Formation of the beef flavour precursors and their correlation with chemical parameters during the controlled thermal oxidation of tallow

Thermal oxidation of tallow was assayed by peroxide value (PV), p-anisidine value (p-AV), and acid value (AV), and the volatile compounds produced at different oxidation conditions were analysed by SPME-GC/MS. The accumulation of characteristic beef flavour precursors, such as hexanal, 1-octen-3-ol, (E,E)-2,4-decadienal and (E,E)-2,4-heptadienal, reached a maximum value when heated at 140 °C for 2 h with an air flow of 75 l/h per 100 g tallow, whereas at the same temperature PV and p-AV were both at high levels, and AV was relatively low. A correlation analysis of chemical parameters and volatile compounds showed that the beef flavour precursors were positively related to PV, and the off-flavour compounds were highly correlated to AV. Therefore, a moderate oxidation of tallow could be achieved via controlled thermal treatment.