The chlorophylls and carotenoids content
of the fruit skin and associated tissue provides
the skin ground color of the fruit.
During fruit maturity, a shift in the balance
of chlorophyll breakdown and synthesis
occurs [3], which gradually results in a
decrease in the chlorophyll content in
mature fruit [4, 5]. This decrease in chlorophyll
content may therefore be considered
as an indicator of the banana fruit maturity
[6]. Color cards, which match the banana
fruit skin color at different maturity stages,
are commonly used to obtain information
on fruit maturity and related market quality.
While this method is inexpensive and nondestructive,
visual methods are influenced
by subjective perception. However, chemical
analyses performed in research are not
applicable for rapid monitoring of single
fruit. Therefore instrumental monitoring of
fruit skin color could represent a possible
tool for estimating maturity.
In recent years, it has been assumed
that the fruit skin color, measured as the
a*-value in a L*a*b* color model, might correlate
with the chlorophyll content and
could improve the fruit maturity determination
[7]. This apparent suggestion has not
been proven since color spaces only insufficiently
describe pigment changes during
fruit maturation. In remote sensing applica