Degradation kinetics of anthocyanins in acerola pulp: comparison between ohmic and conventional heat treatment.

Autor: Mercali GD; Chemical Engineering Department, Federal University of Rio Grande do Sul (UFRGS), Rua Engenheiro Luiz Englert s/n, Porto Alegre/RS 90040-040, Brazil. gmercali@enq.ufrgs.br, Jaeschke DP, Tessaro IC, Marczak LD
Jazyk: angličtina
Zdroj: Food chemistry [Food Chem] 2013 Jan 15; Vol. 136 (2), pp. 853-7. Date of Electronic Publication: 2012 Aug 30.
DOI: 10.1016/j.foodchem.2012.08.024
Abstrakt: Degradation kinetics of monomeric anthocyanins in acerola pulp during thermal treatment by ohmic and conventional heating was evaluated at different temperatures (75-90°C). Anthocyanin degradation fitted a first-order reaction model and the rate constants ranged from 5.9 to 19.7 × 10(-3)min(-1). There were no significant differences between the rate constants of the ohmic and the conventional heating processes at all evaluated temperatures. D-Values ranged from 116.7 to 374.5 for ohmic heating and from 134.9 to 390.4 for conventional heating. Values of the free energy of inactivation were within the range of 100.19 and 101.35 kJ mol(-1). The enthalpy of activation presented values between 71.79 and 71.94 kJ mol(-1) and the entropy of activation ranged from -80.15 to -82.63 J mol(-1)K(-1). Both heating technologies showed activation energy of 74.8 kJ mol(-1) and close values for all thermodynamic parameters, indicating similar mechanisms of degradation.
(Copyright © 2012 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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