In this study, the proximate composition and the amino and fatty acid profi les of shrimp Litopenaeus vannamei(prey) and wild and cultured cuttlefi sh Sepia pharaonis(the latter fed the prey) were determined and compared with FAO/WHO recommendations. The resulting scores for isoleucine, phenylalanine+tyrosine, histidine, lysine, threonine, and tryptophan in cultured cuttlefi sh were ≥150. The ratio of EAA(essential amino acids)/nonessential amino acids in cultured cuttlefi sh(0.82) was higher than in the wild form(0.80). All EAA amino acid scores for cultured cuttlefi sh were higher than their wild counterparts, except for histidine and tryptophan. Both groups of cuttlefi sh possessed similar saturated fatty acid content, with the cultured containing much more total(Σ) monounsaturated fatty acids, Σ n-6 polyunsaturated fatty acids(PUFA), and eicosapentaenoic acid(C20:5 n-3) but less Σ n-3 PUFA, arachidonic acid(C20:4 n-6), and docosahexaenoic acid(C22:6 n-3) than their wild counterparts. Therefore, the present results suggest that these cultured cuttlefi sh were better than the wild form for human health. Notably, these results also indicate that the nutritional composition of these cuttlefi sh might have been signifi cantly affected by diet.
We developed a species-specific PCR method to identify species among dehydrated products of 10 sea cucumber species.Ten reverse species-specific primers designed from the 16 S rRNA gene,in combination with one forward universal primer,generated PCR fragments of ca.270 bp length for each species.The specificity of the PCR assay was tested with DNA of samples of 21 sea cucumber species.Amplification was observed in specific species only.The species-specific PCR method we developed was successfully applied to authenticate species of commercial products of dehydrated sea cucumber,and was proven to be a useful,rapid,and low-cost technique to identify the origin of the sea cucumber product.
Fish maw(the dried swimbladders of fish) is ranked in the list of the four sea treasures in Chinese cuisine. Fish maw is mainly produced from croaker, which is the most highly priced. However, some of the fish maw being sold as croaker maw are in fact not from croaker, but from the Nile perch Lates niloticus. The present work determined and compared the proximate composition, amino acid and fatty acid composition of croaker Protonibea diacanthus maw and perch L. niloticus maw. The results indicated that both maws were high protein sources and low in fat content. The dominant amino acids in both maws were glycine, proline, glutamic acid, alanine and arginine. These amino acids constituted 66.2% and 66.4% of the total amino acids in P. diacanthus and L. niloticus, respectively. The ratio of FAA: TAA(functional amino acids: total amino acids) in both maws were 0.69. This is a good explanation for why fish maws have been widely utilized as a traditional tonic and remedy in Asia. Except valine and histidine, all the essential amino acid contents in P. diacanthus were higher than in L. niloticus. Moreover, croaker P. diacanthus maw contained more AA and DHA than perch L. niloticus maw, showing a higher ratio of n-3 / n-6, which is more desirable.
