Determina？？o de umidade em café cru usando espectroscopia NIR e regress？o multivariada

near infra-red reflectance (nir) spectroscopy was used to measure the moisture content in raw coffee. different models using partial least squares (pls) with data pre-processing were used. regression models were built with 157 spectra of the samples of raw coffee collected using a near infrared spectrometer with an accessory of diffuse reflectance, between 4500 and 10000 cm-1. the original nir spectra went through different transformations and mathematical pre treatments, such as the kubelka-munk transformation; multiplicative signal correction (msc); spline smoothing and movable average, and the data were scaled by variance. the regression model permitted the determination of the moisture content of the raw coffee samples with a standard error of calibration (sec) = 0.569 g.100 g -1; standard error of validation = 0.298 g.100 g -1; correlation coefficient (r) 0.712 and 0.818 for calibration and validation, respectively, and average relative error of 4.1% for validation samples.