Functional dry fermented sausages manufactured with high levels of n-3 fatty acids: nutritional benefits and evaluation of oxidation

Dry fermented sausages including fish oil extracts rich in n-3 fatty acids were manufactured in order to obtain functional products, and their nutritional advantages and effects on oxidation process were compared with traditional ones. Modified products were manufactured with 5.3 g kg^-1 and 10.7 g kg^-1 of fish oil extract. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) contents per 100 g of dry fermented sausages were 0.15 g and 0.13 g for the lower rate of addition and 0.33 g and 0.26 g, respectively, for the higher rate, compared with only 0.01 g EPA and 0.03 g DHA in the control products. No significant differences were found in the other fatty acids. A decrease in the n-6/n-3 ratios from 16.14 in the control to 7.78 in batch A and 5.32 in batch B was achieved. Thiobarbituric acid reactive substances values were similar in control (0.31 ppm) and in batch A products (0.34 ppm) but increased significantly in batch B products (1.22 ppm). No statistical differences were observed among batches for the content of cholesterol oxidation products (2.36-2.43 (mu)g g^-1 fat) leading to similar percentages of oxidation. 7-Ketocholesterol, considered an indicator of oxidation, was not present in any sample. Values obtained for L* and hue (arctg b*/a*) were comparable with those of meat products. Although no effect was observed in cholesterol oxidation product formation and instrumental measurements of colour, the highest level of n-3 fatty acid seemed to accelerate the oxidation process significantly.