Testing of kinetic models: usefulness of the multiresponse approach as applied to chlorophyll degradation in foods

Cascades of reactions, in which several reactants and products take part, f requently occur in foods. This work shows that kinetic modelling of such re actions having parameters in common is much more powerful when using a mult iresponse rather than a uniresponse approach (i.e. analysing more than one reactant/product at the same time rather than only one reactant or product) . With multiresponse modelling proposed kinetic models can be tested rigoro usly for their validity (not really possible with the uniresponse approach) , and the precision of the parameters estimated is much increased. Multires ponse modelling requires (in most cases) not minimization of least squares but that of the determinant of the so-called dispersion matrix, consisting of sums of cross-products of the responses measured. Kinetic models describ ing breakdown of chlorophyll in foods were taken from literature and multir esponse modelling was shown to lead to a better insight in, and indeed impr ovement of such kinetic models. (C) 1999 Canadian Institute of Food Science and Technology. Published by Elsevier Science Ltd. All rights reserved.