Phytochemical Compositions, Microencapsulation, and Antioxidant Activity of Aqueous Extract from Tithonia diversifolia Leaves

Tithonia diversifolia is a flowering plant from the Asteraceae family widely used in traditional medicine in Indonesia. This study aimed to evaluate the phytochemical composition of aqueous extract from T. diversifolia leaves and enhance the stability of its bioactive compounds through microencapsulation technology using chitosan as wall materials. Microencapsulation is a technique used to coat core materials with micro-sized protective layers to enhance stability, control release, protect from environmental factors, and improve handling properties. Based on LC-MS/MS analysis, aqueous extract from T. diversifolia leaves contains phytochemicals such as gilluone B, tagitinine A, thyrotundin, tadeonal, and stigmasterol glucoside. The microencapsulation of aqueous extract from T. diversifolia leaves plant resulted in encapsulation efficiency of 76.03 % with the optimum state of manufacture at a chitosan concentration of 0.05 % (w/v) and a stirring time of 90 min. The antioxidant activity of the aqueous extract from T. diversifolia leaves (70.43 mg/mL) and microcapsules (139.24 μg/mL). The bioactive compound releases were tested at pH 2.2 and 7.4 over 30 to 120 min. The findings showed a release of 53.36 % at pH 2.2 and 80.32 % at pH 7.4 at 120 min. After the release assay, the FTIR characterization showed changes in the structure of the functional groups, such as O-H, C-H alkanes, aromatic C=C, and N-H amines. The SEM shows differences in the surface morphology of the microcapsules before and after the release test. The microcapsules were initially spherical, but after the release test, their surface became uneven. This study confirms that microencapsulation can protect and release active ingredients in a controlled manner according to pH and release time. HIGHLIGHTS Tithonia diversifolia contains bioactives with antioxidant and antidiabetic potential. LC-MS/MS identified key compounds in aqueous leaf extract of Tithonia diversifolia. Chitosan-based spray drying microencapsulation enhanced extract stability and release. Antioxidant activity and pH-responsive release were improved in microencapsulated form. SEM and FTIR confirmed protective coating and functional group stability post-release. GRAPHICAL ABSTRACT