Enhanced physical and oxidative stability of porcine plasma protein hydrolysates based oil-in-water emulsions by adding oxidized chlorogenic acid

Abstract

The stability of rapeseed oil-in-water emulsions prepared with porcine plasma protein hydrolysates (PPPH) created via limited-hydrolysis was investigated with respect to concentrations (0.1, 0.5, 1.0, and 1.5%, w/w based on PPPH) of oxidized chlorogenic acid (OCA) added after emulsification. Compared to the emulsion with an absence of OCA, the incorporation of OCA induced significantly higher absolute ζ-potentials, smaller particle sizes (d3,2 and d4,3), lower flocculation factors (Ff) and lower coalescence indices (Ci) (P < 0.05). However, the emulsion with 1.0% OCA exhibited the greatest physical stability (P < 0.05), as evidenced by the partition of PPPH among the emulsions. Moreover, incorporation of OCA into PPPH-stabilized emulsions displayed an increased oxidative stability via inhibition of both lipid and protein oxidation in a concentration-dependent manner (P < 0.05). These results suggest that OCA could induce cross-linking of PPPH, which likely provided a thicker interfacial film around each oil droplet. Therefore, the addition of OCA after emulsification could increase the physical and oxidative stability of PPPH-stabilized emulsions.