• Title/Summary/Keyword: pH-shifting

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Effects of pH-Shift Processing and Microbial Transglutaminase on the Gel and Emulsion Characteristics of Porcine Myofibrillar System

  • Hong, Geun-Pyo;Chun, Ji-Yeon;Jo, Yeon-Ji;Choi, Mi-Jung
    • Food Science of Animal Resources
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    • v.34 no.2
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    • pp.207-213
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    • 2014
  • This study investigated the effects of microbial transglutaminase (MTGase) and pH-shift processing on the functional properties of porcine myofibrillar proteins (MP). The pH-shift processing was carried out by decreasing the pH of MP suspension to 3.0, followed by re-adjustment to pH 6.2. The native (CM) and pH-shifted MP (PM) was reacted with and without MTGase, and the gelling and emulsion characteristics were compared. To compare the pH-shifted MTGase-treated MP (PT), deamidation (DM) was conducted by reacting MTGase with MP at pH 3.0. Rigid thermal gel was produced by MTGase-treated native MP (CT) and PT. PM and DM showed the lowest storage modulus (G') at the end of thermal scanning. Both MTGase and pH-shifting produced harder MP gel, and the highest gel strength was obtained in PT. All treatments yielded lower than CM, and CT showed significantly higher yield than PM and DM treatments. For emulsion characteristics, pH-shifting improved the emulsifying ability of MP-stabilized emulsion, while the treatments had lower emulsion stability. PM-stabilized emulsion exhibited the lowest creaming stability among all treatments. The emulsion stability could be improved by the usage of MTGase. The results indicated that pH-shifting combined with MTGase had a potential application to modify or improve functional properties of MP in manufacturing of meat products.

Lysinoalanine in Protein Recovered from Frozen Belanger's Croaker, Johnius grypotus, Using Alkaline Processing (알칼리 처리하여 회수한 냉동깡치 어육 단백질의 Lysinoalanine 함량)

  • Kim, Gun-Bae;Lee, Keun-Woo;Hur, Sung-Ik;Choi, Yeung-Joon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.40 no.6
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    • pp.337-342
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    • 2007
  • The formation of lysinoalanine (LAL) in protein recovered from the belanger's croaker, Johnius grypotus, using a pH shifting process was measured by amino acid analysis. The LAL peak was detected at 49.24 min, between phenylalanine and histidine peaks in the amino acid analyzer. LAL was not detected in the fish muscle or in protein recovered using the alkaline pH shifting process. LAL was not formed in protein recovered after storage for up to 9 hrs at pH 11, but was detected in the soluble protein fraction at pH 11, followed heating at $90\;^{\circ}C$. The myosin heavy chain decreased with storage time at pH 11. The results suggest that the alkaline shifting process for recovering fish muscle protein is safe, and that no LAL forms.

Shifting Cultivation Effects on Soil Environment in Upland Watershed of Bangladesh

  • Haque, S.M. Sirajul;Gupta, Sanatan Das;Miah, Sohag
    • Journal of Forest and Environmental Science
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    • v.30 no.2
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    • pp.179-188
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    • 2014
  • This research reports the effects of shifting cultivation on soil environment collecting samples from 0-5 cm soil depth from five locations viz. at Burburichhara, Maichchari, Longadu, Sukurchhari and Muralipara in Rangamati district of Chittagong Hill Tracts (CHTs). Soil analyses showed that fungal and bacterial population, microbial respiration and active microbial biomass, maximum water holding capacity, conductivity and moisture contents were significantly (at least $p{\leq}0.05$) lower in shifting cultivated soil compared to adjacent mixed tree plantations at all the sites. On an average in soils of 5 different shifting cultivated lands fungal population was $1.33{\times}10^5$ CFU/g dry soil and bacterial population $1.80{\times}10^7$ CFU/g dry soil and in mixed plantations fungal population was $1.70{\times}10^5$ and bacterial population $2.51{\times}10^7$ CFU/g dry soil. Organic matter and exchangeable Ca and Mg contents were significantly (at least $p{\leq}0.05$) lower and bulk density significantly (at least $p{\leq}0.05$) higher in shifting cultivated land in most of the locations compared to adjacent mixed tree plantations. Ratios of microbial respiration and organic carbon as well as active microbial biomass and organic carbon were distinctly lower and pH higher at 3 locations in shifting cultivated soils compared to mixed plantations. Findings of various soil properties, therefore, suggest that shifting cultivation has deteriorating effects on soil environment.

Recovery and Utilization of Proteins and Lipids from Washing Wastewater in Marine Manufacture by Isoelectric Point Precipitation Method 1. The Coagulation Treatment for Washing Wastewatfr of Minced Mackerel Meat (수산가공공장 폐액의 등전점 침전처리에 의한 유용성분 재회수 이용 1. 고등어 육 고기풀 제조시 발생되는 폐액의 처리장치 개발)

  • 서재수;조순영
    • KSBB Journal
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    • v.10 no.1
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    • pp.1-8
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    • 1995
  • A lot of water soluble proteins and lipids are released from minced mackerel meat and lost into the washing waste during the leaching process of Kamaboko or surimi manufacture. The removed proteins and lipids are not only an edible things but also a big burden for treating the wastewater. In order to recover the proteins from the effluent and to use as food stuff, the "pH-shifting" treatment, a modified isoelectric point precipitation method, was tried. This method is based on a myogen-aggregation phenomenon, which occurs when a solution of sarcoplasmic proteins is acidified or alkalified beyond the critical pH zone of 2∼3 or 12∼13 respectively and then neutralized. The maximum amount of precipitation was obtained by shifting the pH of the wastewater from original pH to isoelectric point (pH 4) or alkali pH 12 and then changing to neutral pH. The precipitates were easily collected by filteration or centrifuging at 10,000rpm. The oils which were only floating in the washing wastewater are easily recovered by seperating with oil separator after pouring. The recovered proteins were slightly denaturated during this pH shifting precipitation process, while the composition of amino acids was good balance as a food.

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Prognostic Factors of Ruptured Middle Cerebral Artery Aneurysm with Intracerebral Hematoma (뇌실질내출혈을 동반한 중대뇌동맥류 파열 환자의 예후 인자)

  • Lee, Won Chang;Choi, Chang Hwa
    • Journal of Korean Neurosurgical Society
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    • v.30 no.sup1
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    • pp.91-98
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    • 2001
  • Objective : The purpose of this study was to investigate the prognostic factors in patients who suffered an intracerebral hemorrhage(ICH) due to a ruptured middle cerebral artery(MCA) aneurysm. Methods : Among 148 case of ruptured MCA aneurysm, ruptured MCA aneurysm with ICH was compared with ruptured MCA aneurysm alone. According to factors, the prognosis in these two groups was analyzed. Prognosis was evaluated postoperatively by applying Glasgow Outcome Scale(GOS) at discharge. Prognostic factors were evaluated with Chi square test, Mann-Whitney test and ANOVA test with differences being considered significant for value less than 0.05. Results : Ruptured MCA aneurysm alone revealed better consciousness on admission and final outcome than those combined with ICH. Ruptured MCA aneurysm alone showed 74% in H-H grade I, II and 82% in GOS I, II. But ruptured MCA aneurysm with ICH showed 63% in H-H grade IV, V and 52% in GOS IV, V. Age, sex, lesion site, aneurysmal size, temoporary clipping time, interval to operation, operative approach were statistically not significant in prognosis(p>0.05). But H-H grade on admission(p<0.05), complication(esp. cerebral infarction)(p<0.05), preoperative ICH volume and site(p<0.01), preoperative midline shifting(p<0.01), remained ICH volume(p<0.05) showed significance statistically. Conclusion : Prognostic factors are helpful to neurosurgeon to estimate clinical and neurological outcome postoperatively. We suggest that the good prognostic factors in ruptured MCA aneurysm with ICH were good H-H grade on admission, cerebral infarction(-), preoperative ICH volume <25cc, temporal and intrasylvian ICH, preoperative midline shifting <5mm, remained ICH volume <10cc.

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Seral Changes in Environmental Factors and Recovery of Soil Fertility during Abandoned Field Succession after Shifting Cultivation (회전 후 묵밭의 식생 천이 진행에 따른 환경요인의 변화와 토양 비옥도의 회복)

  • Lee, Kyu Song;Joon-Ho Kim
    • The Korean Journal of Ecology
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    • v.18 no.2
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    • pp.243-253
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    • 1995
  • Seral changes in environmental factors and recovery of soil fertility during abandoned field succession after shifting cultivation were investigated in eastern Kangwon-Do, Korea. Relative light intensity of herb and shrub layer decreased gradually until 50 years and increased slightly thereafter. Amount of litter and nutrients derived from it were depicted as a parabola form showing the gradual increment during the first 50 years and slight decrease thereafter. Organic matter, pH value, total-N and Mg of soil were plotted as an early depletion-mid pinnacle form showing the extrems depletion during the first 10 years, abrupt increase in about 20 or 50 years and gradual decrease thereafter. Ca, Al, Mn and Na of soil were depicted as a pinnacle form showing the peak in about 20 or 50 years. Thickness and field capacity of soil increased gradually, but K and total-P did not show any tendency as succession proceeded. The soil fertility, overall capacity of soil nutrients and water for plant growth, was plotted as the early depletion-mid pinnacle form.

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Application of the Polarised Potential-pH Diagrams to Investigate the Role of Sulfate and Dissolved Oxygen in the 3550-ppm NaCl Solution on the Corrosion Behaviour of AISI 316L Stainless Steel

  • Chandra-ambhorn, S.;Kumpai, K.;Muangtong, P.;Wachirasiri, W.;Daopiset, S.
    • Corrosion Science and Technology
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    • v.7 no.1
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    • pp.45-49
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    • 2008
  • The cyclic polarisation technique was applied to determine the corrosion, primary-passivation, transpassive, and protection potential of AISI 316L stainless steels immersed in 3550-ppm NaCl solution containing sulfate in the content up to 3000 ppm. The solutions were kept constant at $27^{\circ}C$ and saturated by laboratory air. The solution pH was varied from 3 to 11. Each type of potentials was plotted in function of pH and linked as lines to determine the different zones in the constructed potential-pH diagram. The predominant regimes of the immunity, general corrosion, perfect passivation, imperfect passivation, and pitting corrosion were determined based on those lines of potentials. Comparing to the potential-pH diagram of specimens immersed in the aerated and deaerated 3550-ppm NaCl solutions, the addition of 3000-ppm $Na_2SO_4$ to these solutions increased the overall, perfect and imperfect, passivation regime by shifting the transpassive-potential line to the noble direction. However, it also widened the imperfect passivation area. The addition of $Na_2SO_4$ did not significantly affect the corrosion potential. It was found that the dissolved oxygen tends to negatively shift the transpassive-potential and protection-potential lines at all studied pH. The considerable effect of dissolved oxygen on corrosion and primary-passivation potentials could not be observed.

Production of a Fibrinolytic Enzyme in Bioreactor Culture by Bacillus subtilis BK-17

  • Lee, Jin-Wook;Park, Sung-Yurb;Choi, Won-A;Lee, Kyung-Hee;Jeong, Yong-Kee;Kong, In-Soo;Park, Sung-Hoon
    • Journal of Microbiology and Biotechnology
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    • v.9 no.4
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    • pp.443-449
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    • 1999
  • Bacillus subtilis BK-17 which produces a novel protease with fibrinolytic activity was isolated from soybean paste. Bioreactor production of the enzyme was studied in order to optimize fermentation conditions such as medium concentration, pH, agitation speed, and temperature. Under most cultural conditions, enzyme production initially began when the cell growth stopped. The onset of the enzyme production was indicated by rapid increase in both dissolved oxygen (DO) and pH. Two- to three-times more concentrated medium than the flask optimum medium yielded higher enzyme production in the bioreactor fermentation. When the medium pH was controlled constant, pH 6.5 exhibited the highest activity in the range of 6.0 to 7.5, but the activity was similar to the case when the pH was initially adjusted to 7.5 and subsequently maintained within a relatively wide range of 6.4 to 7.8. Agitation speed did not affect the enzyme production with an exception of DO reaching zero. Fermentation time was reduced when temperature increased within the range of $25^{\circ}C$ to$37^{\circ}C$. However, the highest activity, along with the slow decrease of the enzymatic activity after reaching the maximum value, was observed at $25^{\circ}C$. By shifting the temperature from $37^{\circ}C$ to $25^{\circ}C$immediately after DO reached the minimum level, the high enzyme production of 1,100 U/ml along with the short fermentation period of 13 h could be obtained.

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