Effects of spray-drying temperature on the physicochemical properties and polymethoxyflavone loading efficiency of citrus oil microcapsules.

A polymethoxyflavone (PMF)-loaded citrus oil emulsion was prepared as microcapsules via spray-drying. The effects of spray-drying temperature ranges from 110 °C to 190 °C on the physical properties of the citrus oil microcapsule powder, encapsulation efficiency of PMF and the alteration of citrus oil aroma were investigated in this study. The microcapsule powder formed at 150 °C spray-drying temperature possessed low moisture content (1.7%, w.b.), high powder yield (51.4%), good particle integrity and the corresponding reconstituted emulsion had a small droplet size. The encapsulation efficiency of PMF in microcapsule powder decreased as the spray-drying temperature increased from 110 °C to 190 °C (75.8%→45.2%). Electronic nose and GC-MS measurements revealed that the spray-dried powder was close to the aroma of the original citrus oil, although partial volatile components were lost when spray-drying. The results from this study are expected to facilitate the development of PMF-loaded citrus oil microcapsule products for functional foods. Image 1 • The effect of spray-drying temperature on microcapsule properties was studied. • Microcapsule formed at 150 °C showed high yield, small size and good morphology. • The droplet size of reconstituted emulsion was related to microcapsule sizes. • Spray-drying temperature greatly affects aroma and PMFs encapsulation efficiency. • Citrus oil and PMFs encapsulated in microcapsule was proved by FTIR. [ABSTRACT FROM AUTHOR]