Headspace SPME-GC/MS evaluation of ethanol retention in cooked meals containing alcoholic drinks

Abstract

A headspace SPME method in combination with GC/MS was used for the extraction, identification, and quantification of ethanol. The method used for sample preparation was simple. A fibre coated with 75 mu m CAR/PDMS film was chosen to extract the ethanol. Calibration curves that were constructed for ethanol spiked into blank samples followed linear relationships with highly significant (p < 0.001) correlation coefficients (r > 0.999). Coefficients of variation of <7.9% indicated that the technique was reproducible. The limits of quantification were registered at levels of parts per million. Quantification of ethanol was successfully performed in fish stew and beef bib by external standard method. Whereas standard addition method was used for quantification of ethanol in hunter rabbit, marinated grilled steak and industrial products that refer ethanol in the ingredients. Prediction of ethanol content of meals cooked with alcoholic drinks is possible for each type of cooked meals through knowledge of the initial amount of ethanol in ingredients. For fish stew cooked for 45 min in a covered pan where the wine was added in cold ingredients, alcohol retention was 30%, whereas for beef bib and hunter rabbit with red wine added to boiling ingredients and then cooked for 1 h in a covered pan the ethanol retention was 5%. These results indicate that care must be taken with meals cooked with alcoholic drinks since they can be consumed by the paediatric age group, abstinent alcoholics, or ethanol sensible individuals. The use of dealcoholised wine evaluated as a tasty alternative to the above mentioned groups.