Several variable selection algorithms were applied in order to sort informative wavelengths for building a
partial least-squares (PLS) model relating visible/near infrared spectra to Brix degrees in samples of sugar
cane juice. Two types of selection methods were explored. A first group was based on the PLS regression
coefficients, such as the selection of coefficients significantly larger than their uncertainties, the estimation of
the variable importance in projection (VIP), and uninformative variable elimination (UVE). The second group
involves minimum error searches conducted through interval PLS (i-PLS), variable-size moving-window
(VS-MW), genetic algorithms (GA) and particle swarm optimization (PSO). The best results were obtained
using the latter two methodologies, both based on applications of natural computation. The results furnished
by inspection of the spectrum of regression coefficients may be dangerous, in general, for selecting
informative variables. This important fact has been confirmed by analysis of a set of simulated data
mimicking the experimental sugar cane juice spectra.