LCGC: The Column, February 2021
Herbs and spices are used in many food preparation products. For food manufacturers, generating aroma profiles from the VOCs and SVOCs emitted by their products is important. The profiles are used for quality control and to identify components causing desirable or undesirable characteristics, for example.
However, the aroma profiles of spices are complex and consist of hundreds of odour-active compounds. Some compounds may have very low odour thresholds, which means that even those at trace level can have a major impact on the overall aroma. These trace compounds can be difficult to detect among more abundant components, so a highly sensitive analytical method is essential for quality assessments.
This article demonstrates that the sensitivity required can be achieved with the use of high-capacity sorptive extraction with trap-based focusing (which delivers a sharp, concentrated band of vapour to the GC). Coupled with enhanced separation by two-dimensional chromatography (GC×GC) and identification by time-of-flight mass spectrometry (TOF MS), the technique can give greater insight into the aroma profiles of curry powder. Also shown is how novel chemometric analysis can be used to compare the complex chromatograms and automatically discover the most significant differences between two curry powders of different quality.