Kinetics of degradation of ascorbic acid by cyclic voltammetry method
| Autor: | Veselinka Grudić, L Vesna Vukasinovic-Pesic, Z Nada Blagojevic, R Snezana Brasanac |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Arrhenius equation
Chemistry General Chemical Engineering First-order reaction Kinetics lcsh:TP155-156 Activation energy Ascorbic acid Redox cyclic voltammetry green peppers symbols.namesake Reaction rate constant kinetics symbols Organic chemistry ascorbic acid Cyclic voltammetry lcsh:Chemical engineering lcsh:HD9650-9663 Nuclear chemistry lcsh:Chemical industries |
| Zdroj: | Chemical Industry and Chemical Engineering Quarterly, Vol 21, Iss 2, Pp 351-357 (2015) |
| ISSN: | 2217-7434 1451-9372 |
| Popis: | Cyclic voltammetry was used to examine the kinetics of degradation of ascorbic acid (AA) at different temperatures. It has been shown that the reduction of the concentration of AA in all temperatures follow the kinetics of the first order reaction. The rate constant of the oxidation reaction increases with temperature as follows: 5x10-5; 2x10-4; 1x10-3 and 3x10-3 min-1 at temperatures of 25?C, 35?C, 65?C and 90?C, respectively. The temperature dependence of the rate constant follows Arrhenius equation, and the value of activation energy of the reaction degradation is 48.2 kJ mol-1 . The effect of storage time at a temperature of 90 ?C on AA content in fresh juice of green peppers was investigated. It was shown that AA oxidation reaction in the juice is also the first order reaction, while the lower rate constant in relation to the pure AA (5x10-3 min-1) indicates the influence of other substances present in peppers. |
| Databáze: | OpenAIRE |
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