Analysis and evaluation of muscular nutritional components in darkbarbel catfish Pelteoebagrus vachelli

The chemical composition,energy density and E/P were measured in fresh muscles of darkbarbel catfish Pelteoebagrus vachelli.There was higher crude protein content(15.87%) in darkbarbel catfish than those in yellow catfish Pelteoebagrus fulvidraco,oriental sheatfish Silurus ausotus,southern sheatfish Silurus meridionalis and Leiocassis longirostris,lower than that in large fin long barbel catfish Mystus macropterusand spotted long barbel catfish M.guttatus.The highest crude lipid content(7.55%),energy density and E/P and lowest moisture content(75.71%)were observed in the darkbarbel catfish.The higher crude ash content(1.11%) was found in darkbarbel catfish than that in yellow catfish,lower than that in large fin long barbel catfish and spotted long barbel catfish.Seventeen kinds of amino acids were determined in the muscles,including 7 essential amino acids(Thr,Val,Met,Phe,Ile,Leu and Lys),2 semi-essential amino acids(His,and Arg),and 8 nonessential amino acids(Asp,Glu,Ser,G1y,Ala,Tyr,Cys and Pro).The total amino acids(TAA),total essential amino acids(EAA),total semi-essential amino acids(HEAA),and total nonessential amino acids(NEAA) in dry samples from the farmed stocks were 64.31%,23.95%,6.39%,and 33.97%,respectively.The darkbarbel catfish had higher muscular TAA,EAA,HEAA and NEAA than oriental sheatfish and southern sheatfish did,and lower muscular TAA,EAA,HEAA and NEAA than yellow catfish,large fin long barbel catfish,spotted long barbel catfish and Leiocassis longirostris.The essential amino acids index(EAAI) was 53.92 mg/g and the constitutional rate of the essential amino acids(EAA) met the Food and Agriculture Organization of the United Nations(FAO)/Word Health Organization(WHO) Standard.According to nutrition evaluation,in the amino acids score(AAS) and chemical score(CS),the limited amino acids were Val,Met+Cys and Ile.The total content of 4 taste amino acids was 25.52%,among which Glu,Asp,Gly,Ala was 10.83%,6.22%,4.17%,and 4.30%,respectively,higher than that in oriental sheatfish and southern sheatfish,lower than that in yellow catfish,oriental sheatfish and southern sheatfish.There were 3 saturated fatty acids(SFA),2 mono-unsaturated fatty acids(MUFA) and 4 polyunsaturated fatty acids(PUFA) in the muscle,accounting for 26.53%,28.19%,36.89%in the total fatty aids,respectively.The amount of EPA+DHA,n-3 polyunsaturated fatty acids(n-3 PUFA),n-6 polyunsaturated fatty acids(n-6 PUFA) was 7.11%,7.11%,and 29.78%in fatty acids,respectively.The amount of EPA+ DHA in the muscle was higher than that in yellow catfish and oriental sheatfish.The amount of ω-6PUFA in the muscle was higher than that in yellow catfish and oriental sheatfish.In dry samples,Ca content in the muscle was lower than that in yellow catfish and southern sheatfish;P content was higher than that in yellow catfish and southern sheatfish.The present study revealed that darkbarbel catfish was a high energy fish and had the highest muscular linoleic acid content among the reported freshwater fish.