Effect of differently sized O/W emulsions loaded with rosemary extract on lipid oxidation in cooked emulsion-type sausages rich in n-3 fatty acids

Meat products enriched with n-3 fatty acids are highly susceptible to lipid oxidation. Therefore, the purpose of this study was to retard lipid oxidation by oil-in-water emulsions (10% (w/w) Miglyol 812 N, 2% (w/w) Tween 80) loaded with rosemary extract and to evaluate the impact of droplet size (d43 = 190-5700 nm) in cooked emulsion-type sausages containing 1% encapsulated fish oil (10% (w/w) oil, 2% (w/w) Tween 80). Mechanically prepared emulsions were physically stable during the 35-day study and neither coalescence nor Ostwald ripening occurred. Moreover, the Miglyol oil-in-water emulsion without incorporated antioxidant (o/wcontrol) was slightly flocculated. The oxidative stability of the sausages containing 50 mg/kg encapsulated rosemary extract improved significantly compared to the control sausages during the first 21 days stored at 7 °C. However, from day 21-35, the primary and secondary oxidation products increased significantly in the sausages with incorporated antioxidants, concurrently no differences in the antioxidant effectiveness of differently sized emulsions loaded with rosemary extract were observed for thiobarbituric acid reactive substances, propanal and hexanal. Consequently, there is no need for the industry to decrease the droplet size of oil-in-water emulsions loaded with rosemary extract to enhance the oxidative stability of these products.