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Kinetics of the decolouring of carotenoid pigments

1995; Wiley; Volume: 67; Issue: 2 Linguagem: Inglês

10.1002/jsfa.2740670203

1097-0010

María Isabel Mínguez‐Mosquera, Manuel Jarén‐Galán,

Crystallization and Solubility Studies

Abstract The decolouring reaction of carotenoids was studied using β‐carotene, di‐esterified capsanthin and capsanthin. The study was designed to determine what effects the increase in temperature, the nature of the reaction medium and the presence of light have on the kinetics of the reaction. The reactions that take place in an anhydrous medium follow a zero‐order kinetics, while those that take place in an aqueous medium follow a first‐order kinetics. Light and temperature accelerate the degradation reaction without changing the formal aspects of the reactions. The values for the thermodynamic parameters (activation energy and enthalpy of activation) of each reaction were different according to the conditions used, but this variation was due to a compensation effect. However, the existence of this effect confirms that the decolouring reaction is the first step of the carot‐enoid degradation, and this step is identical for all of the pigments irrespective of the reaction conditions, although the formal aspects and kinetics of this first step are strongly modulated by the nature of the pigment and the experimental conditions used.