Unequivocal Identification of 1-Phenylethyl Acetate in Clove Buds (syzygium aromaticum (L.) Merr. & L.M.Perry) and Clove Essential Oil.

The natural occurrence of 1-phenylethyl acetate (styrallyl acetate) was confirmed in commercially available dried clove buds and also in the hydrodistilled oil from clove buds. This confirms previous reports and other anecdotal evidence for its occurrence in nature.

Identification of prenyl ethyl ether as a source of metallic, solvent-like off-flavor in hazelnut.

In a large batch of ground hazelnuts, a metallic, solvent-like off-note was detected. In this investigation, the volatiles from the batch showing off-notes were compared to a batch without off-notes. On the basis of gas chromatography (GC) sniffing and instrumental analysis, a terpenoid compound, prenyl ethyl ether, was identified as a key contributor to the off-note. The compound was quantified, and its contribution to the metallic, solvent-like off-flavor was confirmed by spiking experiments and sensory evaluation. Analytical and sensory experiments found that the off-note was still present in hazelnut cakes. Fat oxidation did not contribute to the off-flavor. Analysis of market products demonstrated the correlation between the identified terpenoid and the off-flavor. It is assumed that fungi are involved in off-flavor formation.