微射流技术对食品大分子物质性质及结构的影响

Effect of Microfluidization Technology on Properties and Structure of Macromolecular Substances

摘要:

利用动态高压微射流（dynamic high-pressure microfluidization，DHPM）对纤维多糖（AX）、蛋白质（WP）、淀粉（PS）和果胶（PE）进行均质处理，通过分析处理前后大分子物质的粒径、扫描电镜图、X射线衍射图、紫外吸收光谱、傅里叶红外光谱以及表观黏度，研究DHPM对大分子物质基本性质和结构的影响。结果发现：经DHPM处理后4种大分子物质粒径均减小，平均粒径分别减小了79%、31%、68%、63%，大分子颗粒表面在剪切力作用下受到了不同程度的剪切和破碎，AX和PS的表观黏度增加，WP和PE则减少；X射线衍射、紫外吸收光谱及傅里叶红外光谱结果显示均质前后的特征峰及官能团未发生改变，而吸收峰的强度有不同程度的变化，样品部分吸收峰发生红移，AX、PS、PE的O—H氢键缔合伸缩振动特征吸收峰峰宽增加，WP二级结构α-螺旋消失，β-折叠含量减少，结晶度下降。可以看出，DHPM处理使4种大分子物质的性质及结构产生一定的改变。该研究为食品大分子物质的深度开发与资源利用提供了理论依据。

Abstract:

Dynamic high-pressure microfluidization (DHPM) were applied to homogenize cellulose polysaccharide (AX), protein (WP), starch (PS) and pectin (PE). The effect of DHPM on the basic properties and structure of macromolecular substances before and after treatment was analyzed by the measurements of particle size, scanning electron microscope, X-ray diffraction (XRD), ultraviolet (UV) absorption spectrum, Fourier transform infrared (FT-IR) spectrum, and apparent viscosity. The results showed that the average particle sizes of four macromolecules after DHPM treatment decreased by 79%, 31%, 68%, and 63%, respectively. The surface of macromolecular particles was sheared and broken to different degrees under the action of shear force. The apparent viscosity of AX and PS increased, while that of WP and PE decreased. The results of XRD, UV absorption and FT-IR spectra showed that there was no change in the characteristic peaks and functional groups before and after homogenization, however, the intensity of the absorption peak varies in different degrees and some absorption peaks were red-shifted. The peak width of stretching vibration characteristic absorption peak of O—H hydrogen bond in AX, PS and PE increased. The α-helix of WP secondary structure disappeared, and the β-sheet content and crystallinity decreased. DHPM treatment could change the properties and structure of the four macromolecules to some extent. This study could provide a theoretical basis for the in-depth development and resource utilization of food macromolecular substances.