SYNTHESIS OF SOME UNSATURATED LACTONES AND THEIR RELATIONSHIP TO DEEP-FAT FRIED FLAVOR

Seven unsaturated lactones, viz., the lactones of 4-hydroxy-nonenoic acid, with the double bond at the 2 and 3 position, respectively, 4-hydroxy-octenoic acid with the double bond at the 2 and 3 position, respectively, 5-hydroxy-4-nonenoic acid, 5-hydroxy-2-octenoic acid, and 5-hydroxy-2-undecenoic acid, were synthesized. Their chemical structures were confirmed by their infrared and mass spectra. Organoleptic evaluation indicated that γ-lactones with unsaturation at the 2 or 3 positions imparted a characteristic deep-fat fried flavor to cottonseed oil when added at 2.5 ppm. Furthermore, γ-lactones with unsaturation at the 3 position could improve the flavor of margarine and snack foods.