The transfer of fatty acid calibration equations using four sets of unsealed liquid standardisation samples

A database of 352 near infrared (NIR) spectral data from Iberian pig liquid fat was used for the prediction of palmitic, stearic, oleic and linoleic f atty acids content. The results showed the excellent accuracy of NIR equati ons with coefficients of determination (r(2)) reaching values close to 1 an d standard error of cross-validation (SECV) values similar to the standard error in the reference method (SEL). The possibility of transferring the ca librations developed in one instrument to another NIR instrument, following the Shenk and Westerhaus standardisation algorithm, was examined. Two mono chromator instruments were optically matched using four different standardi sation sets of unsealed samples (Set A: one sample of Iberian pig liquid fa t with a similar fatty acids composition to the average of the calibration set; Set B: 20 samples of Iberian pig liquid fat covering the range in opti cal density and fatty acid composition of the calibration set; Set C: oleic acid; Set D: linoleic acid. The standardisation completed with Set A and S et B produced spectra on the satellite instrument which resembled spectra s canned on the master instrument. The standard error of the differences (SED ) between the values predicted by the master and the satellite after standa rdisation were similar to, or even lower than, the standard error of predic tion (SEP) values for the same samples scanned on the master instrument.