The effect of free fatty acids on the odour of pork investigated by sensory profiling and GC-O-MS

The precursors for fried flavour in pork include fatty acids, carbohydrates and amino acids. The aim of this study was to investigate the effect of free fatty acids on the odour of a pork model system and to identify important aroma compounds detected by GC-O. The odour of heat-treated minced pork to which a free fatty acid had been added was assessed by a sensory panel. The following fatty acids were compared with a control meat sample: C18:1, C18:2 omega 6, C18:3 omega 3, C18:3 omega 6, C20:4 omega 6 and C22:6 omega 3. The fatty acids were added at either 40 or 100 times the natural level present in the minced pork. The addition of fatty acids reduced the intensity of the meaty odour. C18:2 omega 6 resulted in an oily odour, while C18:3 omega 3 and C22:6 omega 3 resulted in a fishy odour. The effect of C18:1, C18:3 omega 6 and C20:4 omega 6 on the odour was smaller. An aroma analysis was performed by GC-O-MS, using eight panellists, on a control meat sample and on meat samples after addition of C18:2 omega 6, C18:3 omega 3 and C22:6 omega 3. Sixty-two odour-active areas were detected. An underlying compound was identified in 38 areas. A large number of long-chain aldehydes, alcohols and ketones were detected in the sample to which C18:2 omega 6 had been added, and this might explain the oily odour of these samples. Especially 1-penten-3-ol was detected in the samples to which C18:3 omega 3 and C22:6 omega 3 had been added, and this might explain the fishy odour of these samples.