Preparation of microcapsules containing antimicrobial lipopeptide from Bacillus amyloliquefaciens ES-2 by spray drying

•A optimal spray-drying technology is established for lipopeptide microcapsules.•Wall materials consisting of maltodextrin and porous starch are appropriate.•The antimicrobial lipopeptide retain a desired bioactivity after spray drying.•The lipopeptide microcapsules are in good spherical forms.•The technology is efficient for producing microcapsules of the lipopeptide.

Using a fermentation broth produced by Bacillus amyloliquefaciens ES-2 as a raw material, a preparation method for antimicrobial lipopeptide powders was developed. Antimicrobial lipopeptide microcapsules were obtained by a spray-drying process using maltodextrin and porous starch as composite wall materials. Optimal encapsulation conditions comprised a ratio of wall materials to the core material of 5%, a ratio of porous starch to maltodextrin of 1/9, a drying air flow of 70 m3/h and an inlet gas temperature of 220 °C, producing a high yield of microcapsules of 63.9 ± 0.5%. The lipopeptides retained their desired bioactivity and had a spherical form after spray drying, with an antimicrobial potency of 25711.3 ± 34.5 IU/g evaluated by the cylinder-plate method, and their preservation percent was about 81.5%. Because of its low cost, high efficiency, simplicity and easy of scale-up, the technology is expected to be efficient for producing antimicrobial lipopeptide powders and to be helpful in the application of antimicrobial lipopeptides as food additives.