Formerly, say about 25 years ago, little was known about trace constituents present in concentrations below 0.1% (1,000 ppm) in natural isolates, such as essential oils, oleoresins, concretes or absolutes, Today it is possible to characterize compounds in concentrations less than one part per billion (0.001 ppm).
It is general knowledge that rather polar trace constituents, such as acids, phenols, nitrogen compounds and sulphur compounds, can have a characteristic impact on the overall sensory properties of the natural isolate.
Acidic compounds have been found in cassie absolute, costus root, patchouli and olibanum oil. These constituents have been reported to be important for the olfactive properties of the oils in each case.
