A new SPE/GC-fid method for the determination of cholesterol oxidation products. Application to subcutaneous fat from Iberian dry-cured ham.
A new method for the isolation and analysis of cholesterol oxidation products (COPs) using solid phase extraction (SPE) and silica columns was developed using gas chromatography-flame ion detection (GC-FID). The method comprises of saponification and liquid-liquid extraction of the unsaponifiable fraction prior to the isolation and derivatization of the COPs to trimethylsilyl ethers. The COPs used in this study are cholestane-5α-6α-epoxide, cholestane-3β-5α-6β-triol, 25-hydroxycholesterol and 5-cholesten-3β-ol-7-one. In order to identify the COPs fraction a GC-ion-trap-mass spectrometry experiment were conducted using authentic standards to verify the presence of the COPs. The method was effective at rapidly separating the COPs (25 min run). Calibration curves were linear with the LODs and LOQs bellow 0.03 and 0.07 mgkg(-1) for all cases, respectively. This methodology gave a total recovery for every compound that was used in the study. Betulin was used as an internal standard to monitor the recovery. The method was validated with a standard mixture of COPs. The method has been applied to characterize the COP fraction of subcutaneous fat from Iberian dry-cured ham. Cholestane-5α-6α-epoxide, cholestane-3β-5α-6β-triol, 25-hydroxycholesterol and 5-cholesten-3β-ol-7-one have been identified for the first time in these samples.
Food Characterization and Quality Department, Instituto de la Grasa (C.S.I.C.), Avda. Padre García Tejero 4, 41012 Seville, Spain.
Mónica
M
Narváez-Rivas
Department of Food Science, Nutrition, and Health Promotion, Box 9805, Mississippi State University, MS 39762, United States.
Alessandra J
AJ
Pham
Department of Food Science, Nutrition, and Health Promotion, Box 9805, Mississippi State University, MS 39762, United States.
M Wes
MW
Schilling
Food Characterization and Quality Department, Instituto de la Grasa (C.S.I.C.), Avda. Padre García Tejero 4, 41012 Seville, Spain. Electronic address: mleon@cica.es.
Manuel
M
León-Camacho
D000818:Animals; D002784:Cholesterol / Q000032:analysis / Q000378:metabolism*; D002849:Chromatography, Gas / Q000379:methods; D005410:Flame Ionization / Q000379:methods; D008460:Meat / Q000032:analysis; D010084:Oxidation-Reduction; D052616:Solid Phase Extraction / Q000379:methods*; D050151:Subcutaneous Fat / Q000737:chemistry / Q000378:metabolism*; D013552:Swine
D002784:Cholesterol
Cholesterol oxidation products; GC-FID; GC–MS; Iberian pig subcutaneous fat; SPE