Identification of characteristic flavour precursors from enzymatic hydrolysis-mild thermal oxidation tallow by descriptive sensory analysis and gas chromatography-olfactometry and partial least squares regression

Abstract

The "enzymatic hydrolysis-mild thermal oxidation" method was employed to obtain oxidized tallow. Nine beeflike flavours (BFs) were prepared through Maillard reaction with oxidized tallow and other ingredients. Volatile compounds of oxidized tallow and beeflike flavours were analysed by SPME/GC-MS. Six sensory attributes (meaty, beefy, tallowy, simulate, burnt and off-flavour) were selected to assess BFs. Thirty four odour-active compounds were identified to represent beef odour through GC-O analysis based on detection frequency method. GC-MS profiles of oxidized tallow were correlated with GC-O responses and sensory attributes of BFs using partial least squares regression modelling (PLSR). Twenty nine compounds were considered as the potential precursors of oxidized tallow. Among them, tetradecanoic acid, d-limonene, 1,7-heptandiol, 2-butyltetrahydrofuran, (Z)-4-undecenal, (Z)-4-decenal, (E)-4-nonenal and 5-pentyl-2(3H)-furanone were unique products generated from enzymatic hydrolysis-mild thermal oxidation of tallow, while hexanal, heptanal, octanal, nonanal, decanal, pentanal, acetic acid, butanoic acid, hexanoic acid, 1-heptanol, 1-octanol, 3-methylbutanal, 2-pentylfuran, γ-nonalactone, 2-undecenal, (E,E)-2,4-decadienal, (E,E)-2,4-nonadienal, (E)-2-nonenal, (E)-2-octenal, (E)-2-decenal and (Z)-2-heptenal were common products generated from thermal oxidation of tallow.