Optimization of the Microencapsulation of Anthocyanins from Haskap Berries (Lonicera caerulea L.) in Ca-Alginate Beads for Oral Delivery Giovana B. Celli, Amyl Ghanem, and Marianne S. Brooks Dalhousie University, Halifax, NS, B3H 4R2, Canada [email protected] ABSTRACT SUMMARY The aim of this study was to optimize the encapsulation of anthocyanins from haskap berries (Lonicera caerulea L) in Ca-alginate beads using Box-Behnken (BB) design. Three variables were evaluated: sodium alginate (SA) and calcium chloride (CC) concentrations, and time (T) that the beads remained in the crosslinking solution. Encapsulation efficiency ranged from 17.97 to 63.12%. The mathematical model showed a high coefficient of determination (R 2 = 97.98%) and the optimum conditions for the encapsulation were as follows: 9% (w/w) alginate, 2% CaCl 2 (w/v) and 10 min in the crosslinking solution. INTRODUCTION Studies have shown that the consumption of a variety of berries can be associated with a number of positive health-related effects, such as reduction of cancer [1]. Haskap berries have high levels of anthocyanins and are recognized as the elixir of life by Japanese aborigines [2]. These fruits have a pleasant tart taste that is not often appealing to all consumers, which could limit the consumption of fresh fruits. In addition, isolated anthocyanins are very susceptible to degradation by pH, temperature, light, etc. Encapsulation is an effective technique to increase the stability of these compounds and for the elaboration of value-added products and nutraceuticals. This work aimed to optimize the microencapsulation of anthocyanins extracted from haskap berries in Ca-alginate beads. The optimized encapsulate will be later evaluated by its thermal stability in comparison to the extract. This data prepares the way to determine the best applications of these encapsulates in food processes. EXPERIMENTAL METHODS Freeze dried haskap berries (var. Indigo gem) were extracted with 80% ethanol (v/v) (0.5% formic acid, v/v) in a ratio of 1:25 (g/mL) under stirring at 600 rpm for 10 min at room temperature. The extract was filtered and evaporated at 40 ºC under vacuum. BB design was used to optimize the encapsulation of this extract in Ca-alginate beads using the following variables and levels: low viscosity sodium alginate (9, 9.5, 10%, w/w) and calcium chloride concentrations (2, 2.5, 3%, w/v, acidified with 2% (v/v) acetic acid glacial), and time in the crosslinking solution (10, 20, 30 min) (Table 1). The pH of the extract was adjusted to >4.5 before addition to the alginate solution (extract:alginate solution ratio 1:4 by volume) and extruded into the crosslinking solution through a 23G needle using a peristaltic pump (average flow rate of 0.3 mL/min). The encapsulation efficiencies (EE, %) were indirectly assessed by measuring the total anthocyanin content in the recovered CaCl 2 solution (amount non-entrapped) by a colorimetric method [3]. RESULTS AND DISCUSSION An example of beads with encapsulated extract is shown in Figure 1. Figure 1 – Beads produced with 10% (w/w) alginate after adjusting the pH and extruded to an acidified 3% (w/v) CaCl 2 solution (ratio extract:alginate solution 1:19 by volume) (left – fresh beads; right – after drying overnight at room temperature, in the dark) The EE% results are shown in Table 1. Table 1 – BB design matrix used in this study N. Alginate (%) CaCl 2 (%) Time (min) EE (%) 1 9.0 2.0 20 42.25 2 10.0 2.0 20 46.20 3 9.0 3.0 20 17.97 4 10.0 3.0 20 50.66 5 9.0 2.5 10 57.84 6 10.0 2.5 10 63.12 7 9.0 2.5 30 39.39 8 10.0 2.5 30 62.27 9 9.5 2.0 10 51.85 10 9.5 3.0 10 46.50 11 9.5 2.0 30 36.79 12 9.5 3.0 30 32.32