Colour parameters as indicators of lycopene and antioxidant activity traits of cherry tomatoes (Solanum lycopersicum L.)

Abstract

There is limited information available on lycopene content and antioxidant activity of new special coloured cherry tomatoes. We also lack data regarding the effects of on the correlation between the commonly applied colour formulas of surface, puree and lycopene content as well as the effect of extraction solvent on the results of antioxidant activity assays. In this study 11 cherry tomatoes including 5 colours (red, bright red, red-green, yellow, orange) from commercial trade were assessed. Surface and puree colours were determined by a hand-top colorimeter using Lab colour space. Lycopene content was measured as well as the FRAP-, DPPH-, CUPRAC-, ABTS- and TPC-assay following extraction by either water, ethanol or methanol. Our results indicate that the most commonly applied formulas are not disturbed by the special coloured varieties. The colour of puree correlated better with the lycopene content than the values measured on the surface. The method-extraction combination ranking showed that the CUPRAC-EtOH and supernatant ones were the best to distinguish cherry tomato samples. Correlation of chromaticity values was strong with the FRAP-assay and with the DPPH-method. We can conclude that colour parameters as indicators of lycopene content are not disturbed by the special coloured varieties and also have some correlation with antioxidant-capacity assays.