Design and characterization of β-cyclodextrin-encapsulated walnut peptide-calcium-zinc chelates: physical...

To overcome the application bottlenecks of low solubility, strong bitterness, and poor stability of walnut peptide‑calcium‑zinc chelates, this study developed a green microencapsulation method based on β-cyclodextrin(β-CD). By optimizing the mass ratio of the chelate to β-CD, the encapsulation efficiencies of calcium and zinc reached 81.60% and 85.56%, respectively, with an overall yield of 88.67%. Characterization confirmed encapsulation within β-CD cavities via hydrogen bonds and hydrophobic interactions. Additionally, microencapsulation significantly enhanced emulsification activity to 95.00%, foaming rate to 17.42%, and water solubility index by 58%, while reducing yellowing. The bitterness intensity of the microcapsules decreased by 25.7%, and thermal stability improved to 270 °C. Within pH 2-10, Calcium and Zinc solubility remained at 93.04%-85.53% and 97.91%-45.00%, respectively. In vitro digestion revealed intestinal retention rates of 54.78% for calcium and 40.27% for zinc after gastric digestion. Overall, This study enhances walnut protein value and aids in developing high bioavailability mineral supplements.