title: Vibrational spectroscopic analysis of hake (Merluccius merluccius L.) lipids during frozen storage.
abstract: Vibrational spectroscopy (mid FTIR and FT-Raman) was used to monitor lipids extracted from hake fillets during frozen storage. Kramer shear resistance was used as a marker of texture changes and lipid damage was also investigated by following the development of conjugated dienes and free fatty acids by spectrophotometric methods. Results show that the intensity of the free fatty acid carboxylic ν(CO) band measured by ATR-FTIR spectroscopy can be used for monitoring the development of lipid hydrolysis in hake lipids. Changes in the Raman ν(CC) stretching region (1658cm(-1) band), partially attributed to conjugated dienes development, were the only observed spectroscopic alterations related to lipid oxidation of hake lipids during frozen storage at -10°C. The high correlation of free fatty acids with instrumental texture and the disappearance of the νas(PO2(-)) band are consistent with membrane lipid hydrolysis being one of the factors directly related with toughening of lean fish flesh.
authors.affiliation: Instituto de Estructura de la Materia (IEM-CSIC), Serrano 121, 28006 Madrid, Spain. Electronic address: isblsa@hotmail.com.
authors.forename: Isabel
authors.initials: I
authors.lastname: Sánchez-Alonso
authors.affiliation: Instituto de Estructura de la Materia (IEM-CSIC), Serrano 121, 28006 Madrid, Spain.
authors.forename: Pedro
authors.initials: P
authors.lastname: Carmona
authors.affiliation: Instituto de Ciencia y Tecnología de Alimentos y Nutrición (ICTAN-CSIC), José Antonio Nováis 10, 28040 Madrid, Spain.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Careche
mesh_terms: D000818:Animals; D005399:Fishes; D061353:Food Storage; D005628:Frozen Foods / Q000032:analysis*; D048388:Gadiformes / Q000378:metabolism*; D050356:Lipid Metabolism; D008066:Lipolysis; D010084:Oxidation-Reduction; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods*; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014732:Vibration
keywords: Fish; Fish muscle; Fourier transform; Free fatty acids; Frozen storage; Infrared spectroscopy; Lipid oxidation; Lipolysis; Raman spectroscopy