Determination of Diffusion Coefficients and Antioxidant Activities of Ascorbic Acid in Guava Juice using Cyclic Voltammetry

Ascorbic acid is the most abundant antioxidant present in guava (Psidiumguajava L.). There had only been few studies concerning the determination of diffusion coefficient and antioxidant activity of ascorbic acid in guava juice using cyclic voltammetry specifically at varying temperatures. Thus, thi...

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Bibliographic Details
Published in:IOP conference series. Materials Science and Engineering 2020-04, Vol.778 (1), p.12037
Main Authors: Ang, K. B. A., Lee, C. M., Yu, H. M. O., Uy, M., Soriano, A. N., Dugos, N. P.
Format: Article
Language:English
Subjects:
Acids
Antioxidants
Ascorbic acid
Diffusion coefficient
Diffusion effects
Electrodes
Glassy carbon
Guava
Juices
Silver chloride
Temperature effects
Vitamin C
Voltammetry
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Summary:Ascorbic acid is the most abundant antioxidant present in guava (Psidiumguajava L.). There had only been few studies concerning the determination of diffusion coefficient and antioxidant activity of ascorbic acid in guava juice using cyclic voltammetry specifically at varying temperatures. Thus, this study on the effect of temperature on diffusion coefficient and antioxidant activity on ascorbic acid found in guava was done using cyclic voltammetry. The temperatures tested were at 15°C, 25°C, 36°C, and 45°C. Electrodes used in the experiment were glassy carbon as the working electrode, platinum wire as the counter electrode, and Ag/AgCl electrode as the reference electrode. The results showed that the peak currents of ascorbic acid in guava juice at 15°C, 25°C, 36°C, and 45°C were -0.5720, -0.5380, -0.5000, and -0.4760 μA, respectively. The diffusion coefficients of the ascorbic acid were obtained using the Randles-Sevcik equation at all given temperatures and the values were 2.1489 x10−5, 2.1711 x10−5, 2.2070 x10−5, and 2.2250 x10−5 cm2/s, respectively. The antioxidant activities, in terms of concentration, at the said temperatures were found to be 0.3374, 0.3212, 0.3015, and 0.2899 mM, respectively. It is concluded that at higher temperature, ascorbic acid in guava juice has a higher diffusion coefficient but lower antioxidant activity. The present results can be used by other researchers doing similar work on fate and transport of the studied system.
ISSN:1757-8981
1757-899X
DOI:10.1088/1757-899X/778/1/012037