Analysis of free amino acids in several wild seaweed species
CAO Zeng-mei, WANG Wei-wei, CHEN Juan, WANG Na, QU Yan-yan, LIANG Guang-jin
National Engineering and Technique Research and Development Center of Algae and Sea Cucumber of China, Provincial Key Laboratory of Genetic Improvement and Efficient Culture of Marine Algae of Shandong, Shandong Oriental Ocean Sci-tech Company Limited, Yantai 264003, China
Abstract: The comparative analysis of free amino acids (FAA) was conducted in Chlorophyta including sea lettuce(Ulva lactuca), Rhodophyta (Mazzaella japonica and Gelidium amansii)， and Phaeophyta (Sargassum pallidum) by high performance liquid chromatography (HPLC) to meet the development demand of wild seaweed resources and the diverse biological functions of FAA. The results showed that there were significant differences in FAA contents and compositions among the four species of wild seaweed, with the maximal FAA (8.50 mg/g) and essential amino acid (EAA, 0.78 mg/g) contents in M.japonica, followed by S.pallidum(7.45 and 0.69 mg/g, respectively) and G.amansii (6.84 and 0.52 mg/g, respectively) and the minimal in sea lettuce (4.45 and 0.34 mg/g, respectively). The maximal contents of histidine (His), alanine (Ala) and glutamic acid (Glu) were observed in sea lettuce, M.japonica and G.amansii, respectively, while Glu, aspartic acid (Asp) and Ala were the substantial amount of FAA in S.pallidum. The M. japonica had 89.37% of flavor amino acid in FAA and G.amansii had 89.71% of flavor amino acid in FAA, significantly higher than S.pallidum(77.13%)and sea lettuce(31.53%) did (P<0.05). There were significant differences in the composition of free EAA among the four species of wild seaweed, rich in valine (Val)in M.japonica, methionine (Met) and threonine (Thr). Leu, Val and Met were in S.pallidum, Met in G.amansii, Thr and Met in sea lettuce, and rich in lysine (Lys) in the four species of seaweed. However, no Val and phenylalanine (Phe) were detected in sea lettuce and no Phe was detected in G.amansii.
2018, Vol. 33 
