| Plant | Low PPM | High PPM | StdDev | *Reference | |
|---|---|---|---|---|---|
| Pyrus communis | Plant | -- | -- | * | |
| Ribes nigrum | Fruit | -- | -- | List, P.H. and Horhammer, L., Hager's Handbuch der Pharmazeutischen Praxis, Vols. 2-6, Springer-Verlag, Berlin, 1969-1979. | |
| Satureja cuneifolia | Shoot | -- | 20.0 | 2.6 | Tumen, G. 1991. The Volatile Constituents of Satureja cuneifolia. J. Ess. Oil Res., 3: 365-366. |
| Solanum tuberosum | Plant | -- | -- | * | |
| Zingiber officinale | Essential Oil | -- | -- | Kameoka, H. and Nakai, K. 1987. Components of essential oil from the root of Glycyrrhiza-glabra. Nippon Gogeikagaku Kaishi 61(9): 1119-1122. | |
| Zingiber officinale | Rhizome | -- | -- | * |