超声波-微波协同作用对玉米磷酸酯淀粉/秸秆纤维素可食膜机械性能的影响

利用超声波-微波协同技术制备玉米磷酸酯淀粉/秸秆纤维素（corn distarch phosphate/corn straw cellulose，CDP/CSC）可食膜，探讨超声波-微波处理条件对膜机械性能的影响。以抗拉强度（tensile strength，TS）和断裂伸长率（elongation at break，EAB）为指标，通过响应面分析优化得到最佳工艺条件为：超声波功率600 W、微波功率170 W、超声波-微波时间9 min。在此条件下可食膜的TS和EAB分别达到31.42 MPa和74.33%，与未经超声波-微波处理的膜相比分别提高62.29%和56.88%。通过扫描电子显微镜、傅里叶变换红外光谱分析和X射线衍射对可食膜进行结构观察和表征，经超声波-微波协同处理的CDP/CSC可食膜表面平整，结构致密，分子间作用力加强。超声波-微波联合作用可有效提高CDP/CSC可食膜的机械性能。

Effects of Ultrasonic-Microwave Treatment on Mechanical Properties of Corn Distarch Phosphate/Corn Straw Cellulose Films

Corn distarch phosphate/corn straw cellulose edible films were prepared using ultrasonic-microwave treatment. The effects of the combined treatment on mechanical properties of the films were studied. Based on tensile strength and elongation at break, the optimum conditions were obtained by response surface analysis as follows: ultrasonic power, 600 W; microwave power, 170 W; and radiation time, 9 min. Under these conditions, the tensile strength and elongation at break of edible films reached 31.42 MPa and 74.33%, respectively, which were increased by 62.29% and 56.88%, respectively, as compared with those of films without the use of ultrasonic-microwaves treatment. As observed and characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction (XRD), the edible films prepared by the combined treatment displayed smooth surface and dense structure, suggesting strong intermolecular forces. To conclude, the mechanical properties of corn distarch phosphate/corn straw cellulose edible films could be improved by ultrasonic-microwave treatment.