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.