Effects of spray-, oven-, and freeze drying on the physicochemical properties of poorly aqueous-soluble xanthone encapsulated by coacervation: A comparative study

Abstract

This study aims to compare the effect of different drying techniques (oven-, spray-, and freeze drying) on xanthone, a poorly aqueous-soluble bioactive compound, encapsulated by coacervation using gelatin and gum Arabic. Free-flowing spherical shape powders were produced except for freeze drying that resulted in a stratified cell-like structure. Fourier transform infrared spectroscopy confirmed no interaction between xanthone and wall material. Among the drying techniques, spray dried resulted in the lowest yield and encapsulation efficiency (EE) but the highest improvement (ninefold) in xanthone aqueous solubility from 2.6 µg/mL to 22.32 ± 5.99 µg/mL. Freeze drying resulted in the highest encapsulation yield (75.4%) and EE (68.2%). Besides the solubilizing effect of wall material, the drying technique demonstrates a significant effect (p < 0.05) on xanthone’s aqueous solubility. In summary, this study provides insights into the influence of drying techniques on the physicochemical properties of xanthone coacervates, which has potential usage in food and pharmaceutical industries.

Keywords:

• Xanthone
• drying technology
• solubility enhancement
• coacervation
• microencapsulation
• aqueous solubility

Acknowledgment

The authors offer gratitude to Yiming Biological Products (Taixing, China) for commercial microbial transglutaminase (TG).

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.

Additional information

Funding

The authors acknowledge the Ministry of Science, Technology, and Innovation, Malaysia (E-Science research grant 06-02-10-SF0092), and the School of Science, Monash University Malaysia for supporting this study.