4. Conclusions
Tests of the handheld hyperspectral imaging system demonstrate
that the system can acquire spectra at 5 nm intervals from
460 to 720 nm in about 11 s, and that fluorescence-based responses
to violet LED excitation can be detected under ambient
fluorescent lighting by utilizing wavelengths, such as 475, 520,
and 675 nm, where the intensity of ambient lighting is relatively
low. By automatically cycling through these three wavelengths,
the system can be used to detect wear on HDPE surfaces as well
as the presence of produce residues. These characteristics along
with sensitivity of the system, demonstrated by the ability to easily
detect small quantities of juice released when pieces of honeydew
or cantaloupe melon were repositioned on a HDPE cutting board,
suggest that the instrument will be a valuable tool for assessing
the efficacy of cleaning and sanitation procedures
the contrast at 475 nm was greater than the contrast at
675 nm. This difference in contrast suggests that scanning could
be done at a greater distance while using imaging at 475 nm to
bringing attention to possible small pieces of produce residue.
The camera head could then be brought closer to the suspected
anomaly to allow e
faintly visible with violet excitation when the ambient lights were
turned off. The pieces were cut on a different cutting board, transferredtransferred
to a paper cup, and then placed on the imaging cutting board
by lifting them out of the cup. Thus, the juices shown in images are
primarily the result of ‘‘damage’’ resulting from dragging the pieces
675 nm images is indicative of the sensitivity of the imaging device.