Mineral analysis (Fe, Zn, Ca, Na, K) of fresh Iberian pork loin by near infrared reflectance spectrometry -: Determination of Fe, Na and K with a remote fibre-optic reflectance probe

Near infrared spectrometry (NIRS) was used for the determination of the mineral concentrations of the elements iron, calcium, zinc, sodium and potassium in fresh samples of ground Iberian pork loin and for the determination of Fe, Na and K using a remote fibre-optic reflectance probe by direct application of the probe on intact loin. The regression method employed was the modified partial least squares (MPLS). The calibration results using 42 samples of ground pork loin had a corrected standard error of prediction (SEPC) and a correlation coefficient (RSQ) for Fe of 0.085 and 0.842; for Zn, 0.0097 and 0.695; for Ca, 0.101 and 0.761; for Na, 0.710 and 0.639 and for K, 4.414 and 0.781, respectively. The calibration results using NIR interactance with direct application to the same loin samples of a remote fibre-optic reflectance probe allowed the determination of the concentrations of Fe, Na and K, with SEPC and RSQ values of 0.084 and 0.898 for Fe; 0.698 and 0.757 for Na, and 6.760 and 0.775 for K. The robustness of the method was confirmed by applying it to eight samples of loin (ground and intact) for external validation. (C) 2002 Elsevier Science B.V. All rights reserved.