Studies On The Industrialization Technology Of High Quality Antarctic Krill

Nowadays Antarctic krill oil in the market was mainly prepared by organic solvent extraction.Differences of the materials, solvent character, and extracting conditions maight affect the oil quality and security seriously, such as high.levels of free fatty acids, cholesterol and residual solvent present. Most Antarctic krill oil was appeared as dark red, semi-fluid nature and opaque. This study aimed at developing an industrialization technology of high quality Antarctic krill oil,by optimizing the extraction conditions, removal of hazard factors and the pilot production. In addition, the stability of Antarctic krill oil was evaluated in this study. Main conclusions of the study were as follows:1) The influences of different raw materials, solvent systems and supercritical carbon dioxide fluid extraction technology on the recovery rate and lipid composition of Antarctic krill oil were studied.95%ethanol was used as extraction solvent and the optimal extracting condition was obtained by using response surface method:the solid to liquid ratio was1:12, and the temperature was45℃for6hours.Under these conditions, the yield of Antarctic krill oil was16.90%, the phospholipids content was35.59±2.69%(EPA26.86%, DHA14.27%).2) The removal technology of risk factors in Antarctic krill oil was studied.The removal of free fatty acids and retention of phospholipids and astaxanthin by different deacidifying methods were compared, including traditional alkali treatment, active material adsorption and supercritical carbon dioxide extraction. The results showed that active material adsorption had better removal effect of free fatty acids in the Antarctic krill oil with less loss of phospholipids and astaxanthin. On this basis, the optimal conditions of active material adsorption were obtained:20%chitosan was added in and the stirring adsorption was kept under40℃for60min, the removal rate of free fatty acid was42.83%.The removal rate of cholesterol in the Antarctic krill oil by different methods was compared, including active material adsorption, embedding and supercritical carbon dioxide fluid extraction. The results showed that:β-cyclodextrin (β-CD) has a specific structure that can accommodate a cholesterol molecule forming cholesterol/β-CD complex which neither soluble in water or oils. This method could effectively remove cholesterol from Antarctic krill oil. The optimized conditions of removal total cholesterol in Antarctic krill oil were obtained by orthogonal experiments:10%β-cyclodextrin was added in and the stirring adsorption was kept under40℃for30min, the removal rate of cholesterol was47.63%.The removal rate of solid particles and residual solvent in Antarctic krill oil by membrane separation and molecular distillation technology was studied. The results showed that:ceramic membrane filtration technology and molecular distillation technology could effectively remove various impurities in Antarctic krill oil, improve transparency and liquidity which enhanced the quality of the Antarctic krill oil.3) The pilot production of Antarctic krill oil was studied. On the basis of the extraction and removal technologies of hazardous factors, high quality Antarctic krill oil industrial process by pilot production was established. The research results showed that Antarctic krill oil by the pilot production was transparency, liquidity and contains50%phospholipids including more than95%PC content,40%DHA and EPA content.4) The stability of Antarctic krill oil was studied. Adding different antioxidants under different conditions researched the quality variation of Antarctic krill oil and predicted the shelf life of Antarctic krill oil with peroxide value (POV) as evaluation. The results showed that adding composite antioxidant, storing at4℃and filling the nitrogen could improve the stability of Antarctic krill oil, and the shelf life of krill oil could extend to1year.