超高压微射流对紫薯淀粉性质和结构的影响

Effects of Ultra-high Pressure Micro-fluidization on the Properties and Structure of Purple Sweet Potato Starch

以10%的紫薯淀粉溶液为原料,研究超高压微射流对紫薯淀粉的微观结构和性质的影响。结果表明,经超高压微射流处理后,紫薯淀粉吸水性、持油能力、冻融稳定性明显增强。与紫薯原淀粉RVA曲线相比,处理后的淀粉RVA曲线的走势和峰的数量基本不变,但是在峰顶值、谷底点以及曲线终点等关键点的粘度值有较大变化。随着超高压微射流处理压力的增大,紫薯淀粉糊化起始温度逐渐降低,且均低于原淀粉。在60 MPa时,紫薯淀粉糊化峰值温度最高,为78.82℃。偏光显微显示紫薯淀粉颗粒的偏光十字随着处理压力的增加逐渐模糊,经100 MPa处理后,多数淀粉颗粒偏光十字消失;红外吸收光谱和X射线衍射分析表明经超高压微射流处理后,紫薯淀粉结构发生一定程度的改变。

The effects of ultra-high pressure micro-fluidization on the structure and properties of purple sweet potato starch are analyzed with 10%purple sweet potato starch solution.The results show that the water absorption,oil holding ability and freeze-thaw stability of purple sweet potato starch are significantly enhanced after ultra-high pressure micro-fluidization treatment.Compared with the RVA curve of raw purple sweet potato starch,the trend and the number of peaks of the RVA curve of treated starch are basically unchanged,but the viscosity values of key points such as peak value,trough point and the end point of the curve are greatly changed.With the increase of ultra-high pressure micro-fluidization treatment pressure,the initial gelatinization temperature of purple sweet potato starch decreases gradually and is lower than that of the raw starch.At 60 MPa,the peak gelatinization temperature of purple sweet potato starch is the highest of 78.82℃.The polarizing microscope shows that the polarizing cross of purple sweet potato starch granules becomes blurred with the increase of treatment pressure,and the polarizing cross of most starch granules disappears after 100 MPa treatment;infrared absorption spectra and X-ray diffraction analysis resutts show that the structure of purple sweet potato starch changes to a certain extent after the treatment of ultra-high pressure micro-fluidization.