Homogenization Pressure and Temperature Affect Protein Partitioning and Oxidative Stability of Emulsions

Abstract

Abstract The oxidative stability of 10 % fish oil‐in‐water emulsions was investigated for emulsions prepared under different homogenization conditions. Homogenization was conducted at two different pressures (5 or 22.5 MPa), and at two different temperatures (22 and 72 °C). Milk proteins were used as the emulsifier. Hence, emulsions were prepared with either a combination of α‐lactalbumin and β‐lactoglobulin or with a combination of sodium caseinate and β‐lactoglobulin. Results showed that an increase in pressure increased the oxidative stability of emulsions with caseinate and β‐lactoglobulin, whereas it decreased the oxidative stability of emulsions with α‐lactalbumin and β‐lactoglobulin. For both types of emulsions the partitioning of proteins between the interface and the aqueous phase appeared to be important for the oxidative stability. The effect of pre‐heating the aqueous phase with the milk proteins prior to homogenization did not have any clear effect on lipid oxidation in either of the two types of emulsions.