title: Visible spectroscopy on carcass fat combined with chemometrics to distinguish pasture-fed, concentrate-fed and concentrate-finished pasture-fed lambs.
abstract: We used visible spectroscopy of fat to discriminate lambs that were pasture-fed (n=76), concentrate-fed (n=79) or concentrate-finished after pasture-feeding (n=69). The reflectance spectrum of perirenal and subcutaneous caudal fat was measured at slaughter and 24h post mortem. In Method 1 (W450-510), the optical data were used at wavelengths in the range of 450-510nm to calculate an index quantifying light absorption by carotenoids. In Method 2 (W400-700), the full set of data at wavelengths in the range of 400-700nm was used to differentiate carcasses using PLS-DA as a classification method. W400-700 proved more reliable than W450-510 (P<0.0001). The proportion of correctly classified lambs using W400-700 was 95.6% and 95.9% for measurements made on perirenal fat at slaughter and 24h post mortem. The intensity of light absorption by carotenoids decreased exponentially with live weight gain during the finishing period.
authors.affiliation: Institut National de la Recherche Agronomique, INRA, UR1213 Herbivores, Site de Theix, F-63122 Saint-Genès-Champanelle, France.
authors.forename: Y
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Institut National de la Recherche Agronomique, INRA, UR1213 Herbivores, Site de Theix, F-63122 Saint-Genès-Champanelle, France.
authors.forename: D
authors.initials: D
authors.lastname: Andueza
authors.affiliation: Institut National de la Recherche Agronomique, INRA, UR1213 Herbivores, Site de Theix, F-63122 Saint-Genès-Champanelle, France; Universidade Federal do Rio Grande do Sul, UFRGS, Av. Bento Gonçalves 7712, CEP 91501-970 Porto Alegre, RS, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: de Oliveira
authors.affiliation: Institut National de la Recherche Agronomique, INRA, UR1213 Herbivores, Site de Theix, F-63122 Saint-Genès-Champanelle, France; Universidade Estadual de Maringá, UEM, Av. Colombo 5.790, CEP 87020-900 Maringá-Pr, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Zawadzki
authors.affiliation: Institut National de la Recherche Agronomique, INRA, UR1213 Herbivores, Site de Theix, F-63122 Saint-Genès-Champanelle, France. Electronic address: sophie.prache@clermont.inra.fr.
authors.forename: S
authors.initials: S
authors.lastname: Prache
mesh_terms: D000273:Adipose Tissue / Q000737:chemistry*; D000821:Animal Feed; D000822:Animal Husbandry / Q000379:methods*; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001823:Body Composition; D002338:Carotenoids / Q000737:chemistry; D008027:Light; D008460:Meat / Q000032:analysis*; D006109:Poaceae; D015203:Reproducibility of Results; D012756:Sheep; D013057:Spectrum Analysis / Q000379:methods*; D015430:Weight Gain
chemical_list: D002338:Carotenoids
keywords: Authentication; Chemometrics; Pasture-feeding; Sheep; Spectroscopy; Stall-finishing