Comparative Technoeconomic Process Analysis of Industrial-Scale Microencapsulation of Bioactives in Cross-Linked Alginate

Abstract

<div>The food, chemical, and biotechnology industries offer many potential applications for calcium alginate microencapsulation, but this technique is largely confined to the laboratory bench due to scalability challenges. Scaling up the traditional external gelation method requires several costly unit operations. Alternatively, a consolidated process accomplishes alginate cross-linking in situ during spray-drying to form cross-linked alginate microcapsules (‘the CLAMs process’). This work examined the process economics of these two microencapsulation processes through technoeconomic analysis. Parallel batch process models were constructed in SuperPro Designer, initially for encapsulating emulsified fish oil. At all production scales examined, the capital investment and annual operating cost were lower for the CLAMs process. Modifying the external gelation process marginally improved the process economics, but costs remained elevated. The CLAMs process’ economic advantage stemmed from reducing the number of unit procedures, which lowered the equipment purchase cost and the dependent components of capital investment and annual operating cost. Upon modifying the models for microencapsulating hydrophilic cargo (e.g. enzymes, vitamins, microbial concentrates), the CLAMs process remained favorable at all cargo material costs and cargo loadings examined. This work demonstrates the utility of technoeconomic analysis for evaluating microencapsulation processes and may justify applying the CLAMs process at the industrial scale. </div>

Surfactant-Free d-Limonene Encapsulation in Spray-Dried Alginate Microcapsules Cross-Linked by In Situ Internal Gelation

“…The in situ internal gelation process provides a highly scalable method of generating dry calcium alginate microcapsules. 15 Although CLAMs are produced as a dry powder, in many prospective applications, CLAMs would ultimately be suspended in aqueous media. For example, when encapsulating a lipophilic bioactive compound for incorporation into foods, it may be important to consider the loss of bioactive cargo during cooking (e.g., sauces, baking mixes, etc.)…”

“…2 Unfortunately, most methods of forming calcium alginate microbeads are costly to perform at an industrial scale. 14,15 As an alternative, dry cross-linked alginate microcapsules (CLAMs) may be produced by in situ internal gelation during spray drying. This approach consolidates the number of unit operations required for alginate microbead production by accomplishing particle formation, alginate gelation, and drying in a single well-established unit operation.…”