多个条斑紫菜品系采收期内脂肪酸组成、含量的变化分析

The variation in fatty acids composition and content of ten Pyropia yezoensis cultivars during different harvest time periods

为探讨条斑紫菜不同栽培品系、不同采收期脂肪酸组成及含量的变化,本实验对10个栽培品系进行了跟踪测定分析,结果显示：条斑紫菜的脂肪酸组成稳定,与品系、采收期内季节性变化无关,但含量存在明显的差异。各品系的3个采收期的饱和脂肪酸（16∶0为主,包括13∶0、16∶0、18∶0）的相对含量约为20%;不饱和脂肪酸（以EPA为主,包括18∶1 n-9、18∶2 n-6、18∶3 n-3、20∶1 n-9、20∶2 n-7、20∶3 n-7、20∶4 n-6（AA）、20∶5 n-3（EPA））的相对含量为70%左右。在温度最低2月份的采收样品中,总脂肪酸和EPA含量最高,显示低温有利于条斑紫菜脂肪酸尤其是EPA的积累。另外,条斑紫菜富含以EPA为主的不饱和脂肪酸,在整个采收期内,样品中的n-6/n-3比值为4.9～7.7,符合WHO/FAO膳食推荐值。

Ten cultivated strains of Pyropia yezoensis were studied in this research in order to identify the effects of the strain difference and the harvesting time difference on the fatty acid composition and content of P.yezoensis. The results showed that the fatty acid composition of these ten P.yezonsis samples was not affected;however,the content of each fatty acid was affected and the difference among ten samples was significant.The saturated fatty acids （SFAs）were mainly composed of 13∶0,16∶0,18∶0 with 16∶0 as the highest component（about 20%）.The unsaturated fatty acids（UFAs）included 18∶1 n-9,18∶2 n-6,18∶3 n-3,20∶1 n-9,20∶2 n-7,20∶3 n-7,20∶4 n-6（AA）,20∶5 n-3（EPA）and the major componet was EPA（about 50%）.Samples harvested during the lowest water temperature period（February）contained the highest total fatty acids and EPA concentration;the result indicates that the low water temperature has advantages in accumulating fatty acids especially UFAs of P.yezoenis.P.yezoensis is rich in UFAs（especially EPA）.The n-6/n-3 ratios ranged from 4.9 to 7.7 during the whole study period,and this range is consistent with the recommended diet ratio of WHO/FAO.