Spectroscopic methods have been proposed to predict sugarcane quality in the field. There are different sample forms could
be used to predict sugar content using spectroscopic methods; raw juice (RJ), clear juice (CJ), fibrated samples (FS), stalk
cross sectional surface (SCS) and stalk skin (SS). Thus, this study was conducted to identify the optimum sample form for
predicting quality using a low-cost and portable spectrometer. A total of 100 samples from each sample form were scanned
using a visible-shortwave near infrared (Vis/SWNIR) spectrometer. The experiment was conducted under the same
experimental setup and all data were treated using the same statistical methods. All spectral data were calibrated against
brix value. The coefficient of determination (R2) for SCS, FS, CJ, SS and RJ were 0.88, 0.86, 0.84, 0.84, 0.81 and 0.80,
respectively. The study found that a Vis/SWNIR spectrometer could be used to predict sugar content from all sample forms.
The stalk samples scanned on cross sectional surface was found to be the optimum sample form for quality prediction using
a Vis/SWNIR spectrometer.