艾草精油Pickering乳液稳定性的研究

Study on the stability of Artemisia argyi essential oil Pickering emulsion

固体颗粒作为稳定剂包裹精油制备成Pickering乳液可以有效解决精油强挥发性的问题。为探究影响艾草精油Pickering乳液稳定的因素,以纤维素纳米晶作为稳定剂制备了艾草精油Pickering乳液,利用荧光显微镜、激光粒度分布仪和紫外分光光度计研究pH值、分散时间、超声时间等因素对乳液稳定性及乳液液滴粒径的影响,并通过测定精油的损失率分析艾草精油Pickering乳液的缓释效果。结果表明:乳液水相的pH值、分散时间和超声时间对艾草精油Pickering乳液的乳化稳定指数(ESI)和体积平均粒径(D_(4,3))有显著性影响(P<0.05);当水相pH值为3时,乳液的ESI最高,为(26365.14±1422.61)min,乳液的D_(4,3)最小,为(0.82±0.02)μm;分散时间增加到120 s时,乳液的ESI最高,为(9438.84±41.17)min,D_(4,3)最小,为(1.22±0.01)μm;同时,超声时间为20 min时,乳液的ESI最高,为(8920.54±509.61)min,乳液的D_(4,3)最小,为(1.29±0.06)μm。缓释性分析表明24 h时精油的损失率为8.17%,艾草精油Pickering乳液的损失率为1.72%,将艾草精油制备成Pickering乳液显著延缓艾草精油的释放(P<0.05),为开发绿色安全的植物源抑菌剂提供了参考。

The issue of volatility,chemical instability and water-insolubility of Artemisia argyi essential oil(AAEO)can be solved by preparing essential oil into Pickering emulsions(PEs).Usually,PEs are balanced out by solid particles that accumulate at the oil-water interface and reduce the system’s interfacial energy,as opposed to conventional emulsifiers.These solid particles are neither soluble in water nor soluble in the oil phase so that these amphiphilic particles will accumulate at the oil-water interface.Cellulose nanocrystals(CNCs)are considered to fit particles for oil-in-water PEs,and have a few significant qualities like high crystallinity,high aspect ratio,and excellent mechanical properties.AAEO as the oil phase and CNCs as the stabilizer were used to prepare the Artemisia argyi essential oil Pickering emulsion(AAEO-PEs).In this research,we are going center on finding more appropriate strategies to extend the stabilization time of emulsions for better application in food and other industries.The effects of pH value,dispersion time and ultrasonic time on the emulsifying stability index(ESI)and volumetric mean particle size(D_(4,3))of the emulsion were investigated using fluorescence microscopy,laser particle size distribution instrument,and UV spectrophotometer.In addition,the sustained release effect of AAEO-PEs was studied by measuring its loss rate.The results showed that as the pH value increased from 3 to 11,the AAEO-PEs stability decreased and then increased,and the droplet size increased and then decreased,in addition,when the pH value of the aqueous phase was 3,the highest ESI value of the emulsion was(26365.14±1422.61)min and the smallest D_(4,3) of the emulsion was(0.82±0.02)μm.When the dispersion time was increased to 120 s,the highest ESI value of the emulsion was(9438.84±41.17)min and the smallest D_(4,3) was(1.22±0.01)μm.Also,the ultrasonic time increased the AAEO stability,and the ESI increased from(2627.63±35.17)min to(8920.54±509.61)min when the sonication time was extended from 0 min to 20 min,and the minimum D_(4,3) of the emulsion was(1.29±0.06)μm.The slow release analysis showed that the loss of essential oil was 8.17%compared to 1.72%for AAEO-PEs at 24 h,which significantly delayed the release of essential oil by preparing it into Pickering emulsion(P<0.05).This study has a guiding significance for the development and application of Artemisia argyi essential oil and provides a reference for the development of green and safe plant-derived bacteriostatic agents.