Role of carotenoid type on the effect of thermal processing on bioaccessibility.

Cell walls and chromoplast substructures constitute natural structural barriers governing carotenoid bioaccessibility. In order to enhance carotenoid bioaccessibility, thermal processes were applied to fractions surrounded by different levels of structural barriers. The matrices studied were orange carrots, red carrots, red tomatoes and atomic red carrots. In the case of carrots, no effect of thermal treatments on carotenoid bioaccessibility at the chromoplast level was obtained. However, in the case of tomatoes, lycopene bioaccessibility decreased upon thermal processing of chromoplasts. At the cell cluster level, low intensities of thermal processing resulted in a decrease of β-carotene and lycopene bioaccessibility. Nonetheless, at high intensities of thermal processing, only β-carotene bioaccessibility was increased. This observation was confirmed by the results obtained in the matrix rich in both types of carotenoids (atomic red carrots). It was therefore suggested, that the type of carotenoid constitutes an important factor determining the effect of thermal processing on their bioaccessibility.