Identifying Key Odor Compounds in Bourbon using Solvent-free Aroma Dilution Analysis and a Novel Software for interpreting GC-O Data

Stir Bar Sorptive Extraction (SBSE) coupled with gas chromatography-mass spectrometry and olfactory detection (GC-MS/O) allows for separation and identifi cation of aroma compounds in complex sample matrices with minimal sample preparation time. Aroma Dilution Analysis (ADA) is a solvent-free approach of Aroma Extract Dilution Analysis (AEDA) which employs a GC inlet system to split the carrier gas fl ow and thereby the injected sample to a desired ratio. The approach of ADA has been applied to direct immersion SBSE of bourbon samples for determination of fl avor dilution (FD) factors and identifi cation of key aroma-active compounds.

The gas chromatography system with a Thermal Desorption Unit (TDU 2) and Cooled Injection System (CIS 4) allowed two independent split ratios to be set. The product of the split ratios determines the overall dilution factor. The developed method allowed the determination of FD factors in a range from 1-201. Data generated by ADA was evaluated using a novel software that allows for the handling of GC-O intensity data along with the GC/MS data for identifi cation of key odorants in bourbon.