THE DRESSING RATE AND NUTRITIONAL COMPOSITION OF MUSCLE IN SPOTTED STEED (HEMIBARBUS MACULATES)AND SKIN CARP (HEMIBARBU LABEO)

Hemibarbus maculates and H.labeo, as two kinds of important economic freshwater fish, are widely distributed over all the river systems except for the Xinjiang, Tibet and western plateau.Presently, researchers have carried out some research works concerning morphology, taxonomy, breeding and culture of Hemibarbus maculates and H.labeo, however, few reports about the dressing rate and nutritional composition of muscle were not found.Therefore, it is necessary to determine these data for enriching the fish nutrition data and providing theoretical foundation about feed development and culture promotion.In this study ,measurements on the dressing rate in whole body and analysis of nutritional composition of muscle in Hemibarbus maculates and H.labeo were made.Twenty-six pond-cultured samples were collected from the Bihu pond at Lishui town of Zhejiang Province in China in March, 2006 and the dressing rate in whole body and nutritional composition of muscle were determined using 13 samples.The fatty acids composition of and the composition of amino acids (AA)of muscles were examined with 10 individuals.The result showed that the dressing rate in the spotted steed and skin carp were 70.61%and 71.52 %respectively, thus there were not significant differences between them by t-test.Analysis results of the nutritional composition were :moisture of muscle was 78.35%, crude protein 18.41 %, crude lipid 2.46 %, ash 0.75 %in the spotted steed.In the skin carp,moisture of muscle was 78.51 %, crude protein 17.73 %, crude lipid 1.96 %, ash 1.69 %.The content of crude protein and crude lipid in the spotted steed were higher than those in the skin carp (p<0.05),whereas the ash content was lower (p <0.05).The result indicated that there was no significant difference in the content of moisture in both spotted steed and skin carp.There are 11 kinds of fatty acids found in themuscle of spotted steed and skin carp,of which 4 kinds of saturated fatty acid (SFA),7 kinds of unsaturated fatty acid (UFA)(including 4 kinds of monounsaturated fatty acid (MUFA)and 3 kinds of polyunsaturated fatty acid (PUFA)).Remarkably , Docosahexaenic Acid(DHA)content occupies 5.00 % and 14.32 % in the spotted and skin carp, respectively.The percentage of PUFA in the muscle fatty acids of spotted steed and skin carp were 19.50 % and 30.46 %, respectively.As for the MUFA, the content of C18∶1in the muscle of spotted steed and skin carp was the maximum (38.09 % and 25.31 %in percentage , respectively), while the content of C22:1 was the minimum (1.53 %and 3.18% in percentage, respectively).To provide scientific basis for evaluating protein quantity in fish muscle to guide the utilization of protein resources ,AA grade point to the fish muscle was also examined.By the nutritional evaluation for the AA in muscle to human needs , the total content of AA in the muscle of spotted steed and skin carp were 63.07 %and 67.63% respectively.As to the delicious AA, the contents were 25.96 %and 26.30 %, respectively.As for the amino acids score (AAS), the first limited AA was valine and second limited AA were methlonine and cystine in both Hemibarbus maculates and H.labeo;the first limited amino acids were methlonine and cystine, second limited AA was valine based on chemical score (CS). From the above analysis and evaluation ,we concluded that itwas necessary to spread spotted steed and skin carp in Zhejiang Province due to their economic value and more nutrition as well as health consideration.