An electronic tongue as a tool for assessing the impact of carotenoids' fortification on cv. Arbequina olive oils

Abstract

The consumption of carotenoids has several health benefits. It is known that the fortification of olive oils with carotenoids, namely -carotene or lutein, enhanced the oils physicochemical properties, being a possible strategy to increase carotenoids intake. This study showed that a lab-made potentiometric electronic tongue, comprising lipid sensor membranes, could discriminate non-fortified olive oils from those fortified with different levels -carotene or lutein (repeated K-fold cross-validation sensitivities: 87±8%), confirming the impact of the fortification on the oils phenolic contents and sensory sensations. Moreover, the device could, semi-quantitatively, discriminate oils fortified with different amounts (0, 0.05, 0.10, and 0.15 mg/mL) of each carotenoid (repeated K-fold cross-validation sensitivities: 94±9% and 97±7%, for -carotene and lutein, respectively). This could be related to the capability of detecting increasing levels of the carotenoids and to the ability to assess the changes induced by the addition of carotenoids on the total phenols contents and on the intensities of the basic taste sensations. Indeed, satisfactory first- or second-order correlations could be established between the centroids of the first discriminant functions of the linear discriminant models and the carotenoid fortification levels, the total phenols contents, as well as with the sweetness, bitterness, and pungency intensities of the fortified oils (0.865R20.998). The successful qualitative and (semi-)quantitative performance of the electronic tongue may foresee its future application as a practical and cost-effective tool for assessing the impact of the fortification of olive oils with carotenoids at the carotenoids, phenols, and basic taste levels.