Comparison of HPLC and GLC techniques for the determination of the triglyceride profile of cocoa butter.
Current methods for the authentication of cocoa butter (CB) are mainly based on a knowledge of its triglyceride (TG) composition. The performances of capillary GLC and nonaqueous HPLC with an evaporative light-scattering detector (ELSD) for the quantification of TG of CB of different geographical origins were compared. Use of capillary columns coated with a polarizable stationary phase or two reversed-phase HPLC columns coupled in series efficiently separated the major TG species contained in CB. The velocity of the GLC carrier gas influenced the FID response factors of TG standard compounds, which were linearly related to the retention times of the analytes studied. Within a certain mass range the ELSD response of standard TG solutions did not deviate from unity to a greater extent, independent of the molecular structure of the TG species. The quantities of individual TG as obtained by both methods were in close agreement, and the precisions of the methods were also of comparable magnitude, so that either method can be applied to assess the purity of CB. Capillary GLC has the advantage of higher sample throughput due to a shorter run time and because the consumption of chemicals is negligible.
Buchgraber
M
M
European Commission, DG Joint Research Centre, Institute for Health and Consumer Protection, Food Products and Consumer Goods Unit, TP Ispra (VA), Italy.
Ulberth
F
F
Anklam
E
E
D002849:Chromatography, Gas / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004041:Dietary Fats / Q000032:analysis*; D008027:Light; D012542:Scattering, Radiation
D004041:Dietary Fats; C052387:cocoa butter