Extraction and identification of chemicals causing grassy odors in flavor profile analysis (FPA) reference standards

The extraction and identification of natural fresh grass odor standard was studied. Fresh grass was allowed to sit in water until it released its grassy components to the water. The resulting grassy samples were analyzed and the chemicals responsible for the characteristic odors identified by Flavor Profile Analysis and sensory GC analysis. Closed-Loop Stripping Analysis was used for the isolation of volatile non-polar compounds and Simultaneous Distillation Extraction was used for the isolation of more polar chemicals of moderate volatility. A primary grassy odor standard (cis-3-hexenyl acetate) and a secondary grassy odor standard (cis-3-hexen-1-ol) were identified by Mass Spectroscopy and Sensory GC. Dose-Response curves were plotted and corresponding odor threshold concentrations (OTC) were determined for the cis-3-hexen-1-ol the cis-3-hexenyl acetate. It was found that cis-3-hexenyl acetate was approximately 50 times more odorous than the cis-3-hexen-1-ol. The OTC of cis-3-hexenyl acetate was found to be between 1 and 2 μg/l.