Automated Analysis of Volatile Flavor Compounds

Volatile organic compounds present in foods have a significant impact on flavor quality. The analysis of these compounds can be quite difficult, since the sample is often not amenable to direct GC injection, and the volatiles may be present in very low concentrations while still being important to flavor. The technique of dynamic headspace sampling was used for the isolation and concentration of volatiles prior to analysis by gas chromatography. Samples, which may be heated, are purged with an inert gas, sweeping any volatile compounds present out of the sample. The volatiles are trapped on Tenax, which is then thermally desorbed and backflushed to inject the sample into the GC. Using new instrumentation, this method was fully automated. Samples run include fruits, fruit products, edible oils, and oil-based foods. Detection limits in the low part-per-billion range were obtained with 2-9% reproducibility.