Calcium–Alginate–Inulin Microbeads as Carriers for Aqueous Carqueja Extract

Abstract

Carqueja (Pterospartum tridentatum) is an endemic species and various bioactive compounds have been identified in its aqueous extract. The aim of this study was to protect the natural antioxidants from the aqueous extract of carqueja by encapsulation in Ca-alginate microbeads and Ca-alginate microbeads containing 10% and 20% (w/v) of inulin. The microbeads produced by electrostatic extrusion technique had an average diameter from 625 μm to 830 μm depending on the portion of inulin. The sphericity factor of the hydrogel microbeads had values between 0.014 and 0.026, while freeze dried microbeads had irregular shape, especially those with no excipient. The reduction in microbeads size after freeze drying process (expressed as shrinkage factor) ranged from 0.338 (alginate microbeads with 20% (w/v) of inulin) to 0.523 (plain alginate microbeads). The expressed radical scavenging activity against ABTS and DPPH radicals was found to be between 30% and 40% for encapsulated extract, while the fresh extract showed around 47% and 57% of radical scavenging activity for ABTS and DPPH radicals, respectively. The correlation between antioxidant activity and the total phenolic content were found to be positive (in both assay methods, DPPH and ABTS), which indicate that the addition of inulin didn't have influence on antioxidant activity. The presence of inulin reduced stiffness of the hydrogel, and protected bead structure from collapse upon freeze-drying. Alginate-inulin beads are envisaged to be used for delivery of aqueous P. tridentatum extract in functional food products.

Development of gelatin-coated ι-carrageenan hydrogel capsules by electric field-aided extrusion. Impact of phenolic compounds on their performance

“…Again, this technology has mainly been exploited for the preparation of alginate-based microcapsules using calcium chloride as the gelling agent (Balanč, et al, 2016;Gryshkov, et al, 2014;Li, Kim, Chen, & Park, 2016;Prüsse, et al, 2008;Zhu, et al, 2009).…”

Chemometric evaluation of binary mixtures of alginate and polysaccharide biopolymers as carriers for microencapsulation of green tea polyphenols

“…[3,4] Binary mixtures of alginate and other polysaccharide bipolymers such as cellulose derivatives, starch or xanthan gum were also evaluated as the delivery systems of different active compounds. [1,[5][6][7][8][9][10][11][12][13] However, a systematic study of macromolecular interactions and variables that modulate those interactions and affect the encapsulation performance is required. Moreover, there is a lack of studies evaluating the interactions and potential of biopolymer mixtures of alginate and other hydrocolloids for the entrappment of naturally derived bioactive compounds, since most of the studies are still conducted with the purpose of encapsulating pharmaceutically active compounds.…”

Shape Tuning and Size Prediction of Millimeter-Scale Calcium-Alginate Capsules with Aqueous Core

“…Images of the capsules in air and water were captured by a digital camera (BL-SM500, Jinhua Oseelang Trade Co., Ltd., Jinhua, China). The diameter of the capsules (D, mm, using D min as the diameter D.) was measured with a digital micrometer and the shape of the capsules was quantified using the sphericity factor (SF) in Equation (1) [22,23]…”