Published 2004

Read in Norwegian

Publication details

Journal : Applied Spectroscopy , vol. 58 , p. 395–403 , 2004

International Standard Numbers :
Printed : 0003-7028
Electronic : 1943-3530

Publication type : Academic article

Contributors : Wold, Jens Petter; Marquardt, Brian; Dable, Brian K.; Robb, Dave; Hatlen, Bjarne

Issue : 4

If you have questions about the publication, you may contact Nofima’s Chief Librarian.

Kjetil Aune
Chief Librarian


Raman spectroscopy (785 nm excitation) was used to determine the overall carotenoid (astaxanthin and cantaxanthin) and fat content in 49 samples of ground muscle tissue from farmed Atlantic salmon (Salmo salar L.). Chemically determined contents ranged from 1.0 to 6.8 mg/kg carotenoids and 36 to 205 g/kg fat. In addition to the raw Raman spectra, three types of spectral preprocessing were evaluated: the first derivative, subtraction of the fitted fourth-order polynomial (POLY), and the intensity normalized versions of POLY (POLY-SNV). Further, variable selection based on significance testing by use of jack-knifing was performed on each spectral data set. Partial least-squares regression resulted in a root mean square error of prediction of 0.33 mg/kg (R = 0.97) for carotenoids for the variable selected versions of all the preprocessed spectral data sets. The fat content was best estimated by the variable selected POLY-SNV, resulting in a root mean square error of prediction of 15.5 g/ kg (R = 0.95). Both preprocessing and variable selection improved the regression models significantly. The results demonstrate that Raman spectroscopy is a suitable method for simultaneous, rapid, and nondestructive quantification of both pigments and fat in ground salmon muscle tissue.