Physicochemical, Structural, and In Vitro Gastrointestinal Tract Release Properties of Sodium Alginate-Based Cryogel Beads Filled with Hydroxypropyl Distarch Phosphate as a Curcumin Delivery System

The objectives of this study were to produce sodium alginate (SA)-based cryogel beads filled with different concentrations (0, 0.4, 1.0, and 2.5%, w/w) of hydroxypropyl distarch phosphate (HDP) as a curcumin delivery system and to investigate the physicochemical, structural, and in vitro gastrointestinal tract release properties of the cryogel beads. According to FT-IR analysis, the formation of ionic crosslinking between SA and Ca²⁺ and the presence of HDP were found. XRD analysis demonstrated the successful encapsulation of curcumin in the beads by observing the disappearance of the characteristic peaks of curcumin. SEM analysis results revelated that SA-based cryogel beads exhibited a denser internal structure as the HDP concentration was increased. The encapsulation efficiency of curcumin in SA cryogel beads filled with HDP concentration from 0% to 2.5% was increased from 31.95% to 76.66%, respectively, indicating that HDP can be a suitable filler for the encapsulation of curcumin in the production of SA-based cryogel beads. After exposure to simulated gastric fluid (SGF) and simulated intestinal fluid (SIF), the release rate of curcumin was decreased as HDP concentration was increased. Accordingly, SA-based cryogel beads filled with HDP can be utilized for the delivery system of curcumin in the food industry.