In this study the rheological properties of aqueous suspensions of three microalgae species, Nannochloropsis gaditana, Scenedesmus almeriensis and Spirulina platensis, were investigated as a function of solids content, and related to their composition and microstructure. In addition, the impact of ultrasound processing on their structuring ability was also studied. The less rigid character of the Spirulina platensis cell walls (with very low carbohydrate contents) and the presence of extracellular components promoted cell-cell interactions, yielding suspensions which showed a shear thinning behaviour at lower concentrations than Nannochloropsis gaditana and Scenedesmus almeriensis. It is noteworthy that the three species showed different viscoelastic properties at 25 wt.% total solids. Spirulina platensis suspensions showed a more elastic behaviour and lower frequency dependence, characteristic of weak gels, whilst Nannochloropsis gaditana and Scenedesmus almeriensis behaved more like viscous liquids. The ultrasound treatment did not affect the cell wall integrity, but it promoted the release of intracellular components (some of which could have been partially degraded) and disrupted physical interparticle interactions in Nannochloropsis gaditana and Scenedesmus almeriensis. This has an impact on the rheological properties, increasing the viscosity of Nannochloropsis gaditana suspensions, whilst the viscosity of Scenedesmus almeriensis suspensions was reduced. The outcomes of this work give insights into the exploitation of these microalgae species in soft materials for food, pharma and other technological applications.

在这项研究中，研究了三种微藻水悬浮液的流变学性质，它们是固体含量的函数，并与它们的组成和微结构有关，该微悬浮物的纳米藻，拟南芥，铝藻和螺旋藻都具有一定的流动性。此外，还研究了超声处理对其结构能力的影响。螺旋藻细胞壁的刚性较弱（碳水化合物含量非常低）和细胞外成分的存在促进了细胞间的相互作用，产生的悬浮液在比Nannochloropsis gaditana和Scenedesmus almeriensis更低的浓度下表现出剪切稀化行为。。值得注意的是，这三种物质在总固含量为25％（重量）时显示出不同的粘弹性。螺旋藻悬液表现出更强的弹性和较低的频率依赖性，是弱凝胶的特征，而Nannochloropsis gaditana和Scenedesmus almeriensis的表现更像粘性液体。超声处理不会影响细胞壁的完整性，但是会促进胞内成分的释放（其中一些成分可能会部分降解）并破坏Nannochloropsis gaditana和Scenedesmus almeriensis中的物理粒子间相互作用。这对流变性能有影响，增加了微拟球藻Gaditana旅游观光悬浮液，同时粘度栅藻almeriensis悬浮液减少。这项工作的成果使人们深入了解了在食品，制药和其他技术应用的软性材料中开发这些微藻类的方法。