Among the most widespread starch derivatives, etherified and esterified starches play an important role. These derivatives are generally prepared by using thermal energy and conventional solvents. This review summarizes the recent advancements in the etherification and esterification of starch in unconventional media, i.e. ionic liquids or supercritical CO₂, and by employing unconventional technologies, i.e. microwaves, ultrasounds or ball-milling. The present contribution aims to provide an overview to help researchers seeking an alternative medium or technology to functionalize starch. The green aspects of unconventional approaches are presented and the physical-chemical properties of modified starches obtained by these approaches are also described. Whenever possible, the advantages and disadvantages of each system are discussed. Finally, even if it is not always mentioned in the publications, the use of these experimental conditions probably leads to a partial degradation of the starch molecular structure.

中文翻译：

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淀粉醚化和酯化的非常规介质和技术

在最广泛使用的淀粉衍生物中，醚化和酯化淀粉起着重要作用。这些衍生物通常通过使用热能和常规溶剂来制备。本文总结在醚化和在非常规媒体淀粉酯化的最新进展，即离子液体或超临界二氧化碳₂，并且通过采用非常规的技术，即微波，超声波或球磨。本文稿旨在提供概述，以帮助研究人员寻找替代性的媒介或技术来使淀粉功能化。介绍了非常规方法的绿色方面，还描述了通过这些方法获得的改性淀粉的物理化学性质。尽可能讨论每个系统的优缺点。最后，即使在出版物中未经常提及，使用这些实验条件也可能导致淀粉分子结构的部分降解。