微波协同酶法处理葛根粉对其结构及性质的影响

Effects of Microwave⁃Enzymatic Method on Structure and Properties of Pueraria lobata Powder

为研究微波协同普鲁兰酶酶解法处理葛根粉对其结构及性质的影响,采用微波法对淀粉乳浓度分别为10%、15%的葛根粉-水体系进行为期60 s和120 s的微波辐照以及100 U/g的普鲁兰酶酶解8 h,冷冻干燥后获得经过复合改性的葛根粉样品(compound modified Pueraria lobata,CM-PL),样品名称分别记为CM-PL10-1、CM-PL10-2、CM-PL15-1、CM-PL15-2;通过显微镜对改性葛根粉的微观结构进行表征,同时测定其颗粒粒径、吸水率、透光率、溶解度、膨胀势以及流变行为等指标。结果表明,随着葛根粉-水体系中葛根粉浓度的增加,改性葛根粉的颗粒表面出现凹陷和裂纹;与原葛根粉相比,改性葛根粉的颗粒粒径、吸水率和透光率明显增加。且当温度达到90℃时,改性葛根粉的溶解度与膨胀势分别有不同的增长趋势;微波-酶法并没有改变葛根粉样品的流体类型,所有样品均呈现出假塑性流体特征及剪切稀化现象。

The study examined the effect of combined microwave and pullulanase enzymatic treatment on the structure and properties of Pueraria lobata powder.Microwave irradiation was carried out for 60 s and 120 s on the puerarin powder-water system with a mass ratio of 10%and 15%,and enzymatic hydrolysis with 100 U/g pullulanase for 8 h.After freeze-drying,compound modified P.lobata(CM-PL)samples were obtained and named CM-PL10-1,CM-PL10-2,CM-PL15-1,and CM-PL15-2.The microstructure of the modified P.lobata powder was characterized using a microscope,and various parameters including the particle size,water absorption,transparency,solubility,swelling potential,and rheological behavior were measured.The results showed that with the increase in the concentration of P.lobata powder in the powdery water system,sag and crack ap-peared on the surface of the modified P.lobata powder.Compared with the original P.lobata powder,the par-ticle size,water absorption,and light transmittance of the modified P.lobata powder were significantly in-creased.When the temperature reached 90℃,the solubility and expansion potential of the modified P.lobata powder showed different growth trends.The microwave-enzyme method did not alter the fluid type of the P.lo-bata powder samples.Therefore all samples exhibited pseudoplastic fluid characteristics and shear thinning phenomenon.