Abstract:[Objective] This study prepared highly stable high internal phase emulsions (HIPEs) to encapsulate zeaxanthin, thereby improving the stability and expanding the food and pharmaceutical applications of zeaxanthin. [Method] HIPEs were prepared with the gelatin-chitosan suspension for encapsulation of zeaxanthin extracted from goji berries. Ultra-performance convergence chromatography (UPCC) was employed to separate zeaxanthin. Confocal laser scanning microscopy (CLSM) was employed to observe the emulsion structure. The rheological analysis was performed to characterize the emulsion, which was combined with the hydrogen peroxide and storage stability tests to evaluate the performance of encapsulation with HIPEs in improving the stability of zeaxanthin. [Result] The separation of zeaxanthin by UPCC needed only 2.14 min. The optimal preparation conditions for HIPEs were as follows: mass fractions of both gelatin and chitosan solutions were 0.50%, a gelatin-to-chitosan mass ratio of 4∶1, and pH 5. The CLSM results showed that HIPEs were successfully prepared with the gelatin-chitosan suspension. The rheological analysis results showed that HIPEs loaded with zeaxanthin exhibited solid-like elastic behavior, and their storage moduli were higher than loss moduli. The CLSM results showed that with the increase in the mass fraction of zeaxanthin, the oil droplets in zeaxanthin-loaded HIPEs were aggregated, extruded, and deformed, which gradually reduced the stability of the emulsion. The stability test results showed that compared with zeaxanthin directly dissolved in dodecane, the encapsulation in HIPEs effectively reduced the degradation rate of zeaxanthin and increased the retention rate after hydrogen peroxide treatment and storage at 4 ℃ by 17.98% and 90.09%, respectively. [Conclusion] Using HIPEs prepared with the gelatin-chitosan suspension for encapsulation helps to improve the stability and extend the shelf life of zeaxanthin, which provides a new strategy to overcome the limitations of zeaxanthin utilization.
