Effect of different thawing methods on lipid quality of Antarctic krill (Euphausia superba)

In the present study,the effects of different thawing methods( natural thawing,low- temperature thawing,still water thawing,microwave thawing) on lipid quality changes of Antarctic krill( Euphausia superba) were carried out by analyzing the content of triglyceride,total cholesterol,phospholipids,free fatty acids,peroxide value,anisidine value,astaxanthin content and total fatty acid composition,combined with radar chart analytical method. The results showed that the thawing time taken by natural thawing,low- temperature thawing,still water thawing,microwave thawing was 210,450,90 and 5 min respectively.And the lipid qualities of the krill exhibited differences after being treated by different thawing methods,while the contents of free fatty acids and astaxanthin in the krill showed significant differences.The contents of free fatty acids were between 20.8% ~23.0% and astaxanthin were 391.7~429.9 μg / g.So,the contents of free fatty acids and astaxanthin would be the fast evaluation indexes for evaluating the lipid quality changes of the krill during the thawing process. The results of radar chart analysis showed that the evaluation results of thawing methods were ranked as still water thawing > low- temperature thawing > microwave thawing >natural thawing,from the aspect of the development and utilization of lipids. Considering the factor of product quality,thawing time and energy comsumption,still water thawing should be firstly chosen when extracting the krill oil using the frozen krill material during the process of land- based production.