Comparative Analysis of Different Natural Polymers as Coating Agents for Freeze-Dried Microencapsulation of Cosmos caudatus Kunth Compounds.

Abstract

The flavonoid compounds in C. caudatus K., known for their various benefits, are prone to quick degradation, leading to reduced biological activity. This research aimed to evaluate the types of coatings: gum Arabic (GA), maltodextrin (MD), and a combination of both (MDGA) in C. caudatus K. extract microcapsules. The extract of C. caudatus K. was encapsulated by different coating materials, GA, MD, and MDGA, and then dried using a freeze-drying technique. The evaluation was carried out by comparing the encapsulation efficiency values, biological activity, and release tests of each type of microcapsule coating. The research results indicate that coating agents have impacts significantly at p < 0.05 on efficiency encapsulation. Flavonoids were retained up to 79.67% by the MDGA coating, compared with 72.8% and 47.66%^a retained by single GA and MD coatings, respectively. The results of the encapsulation efficiency are supported by the results of characterization using a scanning electron microscope (SEM), where MDGA has rounder shapes with smoother surfaces compared with a single coating alone, like GA or MD. In addition, by particle size analysis using a particle size analyzer (PSA), the average sizes of MDGA, GA, and MD microcapsules were shown at 154.13 µm, 152 µm, and 166.81 µm, respectively. The three microcapsules showed an order of activities as MDGA > GA > MD coatings in alpha-amylase inhibition assay. Similar results were also shown in the antioxidant assay, which demonstrated that the three microcapsules had moderate antioxidant activities, again in the order of MDGA > GA > MD. The three different coating types showed greater release at pH 7.4 compared to those at pH 2.2 in the controlled release test, which ran from 30 to 120 min. In summary, freeze-drying microencapsulation using biodegradable polymers was identified as a viable method for harnessing the health benefits of C. caudatus K. extracts. This process produced a convenient powder form that could be used in drug delivery systems. The use of MDGA mixed coating resulted in better impact based on %EE value and biological activity, as well as improved characteristics of microcapsules compared with single coating.