Preparation and characterization of polyphenol-loaded microcapsules based on zeaxylated protein

Abstract

Pomegranate seeds are rich in polyphenols, known for their significant health benefits. In this study, we developed microcapsules to encapsulate pomegranate seed polyphenols (PSP) using a combination of zeaxylated protein (Zein) and chitosan (Cs). The optimization process involved a Zein to Cs volume ratio of 1:1, a chitosan concentration of 1.0 mg mL−1, and a polyphenol concentration of 2.0 mg mL−1. Scanning electron microscopy confirmed the formation of Zein/Cs/PSP complex coacervates, indicating the successful encapsulation. Fourier-transform infrared spectroscopy provided further evidence of electrostatic attraction between PSP and the Zein/Cs matrix. Differential scanning calorimetry analysis demonstrated the successful incorporation of PSP into the Zein/Cs wall material. Moreover, the encapsulated core material exhibited exceptional storage stability and retained its antioxidant activity. Notably, more than 85% of the encapsulated PSP remained intact after 5 h of simulated intestinal fluid digestion. This study underscores the potential of pomegranate seeds for comprehensive utilization in food engineering.

Keywords

• Polyphenols
• Microencapsulation
• Zein
• Stability
• In vitro digestion