Influence of content of nutritionally essential fatty acids on keeping quality of fresh pork

Current recommendations for consumers suggest the dietary ratio of n-6 to n-3 polyunsaturated fatty acids should be 5:1. Manipulation of fatty acid profile of pig meat is comparatively straightforward, thus production of pork that approaches the ‘optimum’ is realisable. However, associated with this is a significant risk of deterioration in both keeping and eating quality, following oxidative rancidity. The objective of the trial was to manipulate total n-6 (linoleic, C18:2) and n-3 (linolenic, C18:3) levels of adipose tissue fatty acids, whilst keeping the ratio relatively constant at 5:1, giving levels of 180, 150 and 120g C18:2 /kg adipose tissue with concomitant levels of 36, 30 and 24g C18:3 /kg adipose tissue. Pork (lean) was subjected to physical and biochemical assessment.Four isocaloric and isonitrogenous diets were formulated. Diets 1 to 3 contained progressively less soya bean oil (42.3, 33.9 and 25.6 g/kg) and linseed oil (8.3, 5.0 and 1.7 g/kg) and progressively more maize starch (0, 30.8 and 61.6 g /kg) with ‘himod’ powder as an inert filler (38.3, 19.1, Og/kg) respectively for diets 1, 2 and 3.