Rapid Quantification of Carotenoids and Fat in Atlantic Salmon (Salmo Salar L.) by Raman Spectroscopy and Chemometrics

Abstract

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 POLYSNV, 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.

Raman spectroscopic study of electron-beam irradiated cold-smoked salmon

“…Raman spectroscopy has been shown to be a useful tool to study structural changes in solid food systems such as fish and meat (Brøndum, Byrne, Bak, Bertelsen, & Engelsen, 2000;Herrero, 2008a;Herrero, Cambero, Ordóñez, de la Hoz, & Carmona, 2008;Pedersen, Morel, Andersen, & Engelsen, 2003) and to determine structural changes that occur during processing and storage of fish and seafood products such as surimi (Bouraoui, Nakai, & Li-Chan, 1997;Herrero, Carmona, & Careche, 2004;Herrero, Carmona, García, Solas, & Careche, 2005;MoosaviNasah, All, Ismail, & Ngadi, 2005). In addition, some authors have studied carotenoids and fat by Raman spectroscopy in salmon muscle (Afseth, Wold, & Segtnan, 2006;Henmi, Hata, & Takeuchi, 1990;Wold, Marquardt, Dable, Robb, & Hatlen, 2004). Characterization and discrimination of irradiated starch using Raman spectroscopy has been also performed (Kizil & Irudayaraj, 2006;Kizil, Irudayaraj, & Seetharaman, 2002).…”

Possibility for Improving Carcass Composition and Meat Quality Traits by Selective Breeding

“…Further, VIS showed to be efficient in estimation of pigments in the fillet. Wold et al [8] showed that Raman spectroscopy was a suitable method for none destructive estimation of pigments (r = 0.95) and fat % (r = 0.97) in the ground salmon meat.…”

New Strategies for Identifying Natural Products of Ecological Significance from Corals

“…Studies involving marine organisms are emerging, and Raman analysis has been applied to animals, algae, and dinoflagellates, which have identified carotenoids, sterols, nonsubstituted conjugated polyenals, chromophores of green fluorescent proteins (GFPs), chlorophylls, melanins, and mycosporine-like amino acids (MAAs). Carotenoids have been identified from corals [140][141][142], mollusks [143,144], lobster carapace [145,146], fish [147], brown algae [148] and dinoflagellates [149]. Polyenals are a recently described class of polyenes identified from shells of mollusks [143,144] and octocorals [140][141][142][150][151][152][153].…”