Changes in composition of the lipid matrix produce a differential incorporation of carotenoids in micelles. Interaction effect of cholesterol and oil

Abstract

Abstract Efficiency of the micellar incorporation of carotenoids was determined through the application of an in vitro digestion procedure, and in function of the composition of the lipophilic environment, where digestion was carried out. Analysed factors affecting micellization level were presence of oil in the digestion mixture, class of pigment, and cholesterol. The addition of oil to the digestion mixture caused changes of different extent in function of the class of pigment, and significant interactions between the factors presence of oil and class of pigment were detected. Accessibility of lycopene was affected negatively by an increase of the amount of vegetable oil, while lutein ester increased its presence in micelles. Although cholesterol was not a significant factor affecting the micellization efficiency, when cholesterol and oil were added to the digestion process, the amount of micellarized pigment was significantly affected, positively or negatively depending on lipophilic characteristics of the pigment. Therefore, an interaction between the factors cholesterol and presence of oil with different effects on the micellization of pigments was analysed. The physical–chemical differences of carotenoids, that are consequence of their structural features, generated diverse requirements of the lipophilic environment to facilitate their emulsion and subsequent incorporation into micelles. Industrial relevance Carotenoid pigments are widely used by the food industry as colorants, although nutritional and functional properties make them to be applied for other purposes, as in the enhancement of functional foods. The physico-chemical characteristics of carotenoids make them to be low bioavailable, so that a correct formulation of the food matrix is required in order to achieve an appropriate bioavailability. The development of in vitro digestion methods, which allow the measurement of the potential bioavailability of carotenoids, could be considered as a useful tool to screen those factors and components that modify the bioavailability of these compounds in a given matrix composition so selection of the formulation conditions that gives the higher availability may be performed. The aim of this work was the development and application of an in vitro method to measure the potential bioavailability of carotenoids considering several factors that modulate it.