Thermal degradation kinetics of bioactive compounds from black rice flour ( Oryza sativa L.) extracts

2016 ◽  
Vol 71 ◽  
pp. 160-166 ◽  
Author(s):  
Carmen Bolea ◽  
Mihaela Turturică ◽  
Nicoleta Stănciuc ◽  
Camelia Vizireanu
Keyword(s):  
Oryza Sativa ◽  
Thermal Degradation ◽  
Bioactive Compounds ◽  
Oryza Sativa L ◽  
Degradation Kinetics ◽  
Rice Flour ◽  
Thermal Degradation Kinetics ◽  
Black Rice ◽  
Kinetics Of

scholarly journals Process-Structure-Function in Association with the Main Bioactive of Black Rice Flour Sieving Fractions

Foods ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 131 ◽  
Author(s):  
Bolea ◽  
Grigore-Gurgu ◽  
Aprodu ◽  
Vizireanu ◽  
Stănciuc
Keyword(s):  
Thermal Degradation ◽  
Structure Function ◽  
Conformational Changes ◽  
Degradation Kinetics ◽  
Rice Flour ◽  
Biologically Active ◽  
Thermal Degradation Kinetics ◽  
Black Rice ◽  
Food Ingredient ◽  
Process Structure

The aim of this work was to advance knowledge on the potential use of black rice different sieving fractions for various functional applications, through proximate analysis, thermal degradation kinetics of phytochemical and characterization of the thermal behavior of the main proteins, from the perspectives of their use as a food ingredient. The results indicated that the thermal degradation of phytochemicals followed a first-order reaction kinetics for all the tested fractions. The temperature-dependent degradation was adequately modeled according to the Arrhenius equation. The calculated activation energies (Ea) and k values were different among the four studied parameters. The kinetic parameters depended on the grinding and sieving degree, the anthocyanins being the most thermolabile compounds, thus affecting the antioxidant activity. Three protein fractions were identified by electrophoresis with different molecular weight, such as albumin, globulin, and glutelin. The fluorescence spectroscopy experiments revealed the sequential character of the heat-induced conformational changes, different molecular events being suggested, such as folding in the lower temperature range and unfolding at higher temperature. The significance of the study is evidenced by the need to identify and advance the process-structure-function relationships for various biologically active compounds from the perspective of obtaining food or ingredients nutritionally optimized.

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.

scholarly journals Thermal Degradation Kinetics of Sugarcane Bagasse and Soft Wood Cellulose

Materials ◽  
2017 ◽  
Vol 10 (11) ◽  
pp. 1246 ◽  
Author(s):  
Samson M. Mohomane ◽  
Tshwafo E. Motaung ◽  
Neerish Revaprasadu
Keyword(s):  
Thermal Degradation ◽  
Sugarcane Bagasse ◽  
Degradation Kinetics ◽  
Thermal Degradation Kinetics ◽  
Wood Cellulose ◽  
Kinetics Of
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