• Title/Summary/Keyword: soluble stability

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Synthesis and Properties of Novel T-type Nonlinear Optical Polyurethane Containing Tricyanovinylthienyl Group with Enhanced Thermal Stability of Dipole Alignment

  • Cho, You-Jin;Kim, Mi-Sung;Lee, Ju-Yeon
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.424-430
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    • 2011
  • A novel T-type polyurethane 7 containing 1-(2,5-dioxyphenyl)-2-(5-(1,2,2-tricyanovinyl)-2-thienyl)ethenes as NLO chromophores, which constitute part of the polymer backbone, was prepared. Polyurethane 7 is soluble in common organic solvents such as DMF and DMSO. It shows a thermal stability up to $270^{\circ}C$ from TGA thermogram with $T_g$ value obtained from DSC thermogram near $155^{\circ}C$. The second harmonic generation (SHG) coefficient ($d_{33}$) of poled polymer film at 1560 nm fundamental wavelength is $3.56{\times}10^{-9}$ esu. Polymer 7 exhibits a thermal stability even at $5^{\circ}C$ higher than $T_g$, and no significant SHG decay is observed below $160^{\circ}C$, which is acceptable for nonlinear optical device applications.

Immobilization of Keratinase from Aspergillus flavus K-03 for Degradation of Feather Keratin

  • Kim, Jeong-Dong
    • Mycobiology
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    • v.33 no.2
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    • pp.121-123
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    • 2005
  • Extracellular keratinase isolated from Aspergillus flavus K-03 was immobilized on calcium alginate. The properties and reaction activities of free and immobilized keratinase with calcium alginate were characterized. The immobilized keratinase showed proteolytic activity against soluble azo-casein and azo-keratin, and insoluble feather keratin. Heat stability and pH tolerance of keratinase were greatly enhanced by immobilization. It also displayed a higher level of heat stability and an increased tolerance toward alkaline pHs compared with free keratinase. During the durability test at $40^{\circ}C$, 48% of the original enzyme activity of the immobilized keratinase was remained after 7 days of incubation. The immobilized keratinase exhibited better stability, thus increasing its potential for use in industrial application.

The Study on Antioxidation of Retinal (Retinol에 대한 항산화 연구)

  • 조춘구;한창규;홍우진
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.28 no.1
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    • pp.58-70
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    • 2002
  • In an attempt to compare the antioxidation effects of constrain the oxidation and improve the structural stability, retinol and various antioxidants were together encapsulated by liposome. Four water soluble and four oil soluble antioxidants were tested for performance. The influence of tertiary butylhydroquinone(TBHQ), ${\alpha}$-glycosyl rutin(${\alpha}$-G rutin), licorece, pycnogenol as water soluble antioxidants and butylated hydroxytoluene(BHT), ${\alpha}$-lipoic acid, ferulic acid, natural concentrated tooopherol(no-tocopherol) as oil soluble antioxidants on the constraint of oxidation of retinol were investigated. Additional study was conducted to compare the synergic effect of antioxidation for retinol with licorice, pycnogenol, ${\alpha}$-lipoic acid and BHT. All the antioxidant used at the study constrained oxidation of retinol. The effect of antioxidation for retinol increased in order of licorice, pycnogenol, TBHQ, ${\alpha}$-G rutin as water soluble antioxidants and ${\alpha}$-lipoic acid, BHT, no-tocopherol, ferulic acid as oil soluble antioxidants. In conclusion, ${\alpha}$-lipoic acid is more effective retinol antioxidants than BHT. And the combination of ${\alpha}$-lipoic acid and BHT gave best synergic among six combinations.

Characterization of Cooked Meat Models using Grasshopper (Sphenarium purpurascens) Soluble Protein Extracted by Alkalisation and Ultrasound as Meat-Extender

  • Cruz-Lopez, Salvador Osvaldo;Escalona-Buendia, Hector Bernardo;Roman-Guerrero, Angelica;Dominguez-Soberanes, Julieta;Alvarez-Cisneros, Yenizey Merit
    • Food Science of Animal Resources
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    • v.42 no.3
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    • pp.536-555
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    • 2022
  • The most abundant Orthoptera in Mexico is a small grasshopper (Sphenarium purpurascens) which is considered a food source with increased nutritional value due to its high protein content. Insect proteins have gained relevance because of their high potential as gelling, texturing, and extender agents in the food industry. The objective of this study was to evaluate the effect of substituting meat with a soluble protein extract from grasshopper obtained by alkalisation or alkalisation-piezoelectric ultrasound, on the techno-functional, physicochemical, and sensory characteristics of cooked meat models (sausages). The soluble protein was extracted in NaHCO3 pH 8 and a piezoelectric ultrasound 5-mm sonotrode at 20 kHz with 99% amplitude. Different formulations with meat substitution: 0%, 5%, 10%, and 15% were prepared and characterised for their rheological behaviour, emulsion stability, weight loss by cooking, total protein content, colour, and texture. Sensory evaluation was conducted with consumers using a test involving check-all-that-apply and overall liking. The alkalisation-piezoelectric ultrasound method improved the solubility and the techno-functional properties of the soluble grasshopper protein when applied in sausages at maximum levels of 10% meat substitution. The sensory evaluation indicated that the formulation with 5% meat substitution exhibited the same acceptability as the control sample. Given these results, the soluble protein treated with alkalisation and piezoelectric ultrasound could be used as an extender in meat products.

Antioxidative Effect of Ethanol Fraction for Several Korean Medicinal Plant Hot Water Extracts (몇 가지 생약재의 열수 추출물에 대한 Ethanol 분획물의 항산화 효과)

  • 김영언;이영철;김현구;김철진
    • The Korean Journal of Food And Nutrition
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    • v.10 no.2
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    • pp.141-144
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    • 1997
  • The hot water extracts of Paeonia japonica, Paeonia moutan, Eucommia ulmoides, Bupleurum falcatum, Cornus officinalis were freeze dried and dissolved with 70% ethanol. These extracts were fractionated with ethanol soluble fraction(ESF) and ethanol insoluble fraction(EIF). To compare oxidative stability effect of these extracts with that of BHA, linoleic acid with 3,000ppm extracts was incubated at 35$^{\circ}C$. Induction period of BHA was 9 days but that of Paeonia japonica ESF and Scutellaria baicalensis ESF was 12, 9 days respectively. And the higher antioxidant activity was observed for ESF than EIF of these extracts.

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Validation of an Extraction Method for the Determination of Airborne MWFs using Alternative Solvents (대체용매를 이용한 금속가공유 측정방법 타당성 평가)

  • Jeong, Jee Yeon;Baek, Nam Won
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.16 no.2
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    • pp.91-100
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    • 2006
  • The purpose of this study was to validate alternative method by using non-carcinogenic, and less toxic solvents than NIOSH analytical method 5524 for measuring the airborne MWFs in workplaces. In laboratory tests, the ETM solvents(mixture of same volume for ethyl ether, toluene, and ethanol) were selected. The alternative method of analyzing MWFs, referred to as the ETM solvent extraction method, showed 0.04 mg/sample as LOD, and 0.15 mg/sample as LOQ. The analytical precision (pooled CV, coefficient of variation) of the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was 1.5%, 2.0%, 2.6%, 1.6%, respectively, which was similar to the precision (2.6%) of NIOSH analytical method (NIOSH 0500) for total dust. The analytical accuracy by recovery test, spiked mass calculated as extractable mass, was almost 100%. As the result of storage stability test, metalworking fluid samples should be stored in refrigerated condition, and be analyzed in two weeks after sampling. The 95% confidence limit of the estimated total standard error for the ETM solvent extraction method for analyzing the straight, soluble, semisynthetic, and synthetic metalworking fluid was ${\pm}12.6%$, ${\pm}12.5%$, ${\pm}14.0%$, and ${\pm}13.6%$, respectively, which satisfied the OSHA sampling and analytical criteria.

Physicochemical Properties of Soybean Curd Residue Powder by Different Soybean and Drying Methods (콩의 종류와 건조 방법에 따른 비지 분말의 이화학적 특성)

  • Eun Ji Kim;Hee Nam Jung
    • Journal of the Korean Society of Food Culture
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    • v.38 no.5
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    • pp.356-364
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    • 2023
  • This study compared the physicochemical properties of soybean curd residue and black soybean curd residue produced by hot air-drying and freeze-drying. Regardless of drying method, the crude protein, crude ash, crude fiber contents, pH, L, a, b color values and water soluble index were higher in soybean curd residue, whereas total polyphenol contents and antioxidant activity were higher in black soybean curd residue. Significant differences in water absorption index, oil absorption capacity and emulsion activity were observed between soybean curd residue and black soybean curd residue in freeze-drying. On the other hand, the emulsion stability was not significant difference in both hot-air drying and freeze-drying. The crude protein and crude fiber contents of soybean curd residue were not significant difference between hot-air drying and freeze-drying. Freeze-drying resulted in higher crude ash contents, pH, water absorption index, water soluble index, oil absorption capacity, emulsion activity and emulsion stability than hot-air drying. Hot-air drying have caused significantly higher water contents, water activity, total polyphenol contents and antioxidant activity in soybean curd residue than freeze-drying. In conclusion, soybean type and drying methods affect the physicochemical and quality characteristics of soybean curd residue, which could be important factors in the manufacture of processed foods.