国际纺织导报

该研究致力于深入分析牛角瓜纤维在提取过程中干燥步骤引起的纤维结构变化，及其对纤维抗大肠埃希菌效能的影响。作为一种具有显著中空结构的天然纤维，牛角瓜纤维在经过干燥处理后，其特有的物理特性可能会发生改变，从而对其抗菌性能产生影响。本研究采用不同干燥技术（包括微波、红外加热和多时段的自然风干）对牛角瓜果实进行处理，以获取不同干燥水平的纤维样本。对这些样本的抗大肠埃希菌性能进行了评估。同时，通过激光显微镜对纤维结构进行了观察。红外光谱和拉曼光谱分析则用于表征样本的含水量。结果表明，经过1个月自然风干的牛角瓜纤维对大肠埃希菌的抑菌率超过99%。纤维结构的变化主要表现为纤维壁的内凹，这与纤维的脱水程度密切相关。风干1个月且含水量较高的纤维凹陷比例为10%，而风干6个月且含水量较低的纤维凹陷比例达到80%，说明纤维的内凹程度随着失水量的增加而提高。这种凹陷结构有利于大肠埃希菌的生长，因为这些凹槽在纤维表面形成了细菌附着的微环境，从而在物理上促进了细菌的增长。因此，含水量高且几乎无凹陷结构的牛角瓜纤维能有效抑制大肠埃希菌的生长。干燥方法影响纤维的含水量，进而导致其微观结构的变化，并最终影响纤维抗菌性能。

This study is dedicated to a thorough analysis of the structural changes in Calotropis gigantea fibers during the drying step of the fiber extraction process and its specific impact on the antibacterial efficacy against Escherichia coli.As a natural fiber with a distinctive hollow structure,Calotropis gigantea fibers may undergo changes in their unique physical properties after drying treatment,thereby affecting their antibacterial performance.This research employed four different drying techniques(including microwave,infrared heating,and multi-period natural air drying)to process Calotropis gigantea fruits,obtaining fiber samples with various levels of dryness.The antibacterial performance of these samples against Escherichia coli was evaluated.Simultaneously,the fiber structure was observed using a laser microscope,while infrared spectroscopy and Raman spectroscopy analysis were used to characterize the water content of the samples.The results indicate that Calotropis gigantea fibers air-dried for one month exhibited an antibacterial capability of over 99% against Escherichia coli.The main change in fiber structure was the indentation of the fiber wall,closely related to the degree of dehydration.For instance,fibers air-dried for one month with a higher water content had a 10%indentation ratio,while those air-dried for six months with lower water content reached a 80%indentation ratio,showing that the degree of indentation increases with dehydration.This indented structure benefits the growth of Escherichia coli,as these indentations create microenvironments for bacterial attachment on the fiber surface,thereby physically promoting bacterial growth.Therefore,Calotropis gigantea fibers with high water content and almost no indentation effectively inhibits the growth of Escherichia coli.The drying method affects the water content of the fibers,which in turn leads to changes in the microstructure and ultimately impacts their antibacterial properties.