玫瑰茄花色苷微胶囊的制备及其特性表征OA

The calyx of roselle(Hibiscus sabdariffa L.)contains high levels of anthocyanins(HSA),but their utilization is limited due to instability.In this study,gum arabic,whey protein,and chitosan hydrochloride were used as composite wall materials to prepare roselle(Hibiscus sabdariffa L.)anthocyanin microcapsules(HSAM)through single-factor and response surface optimization experiments.The physicochemical properties and stability of HSAM were characterized by scanning electron microscopy(SEM),laser particle size a-nalysis,Fourier transform infrared spectroscopy,X-ray diffraction(XRD),and thermogravimetric analysis(TGA).Results showed that the optimal spray-drying conditions for HSAM were as follows:core-to-wall ratio of 1∶4,wall material concentration of 1.2％,and inlet air temperature of 171 ℃.Under these conditions,the encapsulation efficiency of HSAM reached(98.17±1.03)％,with a moisture content of(3.24±0.18)％.SEM analysis revealed that HSAM particles were uniform in size and significantly smaller than HSA,with 47.98％of particles having a diameter below 10 μm.The bulk density of HSAM powder was 0.259 g/cm3,the angle of repose was(44±0.5)°,and the viscosity was low,indicating good flowability.The composite encapsulant formed a new stable powder crystal structure with HSA and led to a reduction in the infrared spectral peaks of HSA,causing a shift in the XRD diffraction peaks of HSAM and a new diffraction peak appearing at 31.96°.TGA and photothermal stability studies demonstrated that HSAM exhibited improved heat resistance and UV-light stability,making it suitable for processing at temperatures below 150 ℃.This study provides new insights into encapsulation methods and processing parameters for the spray-drying of roselle anthocyanin microcapsules,facilitating the value-added utilization of roselle as an economically important crop.