The invention relates to a gamma-undecenolactone of formula (i), wherein a lactonic cycle can carry an unsaturation between carbon No. 2 and carbon No. 3 and is preferably saturated, RI is a possibly substituted C7 alkenyl or alkynyl group having at least one unsaturation, and preferably RI is an CH2═CH—CH2—CH2—CH2—CH2—CH2 group, the gamma-undecenolactone contains an asymetric carbon in position 4 having (R) or (S) configuration. The biosynthesis of the gamma-undecenolactone and the use thereon for perfumery and for a food flavoring agent are also disclosed.