Odour Thresholds of Various Branched and Straight Chain Acetates

A series of straight chain and branched esters (ethyl acetate to 2-nonyl acetate) were purified by preparative gas chromatography and their odour thresholds were determined using sensory panel methods. Pentyl acetate and 2-butyl acetate had the lowest odour thresholds of the straight chain and branched acetates, respectively. Addition of a methyl group at the 1-position of the alcohol did not have a consistent effect on the odour threshold. For ethyl acetate, propyl acetate, butyl acetate and heptyl acetate the addition of a methyl group in the 1-position caused a decrease in the odour threshold; whereas for pentyl acetate, hexyl acetate and octyl acetate the addition of a methyl group in the 1-position caused an increase in the odour threshold.