Quantification and potential aroma contribution of β-ionone in marine salt

Abstract

A methodology for quantification of β-ionone in marine salt was developed using the headspace solid phase microextraction and gas chromatography-quadrupole mass spectrometry (HS-SPME/GC-qMS). Quantification of β-ionone was achieved by linear regression from an analytical plot of pure standard using the target ion at m/z 177 by ion extraction chromatography (IEC). HS-SPME/GC-qMS combined with IEC mode allowed quantification of trace levels (ng/l) of β-ionone in marine salt aqueous solutions. The methodology developed presented a good linearity (R2 = 0.981) for the range of concentrations used (16 a 568 ng/l) and a good reproducibility (15%), with limits of detection and quantification of 9 and 29 ng/l, respectively. This methodology was applied to marine salt from diff erent geographical origins (Portugal, France, and Cape Verde). Estimated concentrations of β-ionone in marine salt varied from 241 to 888 ng/kg of salt. The highest values were found for Aveiro, in Portugal, and Guérande, in France, in environments surrounded by a large number of plant and algae diversity. However, in Castro Marim and Tavira (in Algarve, South of Portugal), this compound was not found. According to the odour threshold of β-ionone in water (30 ng/l), aqueous solutions with more than 100 g/l of marine salt can exhibit a violet odour. Similar conditions can occur in the ponds with higher levels of salinity of the traditional saltpans. This methodology proved to be a useful tool for screening and quantification of β-ionone, a compound shown to present potential contribution to marine salt aroma. Copyright © 2010 John Wiley & Sons, Ltd.