Characterizing Pigments in Peppers

A group of researchers have characterized carotenoid and chlorophyll in different sweet bell peppers (Capsicum annuum L.) using offline multidimensional supercritical fluid chromatography (SFC) combined with reversed-phase liquid chromatography (LC) for the first time (1).

Bell peppers come in a range of colours, from green to red. All peppers start off life green and then change colour, to red, orange, or yellow, as they ripen. These colour changes are a result of the presence of carotenoid pigments, which are produced in greater amounts as the pepper ripens. 

The team used a 100 × 3 mm, 1.8-μm C18 column with a supercritical mobile phase in the first dimension and a 250 × 4.6 mm, 3.0-μm C30 column in reversed-phase mode in the second dimension. This multidimensional approach enabled the team to determine 115 different compounds belonging to chlorophylls, free xanthophylls, free carotenes, xanthophyll monoesters, and xanthophyll diesters. This was a significant improvement compared to the conventional one-dimensional LC approach that was previously applied to sweet bell peppers. - K.M.

Reference

• L. Mondello et al., Journal of Separation Science39, 3281–3291 (2016).