title: Extended multiplicative signal correction as a tool for separation and characterization of physical and chemical information in Fourier transform infrared microscopy images of cryo-sections of beef loin.
abstract: Extended multiplicative signal correction (EMSC) is used to separate and to characterize physical and chemical information in spectra from Fourier transform infrared (FT-IR) microscopy. This appears especially useful for applications in infrared spectroscopy where the scatter variance in spectra changes with the chemical variance in the sample set. In these cases the chemical information of specific bands that are assigned to functional groups is easier to interpret when the scatter information is removed from the spectra. We show that scatter (physical) information in FT-IR spectra of heat-treated beef loin is related to chemical changes due to heat treatment. This information is caused by textural changes induced by the heat treatment and expressed by physical effects as the optical path length. The chemical absorbance changes introduced in the FT-IR spectra due to heat treatment are shifts in the protein region of the infrared spectrum caused by changes in the secondary structure of the proteins. If the scatter and the chemical information is not separated properly, scatter information may erroneously be interpreted as chemical information.
authors.affiliation: Centre for Biospectroscopy and Data Modelling, Norwegian Food Research Institute, Matforsk, Osloveien 1, N-1430 As, Norway. kohler@matforsk.no
authors.forename: A
authors.initials: A
authors.lastname: Kohler
authors.forename: C
authors.initials: C
authors.lastname: Kirschner
authors.forename: A
authors.initials: A
authors.lastname: Oust
authors.forename: H
authors.initials: H
authors.lastname: Martens
mesh_terms: D000465:Algorithms; D000818:Animals; D002417:Cattle; D003296:Cooking / Q000379:methods; D005504:Food Analysis / Q000379:methods*; D006358:Hot Temperature; D066298:In Vitro Techniques; D008460:Meat / Q000032:analysis*; D008853:Microscopy / Q000379:methods*; D009124:Muscle Proteins / Q000032:analysis* / Q000737:chemistry* / Q000378:metabolism / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000737:chemistry* / Q000166:cytology / Q000378:metabolism; D011489:Protein Denaturation; D017433:Protein Structure, Secondary; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D014018:Tissue Distribution
chemical_list: D009124:Muscle Proteins