Development and characterization of controlled released polyphenol rich micro-encapsulate of Murraya koenigii bark extract

Electrostatic extrusion-based microencapsulation technique is recognized for improving delivery, stability, and bioavailability of polyphenols. In the present study, extracts of Murraya koenigii (L.) Spreng., bark, fruit pulp, fruit seed, and leaves were analyzed for polyphenolic content. Bark extract exhibited maximum phenolics (98.96 +/- 0.95 mu g GAE/mg), flavonoids (24.05 +/- 1.52 mu g RU/mg), and antioxidant activity, and thereby, utilized for microencapsulation. Chitosan and calcium chloride (Ca+) concentrations and microencapsulator parameters; frequency, electrode potential, and nozzle size were also optimized. Maximum sphericity and structural stability were observed in three alginate-chitosan systems S-1; 5% of alginate, 10% of CaCl2, 1.25% of chitosan, 2.5% of ascorbic acid S-2; 5% of alginate, 10% of CaCl2, 0.5% of chitosan, 2.0% of ascorbic acid, and S-3; 5% of alginate, 5% of CaCl2, 0.5% of chitosan, 2.0% of ascorbic acid. Study revealed the maximum encapsulation efficiency (88.92%) and controlled release in S-1 system beads and scanning electron microscopy (SEM) showed lesser irregularity in shape after lyophilization. Ultra performance liquid chromatography (UPLC) analysis revealed the stable delivery of myricetin (1.75 mu g/mg) and cinnamic acid (2.07 mu g/mg) in simulated intestinal phase during in vitro conditions. While, particle size distribution and rheological properties also supported the higher polyphenolic encapsulation in S-1 system beads. Practical applications In the current scenario, food and health industries are widely utilizing the dietary polyphenols for delaying the cellular oxidation and preventing diseases. However, molecular stability of polyphenols is affected by various factors, like pH, temperature, light, moisture, and some processing techniques. Encapsulation can therefore, act as a delivering agent for controlled release of these polyphenols. Hence, in the present study, a stable sodium alginate-chitosan gel beads were prepared by optimizing various extrusion parameter. In vitro gastrointestinal studies showed a good stability and controlled release of major polyphenols of Murraya koenigii bark extract. While, characterization using rheology, dynamic light scattering (DLS), and scanning electron microscopy (SEM) of phenolic enriched beads also proved the relation between morphological dependency of phenolic binding and release. Current finding will help the food industries to enrich the dietary polyphenol extracts in gel-based food products.