EPA/DHA磷脂是南极磷虾富含的特征功能脂质，极具开发价值，但受高活性内源酶影响，其在南极磷虾冻藏过程中仍易发生水解变化，导致南极磷虾脂质营养价值和加工价值下降，制约南极磷虾资源的高值化利用。目前，引起南极磷虾EPA/DHA磷脂水解的关键作用酶类型及其作用机制尚不明确。本项目拟首先采用磷脂组学分析手段阐明南极磷虾冻藏过程中EPA/DHA磷脂结构变化规律，结合磷脂水解酶酶活力变化速率与磷脂含量变化的相关性分析，确定引起EPA/DHA磷脂水解的关键作用酶；而后将关键作用酶进行纯化，研究其酶学特性；最后通过磷脂水解模拟试验，验证关键作用酶对EPA/DHA磷脂的水解作用，解析酶的水解位点和底物特异性，阐明酶的作用机制，揭示南极磷虾EPA/DHA磷脂的酶促水解机理。本项目研究将完善南极磷虾品质劣变机理的基础理论，并为南极磷虾加工贮藏方式的优化提供指导，对于推动南极磷虾产业发展具有重要意义。

Eicosapentaenoic acid/Docosahexaenoic acid-enriched phospholipids (EPA/DHA-enriched phospholipids), the key functional lipids rich in Antarctic krill (Euphausia superba), are of great value for development. Due to the high activity of endogenous enzyme in the krill, EPA/DHA-enriched phospholipids are prone to hydrolysis even under the frozen condition, which leads to the sharp decline in the nutritional value of the krill and has limited the high-efficient utilization of this polar biological resource. The type of the crucial endogenous enzyme responsible for the EPA/DHA-enriched phospholipids hydrolysis in the krill as well as its functionary mechanism still remain unclear and are urgent to be clarified. The present project is intended to a) define the structural changing regularity of the EPA/DHA-enriched phospholipids during frozen storage by the combination of the phospholipidomics technology and the multivariate statistical analysis method in order to provide auxiliary information for the identification of the crucial enzyme responsible for the EPA/DHA-enriched phospholipids hydrolysis, b) identify the crucial enzyme based on the correlation analysis between the changing rates of the enzyme activities of the phospholipids hydrolysis related enzymes and the changes of the phospholipids contents, c) purify the crucial enzyme and study the enzymatic properties to determine the specify conditions of the phospholipids hydrolysis simulation experiment, d) verify the hydrolytic action of the crucial enzyme on the EPA/DHA-enriched phospholipids and elucidate the hydrolysis sites and substrates specificity of the crucial enzyme through the simulation experiment in order to promulgate the enzymatic hydrolysis mechanism of the EPA/DHA-enriched phospholipids during frozen storage. This project could extend the basic theory of quality deterioration mechanism of the krill and provide scientific guidance for the optimization of processing and storage of the krill, which would be of great significance to promote the development of the whole industry.