• Title/Summary/Keyword: changes of the pH

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Effects of garlic addition on lipid oxidation of ground pork during storage (마늘의 첨가가 분쇄돈육의 지질 산화에 미치는 영향)

  • 변평화;정재홍;김우정;윤석권
    • Korean journal of food and cookery science
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    • v.17 no.2
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    • pp.117-122
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    • 2001
  • Ground fresh garlic and 50% ethanol garlic extracts were added into ground porks in order to investigate their effects on pH, peroxide and TBA values of ground porks during storage at 4$\^{C}$. The grounded porks tested were devided into two groups of fresh and heated forks at 100$\^{C}$ for 10 minutes. A significant control effect of ground garlic and extracts was found on peroxide and TBA values during storage, particularly for those added with 20% ground garlic and 10% garlic extracts. The effects were maximum after storage of 4-6 days and then decreased thereafter The pH was generally decreased until 6 days followed by the increase. Addition of garlic and garlic extracts caused a little increase in pH and the pH changes were less than the changes of control. Eventhough the effects of garlic on pH, peroxide and TBA values were similar for both heated and fresh pork, heat treated one showed more changes than fresh pork.

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Blood haematology, muscle pH and serum cortisol changes in pigs with different levels of drip loss

  • Koomkrong, Nunyarat;Boonkaewwan, Chaiwat;Laenoi, Watchara;Kayan, Autchara
    • Asian-Australasian Journal of Animal Sciences
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    • v.30 no.12
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    • pp.1751-1755
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    • 2017
  • Objective: An experiment was conducted to study the blood haematology, muscle pH, and serum cortisol changes in pigs with different levels of drip loss. Methods: Two groups (low and high) of 20 animals were selected from 100 pigs based on drip loss. All [$Duroc{\times}(Large\;White{\times}Landrace)$] pigs were slaughtered according to standard slaughtering procedures. At exsanguinations, blood samples were taken for the haematological parameters and serum cortisol analysis. The muscle samples were taken from longissimus dorsi muscle to evaluate the muscle pH and drip loss. Results: Haematological parameters of low drip loss group showed higher content of white blood cells and monocytes than high drip loss group (p<0.05). The low drip loss group had higher muscle pH at 45 min (p<0.05) and 24 h (p<0.001) post-mortem than the high drip loss group. However, there was no significant difference in serum cortisol levels (p>0.05). Conclusion: Drip loss is mainly affected by the muscle pH decline after slaughter and also might be affected by white blood cells and monocytes.

Analysis of the Structure and Stability of Erythropoietin by pH and Temperature Changes using Various LC/MS

  • Chang, Seong-Hun;Kim, Hyun-Jung;Kim, Chan-Wha
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2663-2670
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    • 2013
  • The purpose of stability testing is to provide evidence about how the quality of a drug varies with time under the influence of a variety of environmental factors. In this study, erythropoietin (EPO) was analyzed under different pH (pH 3 and pH 9) and temperature ($25^{\circ}C$ and $40^{\circ}C$) conditions according to current Good Manufacturing Practice (cGMP) and International Conference on Harmonisation (ICH) guidelines. The molecular weight difference between intact EPO and deglycosylated EPO was determined by SDS-PAGE, and aggregated forms of EPO under thermal stress and high-pH conditions were investigated by size exclusion chromatography. High pH and high temperature induced increases in dimer and high molecular weight aggregate forms of EPO. UPLC-ESI-TOF-MS was applied to analyze the changed modification sites on EPO. Further, normal-phase high-performance liquid chromatography was performed to identify proposed glycan structures and high pH anion exchange chromatography was carried out to investigate any change in carbohydrate composition. The results demonstrated that there were no changes in modification sites or the glycan structure under severe conditions; however, the number of dimers and aggregates increased at $40^{\circ}C$ and pH 9, respectively.

Phase stability of TiO2 synthesized by Sol-gel Method at various pH and calcination temperatures (졸-겔 방법으로 합성된 TiO2 상안정성에 대한 pH 및 열처리 온도의 영향)

  • Lee, Jae-Yeon;Kim, Yong-Jin;Kim, Dae-Sung;Shin, Hyo-Soon;Nahm, Sahn;Chun, Myoung-Pyo
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.31 no.4
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    • pp.166-173
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    • 2021
  • The rutile phase of TiO2 forms a stable phase at high temperatures compared to anatase phase, but the stable temperature range of anatase changes depending on the synthesis conditions. In this study, nano-sized TiO2 was synthesized by the Sol-gel method using TiOSO4 and a mixed solvent of ethanol and distilled water, and the phase change of anatase and rutile according to pH and heat treatment temperature was investigated. Changes in the ratio of anatase and rutile were observed by changing the pH (3, 5, 7, 9) and heat treatment temperature (500, 600, 700, 800, 900℃) conditions of the prepared TiO2. As a result of observing these changes through XRD and FE-SEM analysis, anatase TiO2 at 500℃ and rutile TiO2 at 900℃ were observed. According to the pH, at these intermediate temperatures of 600, 700 and 800℃, the ratio of anatase and rutile changes. At 700℃, it was concluded that pH = 3~5 had a larger ratio of anatase TiO2, and pH = 7~9 had a larger ratio of rutile TiO2.

Attenuation of Extracellular Acidic pH-induced Cyclooxygenase-2 Expression by Nitric Oxide

  • Cha, Seok Ho;Park, Ji Eun;Kwak, Jin-Oh;Kim, Hyun-Woo;Kim, Jong Bong;Lee, Kwang Youn;Cha, Young-Nam
    • Molecules and Cells
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    • v.19 no.2
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    • pp.232-238
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    • 2005
  • Corneal endothelial cells play an important role in maintaining the transparency and ionic balance of the cornea. Inflammation causes many changes in the intracellular and extracellular environment of the cornea, including acidosis. We examined the relationship between changes in extracellular pH and expression of cyclooxygenase-2 in cultured bovine corneal endothelial cells. When extracellular pH ($[pH]_o$) was reduced to pH 6.4, COX-2 mRNA increased, with a peak at 2 h. This was blocked by pretreatment with actinomycin D and incubation with spermine NONOate (SPER/NO, a nitric oxide donor). Exposure to the $H^+$ ionophore, carbonyl cyanide m-chlorophenylhydrazone (CCCP), also raised COX-2 mRNA levels. CCCP-induced COX-2 mRNA expression was also reduced by SPER/NO. These results were confirmed immuno-cytochemically. These data demonstrate that COX-2 expression is stimulated by the lowering of extracellular pH that could result from bacterial infection, and that this is countered by over-production of nitric oxide, which could also result from bacterial infection.

Changes of the Physico-chemical Characteristics of Venison Extracts during Chilling Storage (냉장중 사슴육 증탕액의 이화학적 특성의 변화)

  • 박창일;김영직
    • Journal of the East Asian Society of Dietary Life
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    • v.10 no.4
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    • pp.298-304
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    • 2000
  • This experiment was carried out to investigate the changes in pH, proximate composition, pH, VBN, TBA, minerals, and fatty acid of venison extracts, from three slaughtered deers with 180~210 kg live weight (♀, Elk deer, 28~30 months of age) at 4$^{\circ}C$. Proximate composition was not affected by storage periods. The pH, VBN, and TBA ranged from 4.60~4.62, 13.52~15.75 mg%, and 0.20~0/81mg/kg. respectively. The pH, VBN, and TBA gradually increased during storage period (p<0.050. Among minerals, K, P, Na, Mg, and Ca were major mineral contents and the Ca, mg, Na contents significantly decreased (p<0.05) according to the storage period. The major fatty acid found in venison extracts were oleic acid, palmitic acid, stearic acid, linoleic acid. Oleic acid, linolenic acid, and arachidonic acid decreased during storage, but palmitic acid, heptadeanonic acid, and stearic acid increased during the storage. U/S (unsalturated fatty acid/saturated fatty acid) ratio tended to decrease during the storage.

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pH Response Pathways in Fungi: Adapting to Host-derived and Environmental Signals

  • Selvig, Kyla;Alspaugh, J. Andrew
    • Mycobiology
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    • v.39 no.4
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    • pp.249-256
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    • 2011
  • Microorganisms are significantly affected when the ambient pH of their environment changes. They must therefore be able to sense and respond to these changes in order to survive. Previous investigators have studied various fungal species to define conserved pH-responsive signaling pathways. One of these pathways, known as the Pal/Rim pathway, is activated in response to alkaline pH signals, ultimately targeting the PacC/Rim101 transcription factor. Although the central signaling components are conserved among divergent filamentous and yeast-like fungi, there is some degree of signaling specificity between fungal species. This specificity exists primarily in the downstream transcriptional targets of this pathway, likely allowing differential adaptation to species-specific environmental niches. In this review, the role of the Pal/Rim pathway in fungal pH response is discussed. Also highlighted are functional differences present in this pathway among human fungal pathogens, differences that allow these specialized microorganisms to survive in the various micro-environments of the infected human host.

Chemical cleaning effects on properties and separation efficiency of an RO membrane

  • Tu, Kha L.;Chivas, Allan R.;Nghiem, Long D.
    • Membrane and Water Treatment
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    • v.6 no.2
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    • pp.141-160
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    • 2015
  • This study aims to investigate the impacts of chemical cleaning on the performance of a reverse osmosis membrane. Chemicals used for simulating membrane cleaning include a surfactant (sodium dodecyl sulfate, SDS), a chelating agent (ethylenediaminetetraacetic acid, EDTA), and two proprietary cleaning formulations namely MC3 and MC11. The impact of sequential exposure to multiple membrane cleaning solutions was also examined. Water permeability and the rejection of boron and sodium were investigated under various water fluxes, temperatures and feedwater pH. Changes in the membrane performance were systematically explained based on the changes in the charge density, hydrophobicity and chemical structure of the membrane surface. The experimental results show that membrane cleaning can significantly alter the hydrophobicity and water permeability of the membrane; however, its impacts on the rejections of boron and sodium are marginal. Although the presence of surfactant or chelating agent may cause decreases in the rejection, solution pH is the key factor responsible for the loss of membrane separation and changes in the surface properties. The impact of solution pH on the water permeability can be reversed by applying a subsequent cleaning with the opposite pH condition. Nevertheless, the impacts of solution pH on boron and sodium rejections are irreversible in most cases.

A Study on the Influence of Fermented Milk on Oral Ecology - The influence of fermented milk on salivary S. mutans, lactobacilli, pH, and viscosity (유산균 발효유가 구강 생태에 미치는 영향에 관한 연구 - 유산균 발효유가 타약내의 Streptococcus mutans와 lactobacilli 수, 타액 점조도 및 pH에 미치는 영향)

  • Sung-Woo Lee
    • Journal of Oral Medicine and Pain
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    • v.18 no.1
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    • pp.83-96
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    • 1993
  • Even though the increasing interest in fermented milk, the information on the influence of fermented milk on oral health in literature is sparce. We have investigated the effect of fermented milk on saliva. Thirty-three healthy unmedicated subjects at the age of their twenties were included in this study and divided into control, fermented milk, and milk groups. And, the experiment period was 70 days. The authors examined the number of salivary S.mutans, Lactobacilli, pH, and viscosity at the beginning of the experiment. And, we investigated the changes of the these factors at 10,40, and 70 days after. The authors came to the following conclusions The obtined results were as follows : 1. There were no significant changes in the numbers of saliary S. mutans in the control, fermented milk, andmilk groups through the experimental period. 2. There was no significant change in the number of salivary lactobacilli in the fermented milk group throiugh the experimental period. 3. There was a decrease in salivary pH after 40 and 70 days in fermented milk group. 4. There were no significant changes in the values of salivary viscosity at a low shear rate in all groups, but there were increases in these values at a high shear rate in the fermented milk and milk groups through the experimental period.

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Changes in the Water-Holding Capacity Extractability of Proteins and pH Value of Ovine Muscle During Storage (저장중면양근육내(貯藏中緬羊筋肉內)에서의 보수성(保水性), 단백질추출성(蛋白質抽出性) 및 pH의 변화(變化))

  • Chae, Young-Seok
    • Applied Biological Chemistry
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    • v.21 no.2
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    • pp.109-111
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    • 1978
  • This study was undertaken in order to observe the differences of the changes in the water-holding capacity (WHC), extractability of proteins (EP) and pH value of ovine muscle during storage. WHC decreased gradually after slaughter, reached to minimum at about 2-4hr after death as well as that of pH value and then these were recovered along with the progress of the storage. The same tendency was observed in EP but the degree of the changes in pH value up to 6hr after slaughter was more rapid this that of WHC and EP. After the fourth day, the rate of recovery in WHC, EP and pH value in ovine muscle during storage showed similar pattern.

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