3. Results and discussion
3.1. Visual spectra
The original reflectance spectra of a few mangoes in
the wavelength range between 400 and 700 nm are
shown inFig. 1. Visual inspection of the spectra did not
show any obvious special features, which could be used
in quantitative measurement, except that the relative
reflectance increases with wavelength between 500 and
550 nm, and above 670 nm. The peak and depression in
the spectra around 550 and 670 nm showed the strong
and weak reflectance characteristics of mango, respectively, within the range of the study.