Effect of different encapsulating agent combinations on physicochemical properties and stability of microcapsules loaded with phenolics of plum (Prunus salicina lindl.)

Microencapsulation improves the bioavailability and stability of phenolic compounds, while encapsulating agents affect the quality of microcapsules. In order to improve the stability and application range of phenolics from plum (Prunus salicina Lindl.), microencapsulation was applied by using spray drying method. The present work evaluated the influence of maltodextrin/gum arabic (MD/GA),maltodextrin/gelatin (MD/GEL), maltodextrin/chitosan (MD/CHI) and maltodextrin/β-cyclodextrin/gum arabic (MD/β-CD/GA) on physicochemical properties and stability of microcapsules loaded with phenolics of plum. These four kinds of encapsulating agent combinations significantly improved the product yield and storage stability of the microcapsule powder, but there were differences among them in microencapsulated efficiency, microstructure and color. Using encapsulating agents markedly increased the glass transition temperature (Tg) of spray-dried powders, and Tg of the powder was positively correlated with its product yield. Furthermore, the powder prepared by MD/CHI had the best stability, and the retention rate of total phenol was 94.60% after storage at 25 °C for 60 days. The powder prepared by MD/GA and MD/β-CD/GA preferably retains the original red color of plum, and can be used as natural nutrient red pigments in the food industry.