I am particularly interested in volatile compounds presents in food products. I would appreciate any information you could give me, specially if there are online-available databases.
There are couple of resources available besides Leffigwell.com:
1. Devos et al (1990) book is excellent. (Devos, M., Patte, F., Roualt, J., Laffort, P. and Van Gemert, L.J. (1990) Standardized Human Olfactory Thresholds.
Then, you could also consider additional resources:
2. Y. Nagata, Measurement of odor threshold by triangle odor bag method, Bull.
Jpn. Environ. Sanit. Center 17 (2003) 77–89. This reference is also available here:
We have just launched a new digital resource for odour thresholds, clearly classified as to quality levels. See also a report that enters into quality of OT values: https://www.rivm.nl/bibliotheek/rapporten/609200001.pdf
It may not be the ideal database, but I personally like GoodScents.com.
If you have a particular compound of interest, you can put in a search and get some odor and taste descriptors, recommended usage level and a qualitative, 'high,' 'medium,' 'low,' impact level.
Abraham, Michael H., Ricardo Sánchez-Moreno, J. Enrique Cometto-Muñiz, and William S. Cain. “An Algorithm for 353 Odor Detection Thresholds in Humans.” Chemical Senses 37, no. 3 (March 1, 2012): 207–18. https://doi.org/10.1093/chemse/bjr094.