title: Evaluation of non-thermal effects of electricity on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating.
abstract: The effect of electric field on ascorbic acid and carotenoid degradation in acerola pulp during ohmic heating was evaluated. Ascorbic acid kinetic degradation was evaluated at 80, 85, 90 and 95°C during 60 min of thermal treatment by ohmic and conventional heating. Carotenoid degradation was evaluated at 90 and 95°C after 50 min of treatment. The different temperatures evaluated showed the same effect on degradation rates. To investigate the influence of oxygen concentration on the degradation process, ohmic heating was also carried out under rich and poor oxygen modified atmospheres at 90°C. Ascorbic acid and carotenoid degradation was higher under a rich oxygen atmosphere, indicating that oxygen is the limiting reagent of the degradation reaction. Ascorbic acid and carotenoid degradation was similar for both heating technologies, demonstrating that the presence of the oscillating electric field did not influence the mechanisms and rates of reactions associated with the degradation process.
authors.affiliation: Chemical Engineering Department, Federal University of Rio Grande do Sul, Engenheiro Luiz Englert Street, Porto Alegre, RS, 90040-040, Brazil. Electronic address: deborapj@enq.ufrgs.br.
authors.forename: Débora Pez
authors.initials: DP
authors.lastname: Jaeschke
authors.affiliation: Chemical Engineering Department, Federal University of Rio Grande do Sul, Engenheiro Luiz Englert Street, Porto Alegre, RS, 90040-040, Brazil.
authors.forename: Ligia Damasceno Ferreira
authors.initials: LD
authors.lastname: Marczak
authors.affiliation: Department of Food Science and Technology, Federal University of Rio Grande do Sul, Bento Gonçalves Avenue, 9500, Porto Alegre, RS, 91501-970, Brazil.
authors.forename: Giovana Domeneghini
authors.initials: GD
authors.lastname: Mercali
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry*; D002338:Carotenoids / Q000737:chemistry*; D004560:Electricity; D006358:Hot Temperature; D029581:Malpighiaceae / Q000737:chemistry*
chemical_list: D002338:Carotenoids; D001205:Ascorbic Acid
keywords: Acerola pulp; Ascorbic acid; Carotenoid; Ohmic heating