• Title/Summary/Keyword: h-stability

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Investigation of muscle-specific beef color stability at different ultimate pHs

  • Wu, Shuang;Han, Jina;Liang, Rongrong;Dong, Pengcheng;Zhu, Lixian;Hopkins, David L.;Zhang, Yimin;Luo, Xin
    • Asian-Australasian Journal of Animal Sciences
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    • v.33 no.12
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    • pp.1999-2007
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    • 2020
  • Objective: This study was aimed to investigate the muscle-specific beef color stability at normal and high ultimate pHs. Methods: The impact of muscle (Longissimus lumborum [LL] vs psoas major [PM]) and pH (normal ultimate pH [Np] vs high pH dark cutting beef [Hp]) on color stability, indicated by basic color traits, metmyoglobin reducing activity (MRA) and oxygen consumption (OC), as well as the lipid oxidation, were determined over 7 days of display at 4℃. Results: Hp-LL had the highest pH (6.92), followed by Hp-PM (6.01), Np-PM (5.76), and Np-LL (5.52). Hp-LL had increased (p<0.05) a, chroma and % oxymyoglobin during display. Hp-LL also had the highest metmyoglobin (MMb) reducing activity and OC among all the samples, thus, the greatest color stability, although very dark throughout storage, with lowest values for lightness (L) and yellowness (b). Np-LL also exhibited relatively high color stability, as a result of its lower % MMb and OC and higher MRA than psoas muscle samples. The 0.2 unit difference of the pH between Hp and Np psoas muscle, resulted in the difference of the color intensity, not the color stability. Interestingly, high pH psoas muscle (Hp-PM) did not have better color stability than Np-PM, and in fact had lower color stability than even Np-LL. The similar level of OC and lipid oxidation cannot explain the difference in color stability between Hp-PM and Np-LL. Conclusion: The Hp does not always show better color stability compared with Np beef, which depends on the muscle type. The balance of MRA and OC is important to keep the color in great intensity and stability in the meantime.

A Stability of Mebendazole in Suspensions (현탁액중 Mebendazole의 안정성)

  • 한관섭;용군호;김길수;허영헌
    • YAKHAK HOEJI
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    • v.20 no.1
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    • pp.27-31
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    • 1976
  • The stability of a newly introduced anthelmintic, mebendazole, in sweetened and aqueous suspension was tested by the accelerated temperature method and the effect of pH on the stability of mebendazole was studied. Mebendazole in aqueous and sweetened suspension was very stable at the pH range from 4 to 8.

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Studies on Characteristics and Stability of Anthocyanin Pigment Extracted from Korean Purple - Fleshed Potatoes (한국산 유색감자 색소의 특성 및 안정성에 관한 연구)

  • Park, Hong-Ju;Jeon, Tae-Woog;Lee, Sung-Hyeon;Cho, Yong-Sik;Cho, Soo-Muk;Chang, Kyu-Seob
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.9
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    • pp.1544-1551
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    • 2004
  • Effects of pH, sugar, ascorbic acid, organic acids and light sources on the stability of anthocyanin pigment extracted from Korean purple-fleshed potatoes (PL-6, PL-28, PL-31 and Jasim) were studied. The pH had remarkable influence on the color stability of anthocyanin pigment. With increasing pH, the color gradually fades as colorless pseudobases are formed. In acidic pH, anthocyanin was stable, but with increasing pH the color gradually changed to colorless. The addition of sugar decrease in color stability of the pigment during storage period. The most of organic acids, such as a tartaric, citric and succinic acids, were found to improve the stability of the pigment, while malic and malonic acid reduced the stability of the pigment. The addition of ascorbic acid considerable decreased in anthocyanin pigment stability, but the effect was not decreased by adding thiourea. The effect of light sources such as a darkroom, a fluorescent light, and sunlight, reduced gradually the stability of anthocyanin pigment. Therefore the pigment degradation could be minimized by shielding the light from the pigment.

H Control for Networked Control Systems with Randomly Occurring Packet Losses and Disturbances (임의적 패킷 손실과 외란입력을 고려한 네트워크 제어 시스템의 H 제어기 설계)

  • Lee, Tae H.;Park, Ju H.;Kwon, Oh-Min;Lee, Sang-Moon
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.62 no.8
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    • pp.1132-1137
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    • 2013
  • This paper considers the $H_{\infty}$ control problem for networked control systems(NCSs). In order to solve the problem which comes from discontinuous control signal in NCSs, an approach that discontinuous control signals treat time-varying delayed continuous signals is applied to achieve $H_{\infty}$ stability of NCSs. In addition, randomly occurring packet losses and disturbances are considered by introducing stochastic variables with Bernoulli distribution. Based on Lyapunov stability theory, a new stability condition is obtained via linear matrix inequality formulation to find the $H_{\infty}$ controller which achieves the mean square stability of NCSs. Finally, the proposed method is applied to a numerical example in order to show the effectiveness of our results.

Emulsion Properties of Small Red Bean Protein Isolates (분리 팥 단백질의 유화특성에 관한 연구)

  • Kim, Hyon-Jung;Sohn, Kyung-Hee;Park, Hyun-Kyung
    • Korean journal of food and cookery science
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    • v.6 no.4 s.13
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    • pp.9-14
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    • 1990
  • The emlsifying properties of small red bean protein isoates were evaluated through their emulsion capacity and stability of the resulting emulsions. The influence of pH, Sodium Chloride and heat treatment on the efficiency of small red bean protein isolates as emulsifying agents was studied. The surface hydrophobicity (So) of small red bean protein islates also examined. The results were obtained as follows; 1. The emusion capacity of small red bean protein isolates was high at pH 11, low at pH 3 and decreased by heat treament. With addition of NaCl, emulsion capacity decreased steadily and showed lowest value when 0.2M NaCl was added. 2. The emulsion stability at pH 4.5 and heat treatment over $60^{\circ}C$ decreased emulsion stability at pH 4.5. When NaCl was added, emulsion stability was generally increased. 3. The surface hydrophobicity of small red bean protein isolates showed the highest value at pH 3 and lowest at pH 11 and increased as the heating temperature increased When 0.2 M NaCl was added, surface hydrophobicity also increased at pH 4.5.

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Influence of Various Cyclodextrins on the Stability of Hydrocortisone 17-Butyrate in Aqueous Solution

  • Chun, In-Koo;Kim, Bo-Young
    • Archives of Pharmacal Research
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    • v.15 no.2
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    • pp.176-183
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    • 1992
  • The stabilizing effects of $\alpha$-$\beta$-$\gamma$- and dimethyl-$\beta$-cyclodextrins $(\alpha$-, $\beta$-, $\gamma$- and DM-$\beta-$-CyDs) on the degradation of hydrocortisone 17-butyrate (HC-17B) in aqueous solution was investigated. Hc-17B underwent a facile hydroxide ion-catalyzed rearrangement to the less active 21-butyrate ester by the apparent first-order kinetics, and maximum stability of HC-17B was obtained at around pH 4.0. The stability of HC-17B was increased by inclusion complexation with $\alpha$-, $\gamma$- and DM-$\beta$-CyD in the pH range of 2.0-8.0 examined, whereas $\beta$-CyD accelerated the degradation of HC-17B at the pH higher than 5.0. The effects of ionic strength, solvent, temperature and CyD concentration were also investigated. Stability constants and apparent degradation rate constants of HC-17B-$\gamma$-CyD and HC-17B-DM-$\beta$-CyD complexes were determined kinetically on the basis of 1:1 complexation. The results suggested that the inclusion complexation with $\gamma$-CyD or DM-$\beta$-CyD was most useful means to enhance the stability of the steroid.

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