Industrially scalable complex coacervation process to microencapsulate food ingredients

Microencapsulation by conventional complex coacervation, though highly effective and achievable at the bench-scale, is challenging to scale-up because of the complexity of the process. A novel, industrially-scalable microencapsulation process by in situ complex coacervation during spray drying (the 'CoCo process') is introduced, where the multiple steps are collapsed into one, to form dry complex coacervated (CoCo) microcapsules by spray drying. The CoCo process was used to encapsulate D-limonene in CoCo microcapsules using alginate and gelatin as wall materials. Insoluble CoCo particles were produced without chemical cross-linking, with extents of complex coacervation of 75 +/- 6% and 64 +/- 6% for CoCo particles with and without D-limonene, respectively. Up to 82.7% of D-limonene was retained during spray drying; moreover, the CoCo matrix exhibited excellent barrier properties, retaining up to 80.0% of total D-limonene over 72-day storage in sealed vials at room temperature. Industrial relevance Commercialization of microencapsulation of bioactives by complex coacervation in agricultural and food applications is hindered by the high-cost and time-intensive multistep process consisting of emulsification, coacervation, shell hardening and drying. In this work, we overcome these limitations by developing an industrially scalable in situ complex coacervation process during spray drying ('CoCo process'). One-step complex coacervation during spray-drying opens the door to cost-effective, high-throughput, high-volume production of bioactive-containing microcapsules. The protective matrix microcapsules formed by this novel process stabilize and protect the bioactive, while allowing controlled release of the cargo for various applications in the food and many other industries.