title: Long-term stability of a Raman instrument determining iodine value in pork adipose tissue.
abstract: The stability of a calibration model from a non-destructive Raman instrument during a period of three years was studied. A calibration model created on a dataset measuring pork adipose tissue in 2005 determining iodine value (IV), was transferred to a dataset measuring pork adipose tissue three years later in 2008. During these three years the fibre optic cable had been changed and the output of the laser was reduced to 60% compared with the power in 2005. The samples were also taken from different parts of the carcass. Aligning the peak positions and pre-processing with multiplicative scatter correction together with a selection of wavelengths/wavenumbers gave, for IV, a correlation coefficient of 0.95 for measured versus predicted IV of the 2008 samples. The accuracy expressed as root mean square error of prediction was 2.04 g iodine added to 100g of melted fat with 6 partial least squares factors for the 2008 samples. This study shows that it is possible, with minor modifications, to transfer the model from spectra measured three years later on the same instrument. It is concluded that a quantitative use of Raman instruments are robust over time.
authors.affiliation: Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, PO Box 5036, N-1432 As, Norway. elisabeth.fjaervoll.olsen@umb.no
authors.forename: Elisabeth Fjaervoll
authors.initials: EF
authors.lastname: Olsen
authors.forename: Camilla
authors.initials: C
authors.lastname: Baustad
authors.forename: Bjørg
authors.initials: B
authors.lastname: Egelandsdal
authors.forename: Elling-Olav
authors.initials: EO
authors.lastname: Rukke
authors.forename: Tomas
authors.initials: T
authors.lastname: Isaksson
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000818:Animals; D002138:Calibration; D004041:Dietary Fats; D007455:Iodine / Q000032:analysis*; D008460:Meat / Q000032:analysis*; D008956:Models, Chemical; D013059:Spectrum Analysis, Raman / Q000295:instrumentation*; D013552:Swine
chemical_list: D004041:Dietary Fats; D007455:Iodine