"A fungal–infected kernel would
also scatter more light than a sound, vitreous kernel because
the invasion of the fungus causes the kernel endosperm to
become powdery (Hesseltine and Shotwell, 1973; Lillehoj et
al., 1976). This scattering would cause more NIR (>750 nm)
radiation to be absorbed in transmission mode, and less NIR
radiation to be absorbed in reflectance mode. Powdery
substances with refractive indices different than air, such as
in the air–endosperm interface of infected kernels, cause
more light to be reflected (Birth and Hecht, 1987), as opposed
to the more crystal–like property of normal kernels."
(Page 1250 in
Pearson, T.C., Wicklow, D.T., Maghirang, E.B., Xie, F., Dowell, F.E. (2001) DETECTING FLATOXIN IN SINGLE CORN KERNELS BY TRANSMITTANCE AND REFLECTANCE SPECTROSCOPY, Transactions of the ASAE, Vol 44(5), 1247 - 1254.)
