Enhancing the stability of Centella asiatica bioactive compounds via ultrasound-assisted extraction and microencapsulation via ionotropic gelation.

Centella asiatica extract is a potential source of bioactive compounds that are susceptible to degradation under processing and practical application conditions. Therefore, microencapsulation technology is an effective solution to protect the active compounds and improve their stability and release from Centella asiatica extract. This study aims to determine the optimal extraction conditions for Centella asiatica extract using ultrasound and to develop an alginate microencapsulation system for Centella asiatica extract using the ion-gel method, capable of protecting and preserving the bioactive compounds. The research results showed that the extraction process achieved the highest efficiency when using 80% ethanol, with a material:solvent ratio of 1:80, and sonication at 50 °C for 45 min. Under these conditions, the extracts obtained had total polyphenol (TPC) and total flavonoid (TFC) content of 379.537 ± 1.223 mg GAE/g DW and 154.258 ± 0.467 mg QE/g DW, respectively, demonstrating that the ultrasonic method contributed to increasing the ability to break down plant tissue and release active ingredients effectively. In the microencapsulation process, the gel formation conditions using 2% alginate, with an ultrasonic vibration amplitude of 50% for 5 min, resulted in a uniform microencapsulation system with a microencapsulation efficiency of 83.84%, stable particle structure, and suitable hardness and swelling. After 1 month of storage, the microencapsulation system maintained good quality, demonstrating the effective protection and stabilization of active ingredients by the alginate material.