Shelf life study of healthy pork liver pate with added seaweed extracts from Ascophyllum nodosum, Fucus vesiculosus and Bifurcaria bifurcata

The effect of the addition of seaweed extracts from three brown algae species [Ascophyllum nodosum (AN), Fucus vesiculosus (FV) and Bifurcaria bifurcata (BB which are a great source of natural antioxidants, on the oxidative stability of refrigerated low-fat pork liver pates was studied. In the studied pates, half of pork fat was replaced with a mixture consisting of canola and high-oleic sunflower oil (75:25, v/v), thus improving their fatty acid profile in terms of polyunsaturated fatty acids (PUFA). In order to avoid the oxidation of PUFA in the new samples, seaweed extracts (500 ppm) were added. In addition, some samples were formulated with a synthetic antioxidant (BHT at 50 ppm) (BHT) and a control batch (CON) (without antioxidant) was also prepared, for comparison purposes. Thus, in total, five batches of liver pate were prepared: CON, BHT, AN, FV and BB. Pate samples were analyzed at 0, 45, 90, 135 and 180 days of refrigerated storage at 4 degrees C. The addition of seaweed extracts did not modify significantly (P > 0.05) the chemical composition or microbial characteristics of healthy pork liver pate, except for the protein content, which resulted in a significant increase (approximate to 2-3%) in the batches manufactured with addition of seaweed extracts compared to control samples. At the end of storage (180 days), L* values were significantly lower in the FV and BB batches than in the other batches. Moreover, the a* and b* values were also significantly lower in CON batches than in the samples with antioxidants added. Differences in oxidative parameters (conjugated dienes, TBARs and carbonyls) among batches were observed at the end of the storage time, showing samples with seaweed extracts a similar degree of protection against oxidation compared to BHT formulated samples. A decline of the volatile compounds was noted in all the batches during storage. The total volatile compounds at the end of the storage were significantly lower in BTH, AN, or BB batches than in control batches.