Six Lithuanian selection lines (137, 998/1000, 194/463, 21/1154, 1428, 1429) of edible tomato (Lycopersicon esculentum Mill.) were investigated in 2006–2007.

Fruit quality and physiological parameters were evaluated: the content of lycopene and β-carotene and colour indexes (L*, a*, b* and hue angle h⁰) at four different stages of fruit ripening (stage I – green, stage II – beginning of ripening, III – not fully ripened, IV – fully ripened), the average fruit number on plant and the average fruit weight.

The colour index a* showed the most obvious change, there was a sharp increase between stage I and other ripening levels with a* changing from negative (green color) to positive (red color) values. This could be related with the start of lycopene and β-carotene synthesis. When these carotenoids started to be synthesized, the L* value went down, indicating the darkening of tomato red colour, but in the selection line 1428 fruit colour from stage III to stage IV became lighter. The colour index b* values reached their peak at stage II when tomatoes started to get the red colour. In all the fruit ripening process, the hue angle had a tendency to decline, particularly the h0 value decreased between ripening stages I and II.

Keywords: colour index, lycopene, Lycopersicon esculentum, ripening stage