EVALUATION OF 3,5-STIGMASTADIENE CONTENT OF EDIBLE OILS - COMPARISON BETWEEN THE TRADITIONAL CAPILLARY GAS-CHROMATOGRAPHIC METHOD AND THE ONLINE HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHY CAPILLARY GAS-CHROMATOGRAPHIC ANALYSIS

The quantitation of 3,5-stigmastadiene and other steroidal hydrocarbon s, commonly known as steradienes, is a valid tool for the recognition of refining (in particular bleaching) of edible oils; the evidence of this process is nowadays of a great interest due to growing market for ''virgin'', cold-pressed, ''natural'' oils. Due to the long time requ ired (about 4 hours) and the amount of solvents employed (about 650 mL ) to perform the official analysis, other methods have been recently p roposed, the most important of which involves high performance liquid chromatography coupled with capillary gas chromatography (HPLC-GC). In this study the results of ten oil samples, analysed by both the offic ial method and HPLC-GC, are reported and the two methods compared and discussed, for routine use, in terms of sample preparation, time of an alysis and setting up, difficulty and reproducibility.