纳米淀粉的制备、性质及应用的研究进展

Research Progress in Preparation,Properties and Application of Nano-starch

植物淀粉是一种无毒、高产量、低敏性、可降解再生的优良原料,但是较大的颗粒和非牛顿流体等特性限制了淀粉的应用范围。随着纳米技术的兴起,纳米尺寸下的淀粉颗粒因具有比表面积大、羟基多等良好的理化特性而受到越来越多研究者的关注,其制备方法趋于多样化,应用也不再局限于传统的食品及饲料行业,在医药及其他工业领域均有广阔的应用前景。然而,已有的纳米淀粉制备方法存在各种不足。例如,最基础的水解法制得的纳米淀粉产量低,颗粒结构遭到破坏,粒度分布不均匀;常用的化学方法多采用有毒的化学试剂,且无法回收。针对已经存在的问题,越来越多的研究者尝试采用新的制备方法以减少对环境的污染,改善纳米淀粉的理化性质,扩大其应用范围。现多尝试用多种化学试剂与淀粉反应,通过化学试剂自身的官能团与淀粉发生反应,进行性质加成。有研究表明,天然玉米淀粉可与乙酸和乙酸酐反应制备不同取代度的乙酰化淀粉,其可用于药物环丙沙星的递送载体,通过体外实验表征递送基质的潜力。实验表明,该反应制得的纳米颗粒尺寸均匀,并且包封效率明显提高。本文以“自上而下”和“自下而上”的思路分析对比了水解法、机械研磨法、超声波法、高压均质法、反应挤出法、辐照法和碱冷冻法、化学沉淀法、乳化交联法、静电喷雾法、自组装法和辐照交联法等淀粉纳米化制备方法,并对制得的纳米淀粉的形态结构、结晶度、热力学和流变学性质进行了分析,并对其性质和应用进行了相应的归类。已有文献表明,纳米淀粉已在包装、医药、造纸、污水处理等方面有所应用,未来可以充分利用纳米淀粉颗粒表面的众多羟基开展修饰改性和淀粉的生物相容性研究,得到更高附加值的纳米淀粉产品。

Plant starch is an excellent raw material for non-toxic,high-yield,low-sensitivity,degradable regeneration,but the characteristics of larger particles and non-Newtonian fluid limit the application range of starch.With the rise of nanotechnology,starch particles with nanometer size have large specific surface area,and good physical and chemical properties such as polyhydroxyl are attract more and more researchers’attention.The preparation methods tend to be diversified,and applications are no longer limited.The traditional food and feed industry has broad application prospects in the pharmaceutical and other industrial fields.However,existing methods for preparing nano-starch have various drawbacks.For example,the nano-starch prepared by the most basic hydrolysis method has low yield,damaged particle structure,and uneven particle size distribution;commonly used chemical methods use toxic chemical reagents and cannot be recovered.In response to existing problems,more and more researchers are trying to adopt new preparation methods to reduce environmental pollution,improve the physical and chemical properties of nano-starch,and expand its application range.At present,many attempts have been made to react with starch by various chemical reagents,and the functional group of the chemical reagent reacts with the starch to carry out a property addition.Studies have shown that natural corn starch reacts with acetic acid and acetic anhydride to prepare acetylated starch with different degrees of substitution for the delivery of the drug ciprofloxacin,and the potential for delivery of the matrix is characterized by in vitro experiments.Experiments show that the nanoparticles prepared by the reaction are uniform in size and the encapsulation efficiency is significantly improved.This paper analyzes and compares the hydrolysis method,mechanical grinding method,ultrasonic method,high pressure homogenization method,reaction extrusion method,irradiation method and alkali freezing method,chemical precipitation with the ideas of“top-down”and“bottom-up”.Starch nanofabrication preparation methods such as emulsification cross-linking method,electrostatic spray method,self-assembly method and irradiation cross-linking method,and the morphology,crystallinity,thermodynamics and rheological properties of the prepared nano-starch are analyzed.The literature shows that nano-starch has been applied in packaging,medicine,papermaking,sewage treatment,etc.In the future,it can make full use of the many hydroxyl groups on the surface of nano-starch particles to carry out modification and biocompatibility of starch,and obtain higher added value.