LYCOPENE CONCENTRATION OF TOMATO FRUIT CAN BE ESTIMATED FROM CHROMATICITY VALUES

Chromaticity values (L*, a*, b*) of tomato (Lycopersicon esculentum Mill. 'Celebrity', 'Early Pick', and 'Mountain Delight') were measured using a Minolta CR-200b tristimulus colorimeter. Lycopene concentrations in acetone extracts of skin disks or pericarp plugs were measured spectrophotometrically at 503 nm. The L* or a* value was related to lycopene concentration in all the cultivars; however, the ratio of (a*/b*)2 provided the best R2 for all cultivars (0.75). These relationships allow the use of a portable colorimeter for rapid, nondestructive estimation of tomato fruit lycopene concentrations in laboratory or in situ studies.