The key aroma compounds in heated sheep tallow were analyzed by solvent-assisted flavor evaporation (SAFE) combined with gas chromatography-mass spectrometry (GC-MS) and gas chromatography-olfactometry (GC-O). Based on NIST2011 database search, retention index, and comparison with authentic standards, 58 volatiles were identified by GCMS, among which 2, 3-butanediol, acetic acid, acetoin, propanoic acid, hexanoic acid, and 2-hexanol were more abundant. A total of 37 odor activity regions were found by aroma extract dilution analysis (AEDA) combined with GC-O. Totally, 37 odorants were identified, among which (E,E)-2,4-heptadienal, (E)-2-nonenal, (E,E)-2,4-octadienal, (E)-2-decenal, (E,Z)-2,4-decadienal, (E,E)-2,4-decadienal, 2-heptanol, trimethylpyrazine, 4-methylthiazole, 3-(methylthio) propanal, dihydro-5-methyl-2(3H)-furanone, and 4-ethylphenol, with higher flavor dilution (FD) values (log₂FD ≥ 4), were considered to be the key aroma compounds in sheep tallow. These results can provide a basis for the utilization of sheep tallow in the food industry and the preparation of mutton flavorings.

Roasted lamb chops were prepared by superheated steam roasting (SSR) and direct roasting (DR). To explore the formation mechanism of flavor substances, descriptive sensory analysis (DSA), an electronic nose (E-nose) system, head-space solid phase microextraction combined with gas chromatography-mass spectrometry (HS-SPME-GC-MS), and gas chromatography-olfactometry (GC-O) were employed to analyze the sensory properties, fatty acid composition and volatile compounds of the SSR and DR samples. The DSA and E-nose results consistently revealed variations in aroma profiles between the two samples. The DR sample showed stronger roasted, fatty, and mutton-like aroma (P < 0.05). A total of 44 volatile compounds were identified from both samples. The contents of aldehydes, alcohols, and nitrogen-containing compounds in the DR sample were higher than those in the SSR sample. Totally 35 aroma-active compounds were identified by aroma extract dilution analysis (AEDA) combined with GC-O analysis, among which, decanal, hexanal, octanal, nonanal, (E,Z)-2,6-nonadienal, (E,E)-2,4-decadienal, (E,E)-2,4-nonadienal, 1-octen-3-one, 3-octen-2-one, 2-nonanone, heptanoic acid, 2-methylpyrazine, 3-(methylthio)propanal, benzothiazole, and 2-pentylfuran were the major ones. The types of aroma-active compounds in the two samples were similar, but their flavor dilution (FD) factors were different. Compared with the SSR sample, the content of total fatty acids in the DR sample significantly increased (P < 0.05). The content ratio of polyunsaturated fatty acids to saturated fatty acids (PUFA/SFA) in the DR sample was 40.66%, indicating higher nutritional value. Pearson’s correlation analysis showed that the oxidative degradation of unsaturated fatty acids such as oleic acid, linoleic acid, linolenic acid, and eicosenoic acid was closely related to the formation of the characteristic flavor in roasted lamb chops.