Characterization of Volatile Flavor Compounds in Dry-Rendered Beef Fat by Different Solvent-Assisted Flavor Evaporation (SAFE) Combined with GC–MS, GC–O, and OAV

To comprehensively understand the volatile flavor composition of dry-rendered beef fat, solvent-assisted flavor evaporation (SAFE) with four extraction solvents (dichloromethane, pentane, ethyl ether, and methanol) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactormetry (GC-O) were performed. GC-MS analysis found 96 different volatile compounds in total using the four extraction solvents. According to the GC-MS results and the heat map and principal component analysis (PCA), most of the volatile compounds resulted from dichloromethane and pentane extraction, followed by ethyl ether. Methanol extraction found a few volatile compounds of higher polarity, which was supplementary to the analysis results. Moreover, GC-O analysis found 73 odor-active compounds in total using the four extraction solvents. The GC-O results found that pentane and dichloromethane extraction had a significantly larger number of odor-active compounds than ethyl ether and methanol extraction. This indicated that pentane and dichloromethane were more effective solvents for the extraction of odor-active compounds than the other two solvents. Finally, a total of 15 compounds of odor-active values (OAVs) ≥ 1 were determined to be the key aroma compounds in the dry-rendered beef fat, including 2-methyl-3-furanthiol, 3-methylthiopropanal, (E,E)-2,4-nonadienal, 12-methyltridecanal, and 1-octen-3-one.