Comparative Analysis of Free Amino Acids in Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis

The contents of free amino acids(FAAs) in Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis was analyzed by using the automatic amino acid analyzer in this study. The results show that the sequence from the highest to the lowest in total amount of FAAs is Parapenaeopsis hardwickii, Penaeus vannamei and Macrobrachium nipponensis. SPSS(19.0) results indicate that except for Cys, Lys and Thr, FAAs in these three shrimps are significant different (p<0.05), and all of them have a high concentration of Arg, Gly and Pro and a low concentration of Asp and Cys. The content of Gly in shrimp is higher than that of crab and oyster. Both Arg and Gly significantly contribute to the taste of the three shrimps, Glu and Pro play an important role in the flavor of Parapenaeopsis hardwickii and Penaeus vannamei, while not as significant as in the taste of Macrobrachium nipponensis. Composition modes of FAAs which make major contributions to flavor in marine shrimps, Parapenaeopsis hardwickii and Penaeus vannamei, are similar, but different from freshwater shrimp, Macrobrachium nipponensis.