Colour Changes in Ripening Fruits and Vegetables
Produced by Science & Plants for Schools (SAPS), these investigations look at how pigments change during the fruit ripening process.
The green colour of the unripe fruit is due largely to the presence of chlorophylls, and the development of different colours during ripening is due to the disappearance of these pigments and the synthesis of carotenoids. Anthocyanins also make a contribution to colours in some ripe fruits and vegetables.
Students set up investigations to follow the changes in the concentrations of these pigments during ripening. Using a colorimeter, students are able measure the relative amount of red versus green pigments (anthocyanins versus chlorophyll) in plant tissues.