Abstract
Ascorbic acid degradation experiments were performed in buffer solution at pH 3.5 using a batch ohmic heater with uncoated stainless steel electrodes. The electrical conductivity of the buffer solution was adjusted using sodium chloride. The concentration of ascorbic acid was found using an HPLC technique. Kinetics of degradation can be described adequately by a first order model for both conventional and ohmic treatments, but unlike conventional heating, the temperature dependence of degradation for some ohmic treatments cannot be represented by the Arrhenius relation. During ohmic heating, power, temperature and NaCl content affect the degradation rate. A number of reactions, including electrode reactions, electrolysis of the solution, as well as reactions between electrode materials and electrolysis products may influence the reaction mechanism as well as kinetic parameters. At the highest power and salt content, citrate complexation and a significant loss of buffering capacity were noted, resulting in an increase in pH. The results underline the importance of inert electrode coatings, or the use of high frequency power for control of electrochemical reactions.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
C.H. Biss, S.A. Coombes and P.J. Skudder, in R.W. Field and J.A. Howell (Eds), ‘Process Engineering in the Food Industry’ (Elsevier, 1989), p. 17.
G.V. Barbosa-Cánovas, M. Gongora-Nieto, U. Pothakamury and B. Swanson, ‘Processing of Foods with Pulsed Electric Fields’ (Academic Press, 1999).
A.A.P. de Alwisand P.J. Fryer, Chem. Eng. Sci. 45 (1990) 1547.
S.K. Sastry, J. Food Proc. Engr. 15 (1992) 263.
C. Amatore, M. Berthou and S. Hebert. J. Electroanal. Chem. 457 (1998) 191.
T. Tzedakis, R. Basseguy and M. Comtat, J. Appl. Electrochem. 29 (1999) 821.
A.E. Bender, ‘Nutritional Changes in Food Processing, Developments in Foods Preservation’, Vol. 4 (Elsevier, 1987), p. 1.
J.F. Gregory III, in T. Richardson (Ed), ‘Chemical changes of vitamins during food processing’ (AVI, 1985).
M.H. Eison-Perchonok and T.W. Downes, J. Food Sci. 47 (1982) 765.
Y.C. Lee, J.R. Kirk, C.L. Bedford and D.R. Heldman, J. Food Sci. 42 (1977) 640.
D.B. Dennison and J.R. Kirk J. Food Sci. 43 (1978) 609.
I. Saguy, I.J. Kopelman and S.J. Mizrahi. J. Food Proc. Engr. 2 (1978) 213.
N.S. Kincal and C. Giray, Int. J. Food Sci. and Technol. 22 (1987) 249.
B.M. Laing, D.L. Schlueter and T.P. Labuza, J. Food Sci. 43 (1978) 1440.
S. Palaniappan, S.K. Sastry and E.R. Richter, Biotech. & Bioeng. 39 (1992) 225.
R. Howard, T. Peterson and P. Kastl, J. Chrom. 414 (1987) 434–439.
C. Zapsalis and R.A. Beck, ‘Food Chemistry and Nutritional Biochemistry’ (Wiley, New York, 1986).
S.R. Tannenbaum, V.R. Young and D. Lorient, in O. Fennema (Ed), ‘Food Chemistry’ (Marcel Dekker, 1976), p. 477.
T.P. Coultate, ‘Food: the Chemistry of its Components’ (Royal Society of Chemistry, 1996).
R.P. Wayne, in A.A. Frimer (Ed), ‘Singlet O2 Vol. I. Physical-Chemical Aspects’ (CRC, 1985), p. 82.
J.A. Dean (Ed), ‘Lange'sHandboo k of Chemistry’, (McGraw-Hill, 13th edn, 1985).
J. Ko'nya, J. Electrochem. Soc. 126 (1979) 54.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Assiry, A., Sastry, S. & Samaranayake, C. Degradation kinetics of ascorbic acid during ohmic heating with stainless steel electrodes. Journal of Applied Electrochemistry 33, 187–196 (2003). https://doi.org/10.1023/A:1024076721332
Issue Date:
DOI: https://doi.org/10.1023/A:1024076721332