微波-超声波辅助制备木薯淀粉纳米颗粒及其特性表征

以广西特色资源木薯淀粉为原料,微波超声波辅助制备了木薯淀粉纳米颗粒。采用动态光散射技术考察了淀粉乳浓度、微波超声波处理功率、微波超声波处理时间、料醇比(淀粉溶液与乙醇体积比)、淀粉溶液的滴加速率、滴加淀粉溶液的过程中微波超声波功率对纳米颗粒尺寸及多分散系数(PDI)的影响,获得了制备木薯淀粉纳米颗粒的最优条件:淀粉乳浓度20 mg/mL,微波超声波处理功率为24:500 W:W,微波超声波处理时间是50 min,料醇比1:8,淀粉溶液的滴加速率是20 mL/min,滴加淀粉溶液过程中微波超声波功率为24:300 W:W。通过傅里叶红外光谱、场发射扫描电子显微镜、X-射线衍射仪对木薯原淀粉和最优条件下合成的木薯淀粉纳米颗粒进行了表征。研究了淀粉纳米颗粒的溶解度、溶胀度、吸水率、吸油率等理化性质。结果表明,木薯淀粉纳米颗粒球形形貌较好,尺寸分布较均一。晶型由A型变为V型,相对结晶度明显降低。与木薯原淀粉相比,淀粉纳米颗粒的溶解度由0.9%提高到78.3%、溶胀度由4.166%提高到10.86%、吸油率提高了170%、12 h内的吸水率提高了3.1%,分散性实验表明木薯淀粉纳米颗粒在水溶液中的分散性较好。该淀粉纳米颗粒可用于食品色素、香料、调味料、维生素、油脂等产品中,应用价值较高。

Preparation and Characterization of Cassava Starch Nanoparticles with Radiation of Microwave and Ultrasonic

Cassava starch nanoparticles, Guangxi specialty resources cassava native starch as raw material, were prepared by precipitation method with the aid of microwave and ultrasound.The effects of starch milk concentration, volume ratio of starch solution to absolute ethanol, dropping rate of starch solution, the power of microwave ultrasonic, the time of microwave ultrasonic, the microwave ultrasonic power in the starch solution drop process on starch nanoparticle size and polydispersity index were investigated by dynamic light scattering technique.Therefore, the optimal conditions for the preparation of cassava starch nanoparticles were obtained:The starch milk concentration was 20 mg/mL, the power of microwave ultrasonic was 24:500 W:W, the time of microwave ultrasonic was 50 min, the feed-to-alcohol ratio was 1:8, the dropping rate of starch solution was 20 mL/min and the microwave ultrasonic power in the process of adding starch solution was 24:300 W:W.Fourier transform infrared spectroscopy, field emission scanning electron microscope, X-ray diffraction were used to characterize the cassava native starch and cassava starch nanoparticles. The physicochemical properties of starch nanoparticles such as solubility, swelling degree, water absorption and oil absorption were studied.The results showed that cassava starch nanoparticles had good spherical morphology and the size distribution was uniform.The crystal type of cassava starch nanoparticles changed from A type to V type, and the relative crystallinity decreased significantly.Compared with cassava native starch, the solubility of starch nanoparticles increased from 0.9% to 78.3%, the degree of swelling increased from 4.166% to 10.86%, the oil absorption rate increased by 170%, the water absorption rate increased by 3.1% within 12 hours, and the cassava starch nanoparticles had good dispersibility in aqueous solution.The starch nanoparticles had high application value which can be used in food pigments, spices, seasonings, vitamins, oils and other products.