$ in soils were higher in rice planted soil than in non-planting soil. The distribution of non-extractable $^{14}C$ was increased in the order of humin>fulvic acid>humic acid. The amounts of $^{14}C$ translocated into rotational crop Chinese cabbage were 2.36 and 3.69% of the total $^{14}C$ in case of rice planted soil containing fresh and aged residues, respectively, suggesting that small amounts of $[^{14}C]$hexaconazole and its metabolite(s) were absorbed and their bound residues were more available than their fresh ones to Chinese cabbage.