• Title/Summary/Keyword: and peroxide values

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Nitrite-Scavenging and Antioxidant Activities of Wood Vinegar (목초액의 아질산염 소거 및 항산화 활성)

  • 정창호;심기환
    • Food Science and Preservation
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    • v.9 no.3
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    • pp.351-355
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    • 2002
  • The purpose of this study was to investigate the nitrite scavenging, eletron donating activity and antioxidant activity of wood vinegar on soybean oil. Wood vinegar was added to soybean oil in the quantities of 0.5, 1 and 5%. Nitrite scavenging effect of all concentrations diminished at higher pH, while in the case of pH 1.2, it showed a nitrite scavenging effect of more than 80% at concentration above of 100 ㎕/mL. The electron donating activity was about 80% at concentration above of 50 ㎕/mL. Soybean oil without the addition of wood vinegar was used as a control. The oxidation of these samples was determined by measuring the peroxide value(POV), thiobarbituric acid(TBA) value and acid value(AV). When wood vinegar was added 1 and 5%, the peroxide value wag lower than both the control and 0.1% BHT. TBA value were in the 5% wood vinegar tallowed by 1% wood vinegar, 0.1% BHT, 0.5% wood vinegar and the control, respectively. The results showed that the acid values were lowest in 5% wood vinegar, followed by the 0.1% BHT, 1% wood vinegar, 0.5% wood vinegar and finally the control.

Oxidative Stability of Tallow Heated by Different Frying Conditions (튀김조건에 따른 가열 우지의 산화안정성)

  • 장영상;양주홍
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.331-337
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    • 2001
  • The oxidative stability of tallow heated was studied by different frying condition (temperature 130, 150, and 180$^{\circ}C$;heating time, each 10hours per day, total 240hrs). Changes of physicochemical parameters such as acid value, peroxide value, iodine value, dielectric constant, content of polar components and polymer, refractive index, smoke point, viscosity and color changes in tallow heated were also measured. Acid value, dielectric constant, refractive index, viscosity, and content of polar component and polymer increased as the tallow was heated longer, whereas iodine value and smoke point decreased and peroxide value was increased and decreased repeatedly. These parameters changed to a greater extent as the heating temperature went up. The color became darkened with the increase of red and yellow values during heating. The decree of coloration was proportional to heating temperature.

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Studies on the Nutritional Composition and Storage Stability of Weaning Food Manufactured in Korea (시판 초기 이유식의 영양성분 및 저장 안정성에 관한 연구)

  • 김동한;이성갑;손종연
    • The Korean Journal of Food And Nutrition
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    • v.16 no.1
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    • pp.1-6
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    • 2003
  • This study was attempted to analyze nutritional composition and nutritional balance of domestic and affiliated company of foreign group weaning food. The results were as follows: The proximate compositions were 61%∼70% carbohydrate, 14%∼16% protein, 2.5%∼3.2% ash and 8%∼15% lipid. Leucine content was the highest among all essential amino acids in all test weaning foods. The P/S and linoleic acid / linolenic acid ratio of domestic weaning foods were higher than those of affiliated company of foreign group weaning food. The peroxide values of H, M, S and N product were 13.9 meq/kg oil, 1.1 meq/kg oil, 5.4 meq/kg oil and 14.8 meq/kg oil, respectively.

Quality Characteristics of Cookies Made with Flaxseed Powder (아마씨 가루를 첨가한 쿠키의 품질특성)

  • Kim, Su-Yean;Chung, Hai-Jung
    • Food Engineering Progress
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    • v.15 no.3
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    • pp.235-242
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    • 2011
  • This study was conducted to investigate the quality characteristics of cookies added with different levels of flaxseed powder. Cookies were prepared with four different levels (0%, 6%, 12% and 18%) of flaxseed powder and the physicochemical properties were examined. The pH of cookie dough was higher in cookies containing flaxseed powder. The spread factor of control cookie was lower than that of cookies containing 6%, 12% and 18% of flaxseed powder. The incorporation of flaxseed powder in cookies lowered lightness and yellowness but increased redness values. Rheology testing showed that cookies with 6%, 12% and 18% flaxseed powder had significantly lower hardness value than control cookies (p < 0.05). Consumer acceptance test revealed that overall preference score was the highest in cookies containing 12% flaxseed powder. During storage at $55^{\circ}C$ for 60 days, peroxide value increased until 30 days of storage and decreased thereafter, while acid value steadily increased and there was no significant difference in peroxide value and acid value between control cookies and flaxseed added cookies.

A study on the Ozone oxidation of Diesel-contaminated Groundwater (디젤로 오염된 지하수의 오존산화처리에 대한 연구)

  • 권충일;공성호;김무훈
    • Journal of Korea Soil Environment Society
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    • v.5 no.3
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    • pp.3-15
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    • 2001
  • The ozone kinetics including ozone auto-decomposition. effect of pH, and solubility were investigated. Diesel decomposition process including TCE & PCE decomposition. effect of hydroxyl radical scavenger, effect of pH, and ozone/$H_2O$$_2$by ozonation process were also examined using deionized water, simulated groundwater. and actual groundwater. Reactions with deionized water and groundwater both stowed the second-order reaction rates, and the reaction rate was much higher in groundwater (half-life of 14.7 min) than in deionized water (hal(half-life of 37.5 min). The reaction rate was accelerated at high pH values in both waters. The use of ozone showed high oxidation rates of TCE. PCE and diesel. Though hydroxyl radical scavengers existing in groundwater were inhibitors for treating diesel, high pH condition and addition of hydrogen peroxide could accelerate to degrade diesel in groundwater, indicating ozone oxidation process could be applied to treating diesel contaminated-groundwater.

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Analysis of Chemical Composition and Antioxidant Activity of Suaeda japonica (칠면초의 성분 분석 및 추출물의 항산화 효과)

  • Lee, Kyung-Seok;Kim, Ae-Jung;Lee, Ki-Young
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.4
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    • pp.521-526
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    • 2012
  • This study was conducted in order to analyze the ingredients and antioxidant activity of Suaeda japonica (turkey), which is abundantly present in Korea where mud flats are well formed due to the characteristics of halophytes. In the analysis of general composition, contents of carbohydrates, proteins, ash, and moisture were 10.7%, 8.3%, 7.6%, and 72.5% respectively. Among minerals, sodium was measured as 5.4%, which means that most ash was made of sodium. Heavy metal contents of lead, cadmium, arsenic, and mercury were 0.86 ppm, 0.04 ppm, 0.39 ppm, and 0.01 ppm, meaning Suaeda japonica satisfied standard food values. The 70% ethanol extract from Suaeda japonica was evaluated for its free radical scavenging activity and compared with a commercial antioxidant, BHA (butylated hydroxyanisole). As a result, the scavenging activities of hydroxyl radical, hydrogen peroxide, and xanthine oxidase of the extracts were equivalent to 30~50% of that of BHA.

Effect of Temperature on Composition of Monohydroperoxide Isomers Formed in Oxidation of Methyl Linoleate (Methyl Linoleate의 산화중 형성된 Monohydroperoxide 이성체들의 조성에 미치는 온도의 영향)

  • Kim, In-Hwan;Kim, Chul-Jin;Kim, Dong-Hoon
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.440-445
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    • 1996
  • An attempt was made to study the relative composition of Monohydroperoxide isomers of methyl linoleate oxidized to different peroxide values at 60, 90, 120 and $150^{\circ}C$, respectively. HPLC was used to analyze and isolate the monohydroperoxide isomers fractionated by silica gel column after reduction with NaBH.. GC-MS was used to identify four monnhydroperoxide isomers as trimethylsilyl (TMS) in mixtures of oxidized methyl linoleate In the geometrical isomers, the proportions of 9/13-OOH-trans, trant-diene were higher than those of 9/13-OOH-cis, trans-diene at $60^{\circ}C$ and $90^{\circ}C$. However in the initial stage at $150^{\circ}C$, the proportions of 9/13-OOH-cis, trans-diene were slightly higher than those of 9/13-OOH-trans, trans-diene. In case of positional isomers, equal proportions of 9-OOH-10, 12-diene and 13-OOH-9, 11-diene were found in all samples of methyl linoleate oxidized at different temperatures and peroxide levels.

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Comparative Study of Fatty Acid Composition and Characterization of Fixed Oil of Four Peanut Varieties Available in Pakistan

  • Akhtar, Hifza;Hamid, Shahnaz;Khan, Javed Iqbal
    • Natural Product Sciences
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    • v.11 no.4
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    • pp.225-228
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    • 2005
  • four varieties of ground nut (Arechis hypogea) were collected from different areas of Pakistan (Tillagang, Gujar khan, Hanoi and Pipplan) from Punjab province. The oils were extracted for the evaluation of lipid. Physico-chemical values of oils were determined like refractive index, peroxide value, unsaponifiable matter, acid value, iodine value, free fatty acid and ester value. The lipid profile as indicated by GLC showed that Palmitic acid ranged from 8.2-8.8%, proportions of oleic acid and linoleic acid varied from 57.8-59.87% and 22.5-24.1% respectively. Gujar khan variety of peanut has higher % age of oil (56.79). The higher yield of oil in this variety is not at the cost of any nutritional quality of peanut oil.

Neuronal Cytotoxicity of Oxygen Radical in Newborn Mouse Forebrain Culture

  • Lim, Kye-Taek;Park, Seung-Taeck;Choi, Min-Kyu;Chung, Yeun-Tai
    • Toxicological Research
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    • v.11 no.2
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    • pp.187-192
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    • 1995
  • The cytotoxic effects of hydrogen peroxide and neuroprotective effects of a variety of agents were investigated in newborn mouse forebrain tissue culture. In our experiments, oxygen radical was generated enzymatically by glucose oxidase and the values were expressed as a percentage of number of living cells by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Cytotoxicity of oxygen radicals was prevented by catalase and (N, N, N', N', -tetrakis (2-pyridylmethyl) ethylenediamine (TPEN), but N-tetra-ot-butyl-phenylnitrone (PBN), and deferoxamine (DFX), failed to show protective effects against oxygen radicals. Antagonists of the N-methyl-D-aspartate (NMDA) receptor, D-2-amino-5-phosphonovaleric acid (APV), 7-chlorokynurenic acid (CKA), and MK801 (a non-competitive NMDA antagonist) were also not effective in blocking neurotoxicity induced by glucose oxidase generated oxygen radicals.

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Cure Kinetics of a Bisphenol-A Type Vinyl-Ester Resin Using Non-Isothermal DSC

  • Ahn, WonSool
    • Elastomers and Composites
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    • v.53 no.1
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    • pp.1-5
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    • 2018
  • In the current research, the curing kinetics of a mixture system consisting of a Bisphenol-A type vinyl ester resin and styrene monomer was studied. Methylethylketone peroxide and cobalt octoate were used as the polymerization initiator and accelerator respectively. Thermograms with several different heating rates were obtained using non-isothermal differential scanning calorimetry. Activation energy values analyzed by the Flynn-Wall-Ozawa isoconversional method showed a three-step change with conversion ${\alpha}$: a slight decrease initially for ${\alpha}$ < 0.1, a constant value of 47.9 kJ/mol in the range 0.1 < ${\alpha}$ < 0.7, and a slow increase for 0.7 < ${\alpha}$. When assuming a constant activation energy of 47.9 kJ/mol, an autocatalytic model of the Sestak-Berggren equation was considered as the proper mathematical model of the conversion function, indicating an overall order of 1.2.