Optimization of Microencapsulation of Flavonoids from Red Raspberry Seeds and Its Simulated Gastrointestinal Digestion in Vitro

Using red raspberry seeds flavonoids as the core material, gelatin and carboxymethyl cellulose as wall materials, the red raspberry seeds flavonoids microcapsules were prepared by optimizing the complex agglomeration method through single factor and response surface tests. The prepared microcapsules were researched on physicochemical properties and its in vitro releasing behavior. The results showed that the optimal process parameters were as follows:Core/wall material quality ratio 1:4.6 (w:w), wall material concentration 1% and reaction temperature 46℃, the embedding rate could reach 92.38%. The moisture content, repose angle, solubility, particle size and glass-transition temperature of the microcapsules were 5.26%, 31.3°, 91.54%, 546 nm and 145.75℃, respectively. The encapsulated flavonoids had good solubility and stability. Simulated gastric digestion 2.5 h and intestinal digestion 3.0 h, the release amout of flavonoids before and after microcapsulation were 14.23, 5.02 mg/g and 27.79, 12.62 mg/g.These results conclusively suggested that encapsulated flavonoids by this process could protect the flavonoids, and improve its stability and sustained release behavior.