Nutritive evaluation of olive tree leaves by near-infrared spectroscopy: effect of soil contamination and correction with spectral pretreatments.
Olive leaves obtained as a byproduct in the Mediterranean region could play an important role in the nutrition of extensive ruminant systems. However, the reported variation in their nutritive value, among other reasons due to discrepancies in mineral content, is considered an important obstacle for their common use. Near-infrared spectroscopy (NIRS) could fulfill the requirements of these productive systems, providing analytical information in a rapid and economic way. In this work, the effect of soil contamination on NIR spectra has been studied, as well as its correction with some of the most commonly used spectral pretreatments (derivatives, multiplicative scatter correction, auto scaling, detrending, and a combination of the last two transforms). Effects were evaluated by visual inspection of the transformed spectra and comparison of the calibration statistics obtained to estimate acid insoluble ash and total ash contents and in vitro pepsin cellulase digestibility of organic and dry matter. The incidence of spectral curvature effects caused by soil contamination that can be conveniently corrected with pretreatments such as derivatives was confirmed.
Fernández-Cabanás
V M
VM
Escuela Universitaria de Ingeniería Técnica Agrícola, University of Seville, Ctra, Utrera Km. 1. 41013 Sevilla, Spain. victorf@us.es
Garrido-Varo
A
A
Delgado-Pertiñez
M
M
Gómez-Cabrera
A
A
D000821:Animal Feed / Q000032:analysis*; D016477:Artifacts; D005504:Food Analysis / Q000379:methods*; D013058:Mass Spectrometry / Q000379:methods*; D031658:Olea / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry*; D012680:Sensitivity and Specificity; D012989:Soil Pollutants / Q000032:analysis / Q000737:chemistry*
D012989:Soil Pollutants