Comparative Evaluation of Spray-Drying Versus Freeze-Drying Techniques on the Encapsulation Efficiency and Biofunctional Performance of Chenpi Extract Microcapsules.

Chenpi extracts (CPEs) are highly valued for their rich bioactive compounds and distinctive aromatic properties, but their environmental sensitivity poses stability challenges in food applications. In this study, CPE microcapsules were fabricated using corn peptide as the wall material, and the functional properties of spray-dried microcapsules (SDMCs) and freeze-dried microcapsules (FDMCs) were systematically characterized and compared. The results demonstrate that SDMCs exhibit superior characteristics compared to FDMCs, including reduced moisture content, lower hygroscopicity, enhanced solubility, smaller particle size, and a more uniform microstructure. Both FDMCs and SDMCs showed excellent thermal stability. The SDMCs of CPE encapsulated 93.45% of flavonoids, 90.35% of polyphenols, and 81.32% of sugars from the CPE, while also demonstrating exceptional retention of key terpene volatile compounds, particularly D-limonene (44.63%), γ-terpinene (45.18%), and β-myrcene (40.17%). In contrast, FDMCs exhibited stronger retention of alcohol-based volatile compounds. Furthermore, SDMCs displayed higher antioxidant and hypoglycemic activities, along with improved storage stability. In vitro digestion results reveal that SDMCs provide enhanced protection for CPE flavonoids and polyphenols, achieving bioaccessibility rates of 95.64% and 94.57%, respectively. These findings offer a theoretical basis for optimizing the drying processes in CPE microencapsulation, striking a balance between functional properties and flavor preservation for advanced food applications.