Abstract

The objective of this work was to evaluate the effects of extrusion pretreatment on the efficiency of lipid extraction and the quality of lipid extracted from the microalga Nannochloropsis oceanica. Five processing parameters of extrusion pretreatment using a twin-screw extruder were studied: die configuration, distance from the internal surface of the die to the end of the screw (δ), temperature, screw rotation speed, and the water content of biomass. The results showed that die configuration, δ, and the water content of the biomass were vital factors affecting lipid extraction efficiency. After the pretreatment of extrusion, the extraction time was shortened from 10 h to 20 min, and the amount of solvent used was reduced to one-third of that without pretreatment. The content of polyunsaturated fatty acid (PUFA) in crude lipid increased by over 30 percent of those components without pretreatment, especially for eicosapentaenoic acid (EPA), which increased by 37.45%. In addition, the unsaponifiable content and acid value of the crude lipid extracted from the extruded microalga decreased significantly, which would facilitate further refining processes.

中文翻译：

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双螺杆挤出机挤压预处理后从楠绿藻生物质中提取脂质：工艺参数的优化和脂质质量的比较

摘要

这项工作的目的是评估挤压预处理对微藻Nannochloropsis oceanica的脂质提取效率和脂质提取质量的影响。研究了使用双螺杆挤出机进行挤出预处理的五个工艺参数：模头配置，从模头内表面到螺杆末端的距离（δ），温度，螺杆转速和生物质的水分含量。结果表明，模具结构δ，生物质中的水分是影响脂质提取效率的重要因素。挤压的预处理后，萃取时间从10小时缩短到20分钟，溶剂用量减少到未经预处理的三分之一。未经预处理的粗脂肪中多不饱和脂肪酸（PUFA）的含量增加了30％以上，尤其是二十碳五烯酸（EPA）则增加了37.45％。另外，从挤压微藻中提取的粗脂质的不皂化物含量和酸值显着降低，这将有助于进一步的精制过程。