S. Roy et al., DETERMINATION OF MOISTURE-CONTENT OF MUSHROOMS BY VIS NIR SPECTROSCOPY, Journal of the Science of Food and Agriculture, 63(3), 1993, pp. 355-360
Feasibility of the determination of the moisture content of intact ind
ividual mushrooms (Agaricus bisporus) by visible and near infrared ref
lectance spectroscopy (Vis-NIR) was studied. The convection drying met
hod was found to be suitable to obtain reference values for the calibr
ation equation. The standard error of the laboratory procedure ranged
from 0.16 to 0.42%. Modified partial least square regression was used
to develop the calibration equations. The importance of different segm
ents of wavelength, the effect of light scattering and the use of data
processing on the prediction of moisture content were evaluated. The
equation obtained using the wavelength segment 600-2200 nm with first
derivative and scatter correction had the best performance with a stan
dard error of cross-validation of 0.64%. This equation performed very
well when validated using a separate set of mushrooms of the same kind
as those in calibration set. This equation, however, did not perform
well when using mushrooms from a different treatment. Accuracy of pred
iction was re-established by adding typical spectra from the second gr
oup of mushrooms to the calibration set and performing recalibration.