Texture evaluation in cheeses by NIRS technology employing a fibre-optic probe

The use of NIRS (near infra-red spectroscopy) technology together with a remote-reflectance fibre-optic probe was studied for the analysis of ewe's cheese texture. The cheeses were elaborated with milk from three breeds of sheep (Castellana, Churra and Assaf) with different somatic cell counts (SCC) (lower than 500,000 cells m L-1; between 1,000,000 and 1,500,000 cells m L-1, and more than 2,500,000 cells m L-1) and ripened for 12 months, thus 96 samples were obtained. At each ripening time NIRS spectra were recorded and instrumental texture were determined as Warner-Bratzler shear force using a TX-T2iplus. The regression method employed was modified partial least squares (MPLS). The calibration, with the multiple correlation coefficients (RSQ), 0.961 and standard error of prediction (SEP(C)) of 2.1 N, allows determining texture in the range 0.0-49.0 N. The ratio performance deviation (RPD) value obtained, 5.4, indicate that the NIRS equation obtained was applicable to unknown samples. (C) 2008 Elsevier Ltd. All rights reserved.