Micro-encapsulation of Pacific white shrimp oil as affected by emulsification condition

Micro-encapsulation of shrimp oil using the mixture of whey protein concentrate (WPC) and sodium caseinate (SC) (1:1, w/w) as a wall material was carried out. The impact of core/wall material ratios (1:2 and 1:4, w/w) and homogenizing pressures (13.79 and 27.58 MPa) on characteristics and stability of emulsion was investigated. The size of emulsion oil droplets decreased with increasing homogenizing pressure (P < 0.05) but was not influenced by core/wall material ratio (P > 0.05). During the extended storage, particle size, flocculation factor (Ff) and coalescence index (Ci) of all emulsions sharply increased, especially in emulsions prepared at 13.79 MPa with a core/wall material ratio of 1:2 (P < 0.05). After spray drying, micro-encapsulated shrimp oil (MSO) prepared at 13.79 MPa with a core/wall material ratio of 1:2 had the larger size than others (P < 0.05). MSO prepared using a core/wall material ratio of 1:4 with homogenizing pressure of 27.58 MPa exhibited higher encapsulation efficiency (EE) (51.3%–52.8%) than others. Thus, both core/wall material ratio and homogenizing pressure directly affected micro-encapsulation of shrimp oil.