Microencapsulation of crystalline-methionine enclosed with gelatine and sodium alginate by spray-drying

Abstract

In the present study, a central composite rotatable design was used to optimise a microencapsulation process enclosing methionine with gelatine and sodium alginate by spray-drying. The results showed that the highest yield (92·2%) and efficiency (86·7%) of methionine microencapsulation were obtained, when the gelatine solution (40 g L−1)/sodium alginate solution (20 g L−1) ratio was 1 : 1, the methionine content was 15% and the feed speed was 35 mL min−1. In addition, the spray-dried microcapsules had a regular spherical shape and the crystalline methionine particles were enclosed by a wall system consisting of gelatine and sodium alginate. In vitro release study demonstrated that microcapsules could regulate methionine release and stimulate synchronous absorption of other amino acids to synthesise proteins. These observations suggest that methionine microencapsulation can be used to enhance the utilisation of amino acids and improve the application of methionine in aquaculture feed industry.