Abstract: Due to the instability, irritating odor and non-electrospinning of Alli, its application in the food packaging industry has been limited to a certain extent. In this paper, biodegradable biobase is used as a film-forming material loaded with Alli inclusion, to improve the defects of Alli and enhance the value of Alli utilization. Currently, the preparation of biodegradable antimicrobial nanofiber membranes has become an important research direction in the food packaging industry. 
Alli has a spectral antibacterial effect and cyclodextrin (β-CD) has a hydrophobic cavity structure and is non-toxic. Alli/β-CD-IC was obtained by wrapping Alli molecules in β-CD molecules by rotary evaporation. Alli/β-CD-IC (1:3) with mass fractions of 2%, 4% and 6% were added to the PUL/PVA hybrid spinning solution, and electrostatic spinning was utilized to obtain PUL/PVA @Alli/β-CD-IC nanofiber membranes under a voltage 20 kV, flow rate of 0.4 mL/h, receiving distance of 13 cm, temperature of 23°C, and relative humidity of 38%.
Analyzing the scanning electron microscope images and observing the Alli/β-CD-IC images all showed irregular surfaces, which were different from the morphology presented by the pure β-CD, and the original morphology was significantly changed. In the PUL/PVA (7:3) mixture, there are smaller beads in the PUL/PVA @Alli/β-CD-IC nanofiber membrane, and the nanofiber membrane prepared by adding Alli/β-CD-IC has better morphology and uniform fiber diameter, which indicates that PUL/PVA@Alli/β-CD-IC nanofibers have a filamentous and continuous fiber structure. The analysis of infrared spectra and the comparison of PUL/PVA hybrid nanofiber membranes with PUL and PVA as-received fiber membranes showed that the O-H bond vibration peak was shifted, and there was intermolecular interaction between PVA and PUL. The spectra of the characteristic peaks of PUL/PVA nanofibrous membranes loaded with Alli/β-CD-IC were like those of PUL/PVA nanofibrous membranes, while the Alli/β-CD-IC characteristic peak disappeared. The XRD results showed that the peaks of PUL/PVA nanofiber membranes were shifted to the right, indicating that the close interaction between PUL and PVA molecules hindered the formation of a crystal structure, and the formation of hydrogen bonds through the interaction of PUL and PVA polymers resulted in the intermolecular interaction force that would act differently with different proportions of PVA. The peaks of the nanofiber membranes loaded with Alli/β-CD-IC were all shifted to the right and did not show any special peaks like those of Alli/β-CD-IC and sharp peaks of the crystal structure, suggesting intermolecular interactions that hindered the formation of crystals and led to an amorphous structure. The number of colonies on the solid medium was significantly reduced when 0.8 g of Alli/β-CD-IC was added in comparison, and the inhibition rate could reach 99.82±0.17%; the PUL/PVA @Alli/β-CD-IC nanofiber membrane prepared with loaded Alli/β-CD-IC had a significant inhibitory property on the growth of E. coli, and the inhibition rate could reach 99.91±0.07%. The experimental results showed that allicin and its inclusion complexes had significant growth inhibition effect on fungi.
Expanding the field of food packaging to prepare green and degradable antimicrobial nanomaterials, PUL and PVA were used as spinning substrates, loaded with Alli/β-CD-IC, and PUL/PVA @Alli/β-CD-IC nanofibrous membranes were prepared under certain spinning conditions, and the results are shown below. In this paper, in order to improve the Alli instability and unpleasant odor, Alli and β-CD were encapsulated with a mass ratio of 1:3, and the encapsulation efficiency reached 98.6%. The formed Alli/β-CD-IC still had a significant antimicrobial effect, and the inhibition rate could reach 99.82%. PUL and PVA were selected as the substrate membranes and loaded with Alli/β-CD-IC to improve the utilization of Alli/β-CD-IC, and the experiments proved that the degradable substrate membranes were loaded with Alli/β-CD-IC, and PUL/PVA @Alli/β-CD-IC nanofibrous membranes were successfully prepared to improve the application range of Alli. Different ratios of PUL/PVA @Alli/β-CD-IC nanofiber membranes inhibited the growth of E. coli with an antimicrobial efficiency of 99.91%. The degradable nanofiber membranes not only changed the defects of antimicrobial essential oils that were unstable and difficult to load, but also provided a new way of thinking about the application of Alli in different fields.

Key words: electrostatic spinning, allicin, cyclodextrin, nanofiber membrane,  , inclusion, antimicrobial properties

摘要： 针对大蒜素（Alli）不稳定的缺陷，采用环糊精（β-CD）包合技术，将Alli有效包合到β-CD空腔中；通过静电纺丝技术，将包合后的Alli负载到以普鲁兰（PUL）和聚乙烯醇（PVA）为纺丝基材的纳米纤维中，制备出具有抗菌活性的PUL/PVA@Alli/β-CD-IC纳米纤维膜。通过扫描电镜观察该纳米纤维膜的形貌，采用傅里叶红外光谱和X射线衍射分析物质相互作用和结晶性能，利用紫外可见分光光度计测试包封率，并依据平板计数实验测得试样抑菌率。结果表明：PUL/PVA@Alli/β-CD-IC纳米纤维膜的纤维连续且平均直径为(414.45±12.09) nm；Alli被有效包合于β-CD空腔中，且 PUL、PVA与Alli/β-CD-IC之间存在氢键作用；在Alli与β-CD质量比1∶3时，Alli/β-CD-IC可获得最高包封率（98.6%），PUL/PVA @Alli/β-CD-IC纳米纤维膜对大肠杆菌的抑菌率可达(99.91±0.07)%。因此，PUL/PVA@Alli/β-CD-IC纳米纤维膜具有优异的抗菌性能，其在活性食品包装材料领域有较大的应用潜能。

关键词: 静电纺, 大蒜素, 环糊精, 纳米纤维膜, 包合物, 抗菌性