Effect of multiplicative scatter correction on wavelength selection for near infrared calibration to determine fat content in raw milk

The effect of multiplicative scatter correction (MSC) on wavelength selection for near infrared (NIR) calibration to determine fat content in raw milk was investigated. Short-wave NIR spectra (700-1100 nm) of raw milk samples were measured. The calibration equations for fat content were performed by multiple linear regression (MLR) using original, second derivative and MSC-treated spectra. It was found that first wavelength selection from the fat absorption band for a calibration equation was generally effective in all cases of original, second derivative and MSC-treated spectra. However, correlation plots did not always work well because of the multiplicative scatter effect presented in the samples. Whereas, correlation plots were still useful in the case of MSC-treated spectra and normalised second derivative spectra, even when the original spectra exhibited a multiplicative scatter effect.