Microencapsulation of Chenpi extract with soy oligopeptides: enhanced retention of flavor compounds and improved...

Chenpi extract (CPE) is rich in polyphenols, flavonoids, and volatile flavor compounds, and possesses numerous healthy biological effects. However, the low stability and bioaccessibility of CPE significantly limits its application in food development.

In this study, CPE microcapsules were prepared using soybean oligopeptide (SOP), maltodextrin (MD), soybean protein isolate (SPI), and citrus insoluble dietary fiber (CIDF) as the encapsulants. The successful encapsulation and thermal stability of the CPE microcapsules were confirmed through structural, interaction characterization, and thermal analyses. Soybean oligopeptide encapsulated 97.89% of the total flavonoids and 95.97% of the total polyphenols in CPE, which was significantly higher than the other three materials (MD, SPI, and CIDF). Soybean oligopeptide also showed good retention capacity for volatile flavor compounds in CPE, especially d-limonene (47.67%), γ-terpinene (49.65%), n-octanal (57.38%), and β-Myrcene (44.65%). The in vitro digestion results showed that the CPE loaded by SOP was more stable during simulated digestion compared with the CPE loaded by the other three materials. The bioaccessibility of total flavonoids and total polyphenols in CP-SOP was 96.64% and 88.95%, respectively.

Overall, these results highlight that SOP is a better carrier for CPE microcapsules, and the distinct characteristics of SOP could significantly improve the quality of Chenpi-related functional food. © 2024 Society of Chemical Industry.