Characterization of the aroma compounds from stewing lamb

The aroma compounds from stewing lamb were analyzed.Simultaneous distillation and solvent extraction( SDE) was employed while the lamb was stewing.The extracts were analyzed by gas chromatography and mass spectrometry(GC- MS) as well as GC and Olfactometry( GC- O) in the detection of aroma extract dilution analysis(AEDA).A total of 142 volatile compounds were identified in GC-MS by search of NIST2014 mass spectra library and the comparison of retention index with those in the literatures. The identifications included aldehydes,ketones,alcohols,esters,carboxylic acids,sulfur compounds,nitrogen heterocycle,oxygen heterocycle and hydrocarbons,among which the amounts of aldehydes were the highest. The compounds of high percentages of peak areas were hexadecanal(18.82%),nonanal(11.67%),octadecanal(4.75%),hexanal(2.54%),octanal( 2.11%),etc.41 aroma- active compounds were identified in GC- O analysis by the comparison with results of GC- MS,and their retention indices,and odor characteristics with reported in literatures.Those of high flavor dilution factors(log_2FD≥7) were 3-(methylthio)- propanal,furfurylmercaptan,2- ethyl- 3,5- dimethylpyrazine,bis-( 2-methyl-3- furyl) disulfide,2,3- dimethylpyrazine,( Z)-2- nonenal,3- nonenal,12- methyltridecanal etc.,which were considered as the key aroma- active compounds of the stewing lamb.