Effect of pre-emulsified fish oil – as source of PUFA n−3 – on microstructure and sensory properties of mortadella, a Spanish bologna-type sausage

Conventional and low-fat cooked sausages (cursive) were prepared with fish oil as a source of n−3 polyunsaturated fatty acids. Fish oil was incorporated pre-emulsified with caseinates and water. Pre-emulsion was added in sufficient amounts to give fish oil levels of 1–6% in the final product. Lipid oxidation was determined (TBARs index) and instrumental measures of colour and texture were carried out. A sensory analysis was performed in which sensory parameters were evaluated by a hedonic test. There were no significant changes in TBAR values of final products being similar in both control and fish oil added sausages. In general terms, a slight increase in hardness and work of shearing were observed at the higher fish oil levels independently of the fat content. Sausages were analysed after 90 days of storage under refrigeration and similar results were observed. Microstructure of sausages was also studied by scanning electron microscopy (SEM) and a more compact structure was observed when the high levels were assayed. However, all sausages were well accepted when sensory quality was evaluated. Fat composition showed an increase in n−3 PUFA yielding a n−6/n−3 ratio close to 2, which is considered as healthier. For this, the incorporation of fish oil pre-emulsified seems to be a good option to include n−3 PUFA in cooked meat products, obtaining sensorially adequate and healthier stable sausages.