Core-shell microparticle encapsulation for pH-responsive and targeted delivery of lactoferrin and ferrous sulfate
Microgel beads of amidated low methoxy pectin and bovine lactoferrin were formed by external gelation of a water in oil emulsion with ferrous sulfate. The stability of the lactoferrin to gastric digestion and proteolysis by pepsin was determined by gel electrophoresis. The microparticles were then dispersed in chitosan and the resulting mixture was spray dried to form a shell that is insoluble at neutral pH conditions. The iron content of the microparticles without chitosan was 34 mg g-1 and with chitosan was 27 mg g-1. The addition of chitosan lead to reduced iron release at pH 7 (30%) compared to 60% iron release without chitosan, but did not prevent iron from releasing in acidic conditions (pH 1). The core shell microparticle system shows promise as an iron fortificant in food applications.