Degradation Kinetics of Catechins in Green Tea Powder: Effects of Temperature and Relative Humidity

2011 ◽  
Vol 59 (11) ◽  
pp. 6082-6090 ◽  
Author(s):  
Na Li ◽  
Lynne S. Taylor ◽  
Lisa J. Mauer
Keyword(s):  
Relative Humidity ◽  
Green Tea ◽  
Degradation Kinetics ◽  
Green Tea Powder ◽  
Effects Of Temperature ◽  
Kinetics Of

scholarly journals Degradation Kinetics of Anthocyanins in Shalgam Beverage

2019 ◽  
Vol 7 (2) ◽  
pp. 282
Author(s):  
Adnan Bozdoğan ◽  
Kurban Yaşar
Keyword(s):  
Activation Energy ◽  
Reaction Kinetics ◽  
Half Life ◽  
Degradation Kinetics ◽  
Production Method ◽  
Order Reaction ◽  
Different Temperatures ◽  
Traditional Production ◽  
Effects Of Temperature ◽  
Kinetics Of

This research was performed to elucidate the effects of temperature on the degradation kinetics of anthocyanins in shalgam beverage. Shalgam beverage was produced according to traditional production method. Then, it was kept at three different temperatures (65°C, 75°C, and 85°C) for 12 hours, and the relevant quantities of anthocyanins were determined thereafter. The research revealed that degradation of the anthocyanins was well described with a 1st-order reaction kinetics model and the R2 values varied in the range of 0.9059-0.9715. Activation energy of the reaction was determined to be 48537 Joule/mole. The half-lives of anthocyanins at 65°C and 75° C, and 85°C were found to be 138.63, 136.72, and 51.57, respectively. Compared the half-life periods at different temperatures, anthocyanins were found to be more resistant at 65°C and 75°C than at 85°C.

scholarly journals Studies of Degradation Kinetics of a 5-HT3 Antagonist, Ramosetron Hydrochloride: Effects of Temperature

2018 ◽  
Vol 17 (2) ◽  
pp. 167-173
Author(s):  
Md Mokaram Hossain ◽  
Reza Ul Jalil ◽  
Mohammad A Rashid
Keyword(s):  
Reaction Rate ◽  
Arrhenius Equation ◽  
Degradation Kinetics ◽  
First Order ◽  
Reaction Rate Constants ◽  
First Order Kinetics ◽  
Antiemetic Activity ◽  
Effects Of Temperature ◽  
Kinetics Of ◽  
Subtype 3

Ramosetron hydrochloride is the hydrochloride salt of ramosetron, a selective serotonin (5-HT3) receptor antagonist with potential antiemetic activity. Upon administration, ramosetron selectively binds to and blocks the activity of 5-HT subtype 3 (5-HT3) receptors located in the vagus nerve terminal and the vomiting center of central nervous system (CNS), suppressing chemotherapy-induced nausea and vomiting. Degradation of Ramosetron HCl was conducted with 0.1N NaOH at 60°C, 70°C and 80°C to study the reaction kinetics. The reaction rate constants (k) for degradation at 60°C, 70°C and 80°C were -2.2680 molL-1s-1 , -3.3714 molL-1s-1 and -5.3686 molL-1s-1 for zero order and -1.05 x 10-2s-1, -1.60 x 10-2s-1 and -2.70 x 10-2s-1 for first order kinetics, respectively. The activation energy of Ramosetron HCl was found as 10.05 kcalmol-1 by using Arrhenius equation. Dhaka Univ. J. Pharm. Sci. 17(2): 167-173, 2018 (December)

Effect of Relative Humidity and Storage Temperature on the Quality of Green Tea Powder

2009 ◽  
Vol 38 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Jung-Min Lee ◽  
Sang-Wook Lim ◽  
Sung-Hwan Cho ◽  
Sung-Gil Choi ◽  
Ho-Jin Heo ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Green Tea ◽  
Storage Temperature ◽  
Green Tea Powder ◽  
And Storage

scholarly journals Degradation Kinetics of Humic acid in Aqueous Solution by Ozonation Treatment under Different Parameter Conditions

2020 ◽  
Vol 596 ◽  
pp. 012010
Author(s):  
Zafirah Mahyun ◽  
Noor Fazliani Shoparwe ◽  
Ahmad Zuhairi Abdullah ◽  
Abdul Latif Ahmad ◽  
Mardawani Mohamad ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Humic Acid ◽  
Degradation Kinetics ◽  
Kinetics Of

scholarly journals Thermal Degradation Kinetics and Modeling Study of Ultra High Molecular Weight Polyethylene (UHMWP)/Graphene Nanocomposite

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1597
Author(s):  
Iman Jafari ◽  
Mohamadreza Shakiba ◽  
Fatemeh Khosravi ◽  
Seeram Ramakrishna ◽  
Ehsan Abasi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Molecular Weight ◽  
Thermal Degradation ◽  
High Molecular Weight ◽  
Degradation Kinetics ◽  
Graphene Nanosheets ◽  
Thermal Degradation Kinetics ◽  
Graphene Nanocomposites ◽  
Kinetics Of ◽  
Ultra High Molecular Weight

The incorporation of nanofillers such as graphene into polymers has shown significant improvements in mechanical characteristics, thermal stability, and conductivity of resulting polymeric nanocomposites. To this aim, the influence of incorporation of graphene nanosheets into ultra-high molecular weight polyethylene (UHMWPE) on the thermal behavior and degradation kinetics of UHMWPE/graphene nanocomposites was investigated. Scanning electron microscopy (SEM) analysis revealed that graphene nanosheets were uniformly spread throughout the UHMWPE’s molecular chains. X-Ray Diffraction (XRD) data posited that the morphology of dispersed graphene sheets in UHMWPE was exfoliated. Non-isothermal differential scanning calorimetry (DSC) studies identified a more pronounced increase in melting temperatures and latent heat of fusions in nanocomposites compared to UHMWPE at lower concentrations of graphene. Thermogravimetric analysis (TGA) and derivative thermogravimetric (DTG) revealed that UHMWPE’s thermal stability has been improved via incorporating graphene nanosheets. Further, degradation kinetics of neat polymer and nanocomposites have been modeled using equations such as Friedman, Ozawa–Flynn–Wall (OFW), Kissinger, and Augis and Bennett’s. The "Model-Fitting Method” showed that the auto-catalytic nth-order mechanism provided a highly consistent and appropriate fit to describe the degradation mechanism of UHMWPE and its graphene nanocomposites. In addition, the calculated activation energy (Ea) of thermal degradation was enhanced by an increase in graphene concentration up to 2.1 wt.%, followed by a decrease in higher graphene content.

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