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노쇠중인 밀 잎에서 scorbate-Glutathione회로 관계 효소의 발달에 대한 Benzyladenine의 효과

  • 장창덕
    • Journal of Plant Biology
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    • v.38 no.1
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    • pp.47-54
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    • 1995
  • The present study performed the isolation of cytosolic ascorbate peroxidase (APX) isozymes and analyzed the pattern of their activity development and also investigated the change in some other enzyme activities related to the ascorbate-glutathione pathway from the senescing wheat leaves. The aim of this work is to examine the possibility that in the cytoplasm of wheat leaves the ascorbate-glutathione pathway p!ays a significant role in relation to leaf senescence involving an $H_2O_2$ accumulation and then to show the effect of benzyladenine (BA) on that pathway. During the leaf senescence characterized by increases in ChI breakdown and H202 accumulation under the 4-day dark incubation of matured leaf segments; i) no significant increase of total cytosolic APX was observed, ii) a dehydroascorbate reductase (DHAR) activity was decreased rapidly, iii) a slight increase of glutathione reductase (GR) activity occurred. In the BA-treated leaves; however, i) the total activity of APX increased conspicuously, ii) the decrease of DHAR activity was relatively inhibited, iii) the GR activity increase was more enhanced, and iv) the decrease of ascorbate content and the increase of H202 content were retarded as compared with those of control leaves. Three isozymes of cytosolic APX were found by using a native-electrophoretic gel in senescing wheat leaves and two of them occurred with major activity. In the developmental patterns of cytosolic APX isozymes, only two isozyme bands ("a" and "b") appeared with almost constant activity through 4 days of incubation in the control leaves, while one additional weak isozyme band ("c") and a little increase of "b" isozyme activity were detected in the BA-treated leaves. EspeciaUy, the development of "a" isozyme activity increased remarkably compared with that of control leaves. The increased capacity for peroxide scavenging due to the enhanced activity of all 3 enzymes (APX, DHAR, GR) participating in the ascorbate-glutathione pathway in BA-treated leaves suggested that this pathway might playa significant role in the processes related to the wheat leaf senescence.scence.

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Effect of Blue Light on the Major Components of Soybean-sprouts (Blue광(光) 조사(照射)가 콩나물의 주요성분(主要成分)에 미치는 영향(影響))

  • Kim, Kwang-Soo;Kim, Soon-Dong;Kim, Jin-Koo;Kim, Ju-Nam;Kim, Kyoung-Ju
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.11 no.4
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    • pp.7-12
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    • 1982
  • Growth of soybean sprouts(Glycine Max L.) and amounts of some chemical components were measured when they were exposed to blue light (120lux, 3hrs/day) during their growth. Hypocotyl length of irradiated soybean sprouts exceeded slightly that of control (dark) soybean sprouts, but the tfresh weight of whole sprouts as well as each part of the sprout showed no difference between the two groups. Chlorophyll content of cotyledon under blue light increased significantly with the lapse of days (3.57 and $8.45\;{\mu}g/100g$ fresh weight on the 3rd and 7th day). Bluelight irradiated sprouts contained more vitamin C than control sprouts (21.7% and 30.8% higher for the cotyledon and hypocotyl). Total amount of protein was not affected. Hypocotyl protein content was 8% of that in original soybean. Blue light did not affect the activity of trypsin inhibitor of sprouts. Similar activity of the inhibitor was observed in the cotyledon whereas hypocotyl showed activity corresponding to 23.7% of original bean. Polyacrylamide gel electrophoretogram for the protein showed 10, 9, and 11 bands in the original bean. 5th day cotyledon and hypocotyl respectively. Especially, band 3 of low Rm value was major protein component for the hypocotyl. Band 5 and 11 could be seen only in the protein of hypocotyl from bluelight irradiated sprouts, whereas no effect of blue light on the electrophoretogram was observed for the cotyledon.

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Production of Medium-chain-length Poly (3-hydroxyalkanoates) by Pseudomonas sp. EML8 from Waste Frying Oil (Pseudomonas sp. EML8 균주를 이용한 폐식용류로부터 medium-chain-length poly(3-hydroxyalkanoates) 생합성)

  • Kim, Tae-Gyeong;Kim, Jong-Sik;Chung, Chung-Wook
    • Journal of Life Science
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    • v.31 no.1
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    • pp.90-99
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    • 2021
  • In this study, to reduce the production cost of poly(3-hydroxyalkanoates) (PHA), optimal cell growth and PHA biosynthesis conditions of the isolated strain Pseudomonas sp. EML8 were established using waste frying oil (WFO) as the cheap carbon source. Gas chromatography (GC) and GC mass spectrometry analysis of the medium-chain-length PHA (mcl-PHAWFO) obtained by Pseudomonas sp. EML8 of WFO indicated that it was composed of 7.28 mol% 3-hydrxoyhexanoate, 39.04 mol% 3-hydroxyoctanoate, 37.11 mol% 3-hydroxydecanoate, and 16.58 mol% 3-hydroxvdodecanoate monomers. When Pseudomonas sp. EML8 were culture in flask, the maximum dry cell weight (DCW) and the mcl-PHAWFO yield (g/l) were showed under WFO (20 g/l), (NH4)2SO4 (0.5 g/l), pH 7, and 25℃ culture conditions. Based on this, the highest DCW, mcl-PHAWFO content, and mcl-PHAWFO yield from 3-l-jar fermentation was obtained after 48 hr. Similar results were obtained using 20 g/l of fresh frying oil (FFO) as a control carbon source. In this case, the DCW, the mcl-PHAFFO content, and the mcl-PHAFFO yields were 2.7 g/l, 62 wt%, and 1.6 g/l, respectively. Gel permeation chromatography analysis confirmed the average molecular weight of the mcl-PHAWFO and mcl-PHAFFO to be between 165-175 kDa. Thermogravimetric analysis showed decomposition temperature values of 260℃ and 274.7℃ for mcl-PHAWFO and mcl-PHAFFO, respectively. In conclusion, Pseudomonas sp. EML8 and WFO could be suggested as a new candidate and substrate for the industrial production of PHA.

Processing of Water Activity Controlled Fish Meat Paste by Dielectric Heating 1. Formulation and Processing Conditions (내부가열을 이용한 보장성어육(고등어) 연제품의 가공 및 제품개발에 관한 연구 1. 원료${\cdot}$첨가물의 배합 및 가공조건)

  • LEE Kang-Ho;LEE Byeong-Ho;You Byeong-Jin;SUH Jae-Soo;JO Jin-Ho;JEONG In-Hak;JEA Yoi-Guan
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.17 no.5
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    • pp.353-360
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    • 1984
  • As an effort to expand the utilization of mackerel which has been thought disadvantageous to processors due to the defects in bloody dark color of meat, high content of lipid, and low stability of protein, and to develope a new type of product, so called, preservative fish meat paste, the processing method was studied in which dielectric heating was applied by means of cooking, pasteurization, dehydration, and control of water activity. The principle of this method is based on that dielectric heating can initiate a rapid dispersion or displacement of moisture in the meat tissue so that the level of water acivity can be controlled by dehydration with hot air meanwhile the product is cooked, pasteurized, and texturized. And the product is finally heated with electric heaters and vacuum sealed to stabilize water activity and storage stability. In present paper, a formula for preparing the fish meat-stach paste, the conditions of dielectric heating and dehydration, shape and size of the product, and other parameters were tested to optimize the process operation. A formula of the fish meat-starch paste to provide proper textural properties and water activity was $10\%$ starch, $1.5\%$ salt, $3\%$ soybean, $0.6\%$ MSG, $2\%$ sucrose, and $3\%$ sorbitol against the weight of fish meat. A proper shape and size of the product to avoid foaming and case hardening during heating was sliced disc of 8 cm $diameter{\times}0.8$ cm thickness or $10{\times}10$ cm square plate with 1.0 cm thickness. The disc shape was recommended because it resulted more uniform heating, minimum foaming and case hardening. And it was also advantageous that disc was simply provided when the fish meat disc was stuffed in the same, solidified in boiling water for 2 to 3 minutes, and sliced. Condition of dielectric heating was critical to decide the levels of sterility, water activity, and textural property of the product. The temperature at the center of the meat disc slices was raised up to $95^{\circ}C$ in 1.5 minutes so that continuous exposure to microwave caused expanded tissue and hardening ending up with a higher water content. Heating for 5 to 6 minutes was adequate to yield the final water activity of 0.86 to 0.83(35 to $40\%$ moisture). It is important, however, that heating had to be done periodically, for instance, in the manner of 2.0, 1.5, 1.5, and 1.0 minute to give enough time to displace or evaporate moisture from the meat tissue. The product was dehydrated for 2 to 3 minutes by hot air of $60^{\circ}C$, 3 to 5m/sec and finally exposed to electric heaters for 5 to 6 minutes until the surface was roasted deep brown. These conditions of heating and dehydration resulted in a complete reduction of total plate count from an initial count of $5.3{\times}10^6/g$ to less than $3{\times}10^2/g$. General composition of the product was $40.1\%$ moisture, $20.8\%$ protein, $17.4\%$ lipid, $16.2\%$ carbohydrate, and $5.5\%$ ash. Textural properties revealed folding test AA, hardness 42, cohesiveness 0.53, toughness 4.6, and elasticity 0.8.

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Biodiesel production using lipase producing bacteria isolated from button mushroom bed (양송이 배지에서 유래한 Lipase 생산균을 이용한 바이오디젤 생산)

  • Kim, Heon-Hee;Kim, Chan-Kyum;Han, Chang-Hoon;Lee, Chan-Jung;Kong, Won-Sik;Yoon, Min-Ho
    • Journal of Mushroom
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    • v.13 no.1
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    • pp.56-62
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    • 2015
  • A lipase producing bacterium was isolated from button mushroom bed, which showing high clear zone on agar media containing Tributyrin as the substrate. The strain was identified as Burkholderia cepacia by analysis of 16S rDNA gene sequence. Crude lipase (CL) was partially purified from 70% ammonium sulfate precipitation using the culture filtrate of B. cepacia. Immobilized lipases were prepared by cross-linking method with CL from B. cepacia and Novozyme lipase (NL) onto silanized Silica-gel as support. Residual activitiy of the immobilized CL (ICL) and immobilized NL (INL) was maintained upto 61% and 72%, respectively. Biodiesel (Fatty acid methyl ester, FAME) was recovered by transesterification and methanolysis of Canola oil using NaOH, CL and ICL as the catalysts to compare the composition of fatty acids and the yield of FAME. Total FAME content was NaOH $781mg\;L^{-1}$, CL $681mg\;L^{-1}$ and ICL $596mg\;L^{-1}$, in which the highest levels of FAME was observed to 50% oleic acid (C18:1) and 22% stearic acid (C18:0). In addition, the unsaturated FAME (C18:1, C18:2) decreased, while saturated FAME (C16:0, C18:0) increased according to increasing the reaction times with both CL and ICL, supporting CL possess both transesterification and interesterification activity. When reusability of ICL and INL was estimated by using the continuous reaction of 4 cycles, the activity of ICL and INL was respectively maintained 66% and 79% until the fourth reaction.

Characteristics of Histamine Forming Bacteria from Tuna Fish Waste in Korea (국내 참치 부산물 내 히스타민 생성 주요 세균의 특성 구명)

  • Bang, Min-Woo;Chung, Chang-Dae;Kim, Seon-Ho;Chang, Moon-Baek;Lee, Sung-Sil;Lee, Sang-Suk
    • Journal of Life Science
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    • v.19 no.2
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    • pp.277-283
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    • 2009
  • Biogenic amines are generally formed through the decarboxylation of specific free amino acids by exogenous decarboxylases released by microbial species associated with the fish products and fermented feeds. This study was conducted to investigate the properties of e tuna waste regarding the control of degradation of biogenic amines (histamine, tyramine, tryptamine, putrescine, and cadaverine) that might be related with the anti-nutritional factor of the tuna waste that is used for manufacturing domestic fish meal. The values of pH and the salt content were 6.51, 3.35% in tuna waste and 5.58 and 5.83% in tuna fish meal, respectively. The strains and dominant bacteria tested in the tuna waste sample were 9.20, 9.29, 5.67, 7.82 and 7.58 log CFU/g of total bacteria, aerobic plate count (APC), total coliform (TC), Lactobacillus spp. and Bacillus spp., respectively. The main histamine forming-bacteria (HFB) in tuna waste were detected by silica gel thin-layer chromatography (TLC) and 7 histamine-forming bacterial species were isolated among microbes grown in selective medium. The histamine concentration was determined by detection of fluorescence of ο-phthaldialdehyde (OPA) derivatives using HPLC and the date were used to reconfirm the identities of the amine-producing bacteria. The 15 histamine- forming bacteria strains grown in trypicase soy broth (TSB) supplemented with 1% L-histidine (TSBH) were identified as Lactococcus(L.) lactis subsp. lactis, Klebsiella pneummonlae, L. garvieae 36, Vibrio olivaceus, Hafnia alvei and L. garvieae which were main dominant amine - producing strains, and Morganella morganii identified by 16S ribosomal RNA (rRNA) sequencing with PCR amplification. A Phylogenetic tree generated from the 16S rRNA sequencing data showed different phyletic lines that could be readily classified as biogenic amine forming gram-positive and negative bacteria.

Studies on the Effects of Amylase Addition to Rice Extrusion on the Rheological Properties of the Extrudate for Weaning Food Base (압출조리를 이용한 쌀 이유식 제조에서 아밀라제 첨가가 물성변화에 미치는 효과)

  • Lee, Gang-Gweon;Kim, Ji-Yong;Lee, Cherl-Ho
    • Korean Journal of Food Science and Technology
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    • v.26 no.6
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    • pp.670-678
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    • 1994
  • The effects of amylase addition during extrusion cooking of rice on the physico-chemical properties of the extrudates were investigated in order to develop rice-based Korean style weaning food products. A laboratory-built single screw extruder was used, the enzymes used were Termamyl 120LS(amylase from Bacillus licheniformis, NOVO Co.), BAN 240L(amylase from Bacillus amylolichuefaciens, NOVO Co.) and malt powder. By the addition of enzymes, the water soluble index of the extrudates increased by 3 times compared to that of the extrudates without enzyme and the concentration of reducing sugar in the extrudates increased drastically at 28 feed moisture. The gel permeation chromatographic pattern showed that the large molecular starch fractions diminished by the addition of enzyme during extrusion and the low molecular fraction increased. The residual enzyme activity in the extrudate were 27% for the most thermo-resistance enzyme by treating at $140^{\circ}C$ in the metering section of the extruder. The sediment volume of the extrudate dispersion increased as the metering section temperature increased to $140^{\circ}C$ . By the addition of enzymes the viscosity of extrudate dispersion was redused $1/4{\sim}1/200$ of that of the extrudates without enzyme. It allowed to use 1.8 times of solid material to the weaning food formulation to attain the same level of consistency as the commercial products. It proves that the addition of amylase during rice extrusion is effective to increase the energy density of weaning food by starch degradation, which results in the increases of water solubility, reducing sugar content, dispersibility and fluidability.

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The Effect of Heating Rate by Ohmic Heating on Rheological Property of Corn Starch Suspension (Ohmic Heating에 의한 가열속도 변화가 옥수수전분의 물성특성에 미치는 영향)

  • Lee, Seok-Hun;Jang, Jae-Kweon;Pyun, Yu-Ryang
    • Korean Journal of Food Science and Technology
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    • v.37 no.3
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    • pp.438-442
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    • 2005
  • Granule swelling is essential phenomenon of starch gelatinization in excess water, and characteristic of heated starch dispersion depends largely on size and distribution of swelled starch granule. Although swelling characteristic of starch granules depends on type of starch, heating rate, and moisture content, influence of heating rate on swelling phenomenon of starch granule has not been fully discussed, because constant heating rate of starch dispersion cannot be obtained by conventional heating method. Ohmic heating, electric-resistant heat generation method, applies alternative current to food materials, through which heating rate can be easily controlled precisely and conveniently at wide range of constant heating rates. Starch dispersion heated at low heating rates below $7.5^{\circ}C/min$ showed Newtonian fluid behavior, whereas showed pseudoplastic behavior at heating rates above $16.4^{\circ}C/min$. Apparent viscosity of starch dispersion increased linearly with increasing heating rate, and yield stress was dramatically increased at heating rates above $16.4^{\circ}C/min$. Average diameter of corn starch granules during ohmic heating was dramatically increased from $30.97\;to\;37.88\;{\mu}m$ by increasing heating rate from $0.6\;to\;16.4^{\circ}C/min$ (raw corn starch: $13.7\;{\mu}m$). Hardness of starch gel prepared with 15% corn starch dispersion after heating to $90^{\circ}C$ at different heating rates decreased gradually with increasing heating rate, then showed nearly constant value from $9.4\;to\;23.2^{\circ}C/min$. Hardness increased with increase of heating rate higher than $23.2^{\circ}C/min$.

Studies on Salient Metabolites of Plant Tissues (I) -Nitrogen Metabolism and Proline Accumulation in Halophytes- (식물조직계(植物組織系)의 유효성분(有效成分)에 관(關)한 연구(硏究) [1] -내염성(耐鹽性) 식물(植物)의 Proline축적(蓄積) 및 질소대사(窒素代謝)-)

  • Cho, I.H.
    • Applied Biological Chemistry
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    • v.20 no.2
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    • pp.221-227
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    • 1977
  • Contents of proline and chloride in halophytes were $80-1700\;{\mu}g/gfw$ and 0.13-0.45 mM/gfw respectively. The content of proline was inversely proportional to that of chloride. Rhizomes of Phargmites communis Trin, a halophyte, were grown in non-saline medium and then taken to saline treatment for one or two weeks. Growth of P. communis was inhibited when salinized with 0.25M NaCl. Total nitrogen decreased and alcohol soluble nitrogen and proline increased when growth was retarded. The quantity of Fraction 1 protein decreased at 0.25M NaCl treatment. The accumulation of proline at high concentration in P. communis suggested that it might play a role in osmotic adjustment.

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Phase Transformation of 2 Components(CaO-, $Y_2O_3$-, MgO-$ZrO_2$) and 3 Components(MgO-$ZrO_2-Al_2O_3)$ Zirconia by X-ray Diffraction and Raman Spectroscopy (X-선회절과 Raman 분광분석을 이용한 2성분계(CaO-, $Y_2O_3$-, MgO-$ZrO_2$) 및 3성분계(MgO-$ZrO_2-Al_2O_3)$ Zirconia의 상전이연구)

  • 은희태;황진명
    • Journal of the Korean Ceramic Society
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    • v.34 no.2
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    • pp.145-156
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    • 1997
  • ZrO2 phase transformations depending on the type and amount of dopants and the sintering temperatures were studied for the 2 components (CaO-, Y2O3-, MgO-ZrO2) and the 3 components(MgO-ZrO2-Al2O3)ZrO2 powder by X-ray diffraction and Raman spectroscopy. In the CaO- and Y2O3-ZrO2 systems, as the CaO and Y2O3 contents increased to 6~15mol% and 3~15mol% respectively, we were not able to identify between tetragonal and cubic in the X-ray diffraction patterns. On the other hand, all Raman modes shifted to lower wavenumbers, decreasing in intensity and the number of bands, markedly. These phenomena were caused by tetragonallongrightarrowcubic phase transformation and interpreted by the breakdown of the wave vector selection rule(k=0) and the structural disorder associated with the formation of oxygen sublattice which was caused by the substitution between Zr4+ ion and Ca2+ or Y3+ ion in ZrO2 matrix. The monoclinic to cubic phase transformation occurred in 10mol% MgO-ZrO2 system. As the Al2O3 content increased from 0 to 20mol% in the MgO-ZrO2-Al2O3 systems, cubic phase transformed to monoclinic phase, this is because the MgO didn't play a role in a stabilizer because of the formation of the spinel(MgAl2O4) by the reaction between MgO and Al2O3, Also, the ZrO2 phase transformation was explained by the change of it's lattice parameters depending on the type and amount of dopants. Namely, as the amount of dopant increased to 10~13mol%, the axial ra-tio c/a came close to unity with increasing the lattice parameter a and decreasing the lattice parameter c. At that time, the tetragonallongrightarrowcubic phase transformation occurred.

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