Determination of total safranal by in situ acid hydrolysis in supercritical fluid media: Application to the quality control of commercial saffron.

A procedure allowing hydrolysis reactions to be conducted in a dynamic supercritical-CO2 medium was developed for quantifying total safranal (viz. free safranal present in the sample+safranal resulting from picrocrocin hydrolysis), which are the main component of the essential oil and responsible for the characteristic aroma of saffron. The proposed method allows total safranal amounts over the ranges 0.05-1.5 mg mL(-1) to be determined. The standard deviation achieved was 2%. This method was applied to the determination of safranal in natural saffron samples. The results obtained were compared with the "safranal value" total index, which is widely used as a quality measure of saffron products. The comparison revealed that the proposed method provides useful information not contained in the safranal value, based on the fact that, some samples with a high "safranal index" contain low concentrations of safranal. The proposed method is very useful for quality control in commercial saffron samples.