Affiliations: Department of Process Engineering and Applied Science, Dalhousie University, Halifax, NS, Canada
Corresponding author: Marianne Su-Ling Brooks, Department of Process Engineering and Applied Science, Dalhousie University, PO Box 15000, Halifax, B3H 4R2 NS, Canada. Tel.: +1 902 494 6482; E-mail: Su-Ling.Brooks@dal.ca.
Abstract: BACKGROUND:The chemical instability of extracted anthocyanins (ACNs) limits their application and broader use as food colorants and health-promoting functional ingredients. Encapsulation technology can improve ACN stability and widen their potential applications. OBJECTIVE:The objective of this study was to optimize the microencapsulation of ACNs from haskap berries (Lonicera caerulea L.) in calcium-alginate particles by the extrusion/gelation method. METHODS:Response Surface Methodology (RSM) by Box-Behnken (BB) design was used for the optimization, followed by the desirability function. Three input variables were evaluated: concentrations of sodium alginate (x1, w/w %) and calcium chloride (x2, w/v %), and gelation time (x3, min). The responses were encapsulation efficiency (y1, %) and particle size (y2, μm). RESULTS:There was a good fit for the model where encapsulation efficiency was used as a separate response (R2 = 97.98%), however, the model for particle size did not give as good an agreement (R2 = 63.86%). The desirability function was used to optimize the two responses simultaneously and the optimum conditions were determined as 9.0% (w/w) alginate solution, 2.0% (w/v) CaCl2, and 10 min in the gelation solution. CONCLUSIONS:These results illustrate the application of RSM followed by a desirability function to optimize encapsulation parameters for a combined response, where several measures are considered.