Study On The Meat Quality Characteristics Of South Bay Bighead Carp

The ratio of flesh, eating quality, nutrition compounds, heavy metals, fatty acidcomposition and volatile flavor substances of122±0.5years old, health and normaldevelopment South Bay bighead carps that were randomly selected in the South Bay Lakewere systematically detected with automatic amino acid analyzer, flame atomic absorptionspectrophotometer, GC-MS, and12pond bighead carps were also detected as a control. Theresults showed that:1. Rate of the meat: South Bay bighead carp was higher than fish meat. The beforeslaughter average weight of2years old South Bay bighead carp was2.94Kg, length was67cm, the bones average weight was178g, the changes of ratio of flesh in the scope of70.94%-75.65%, and the average was74.03±1.76％.And before slaughter average weight ofthe control was2.91Kg, length was65cm, the bones average weight was150g,the averageratio of flesh was72.94±1.26％.From these data we can see: South Bay bighead carp weresignificantly higher than the control in before slaughter weight, length, and rate of the meat.2. Eating quality: The pH1, pH24, water holding capacity and tenderness of South Baybighead carp were respectively6.76,6.71,3.79%and0.49Kgf, and they were respectivelyhigher0.11,0.11,0.64%and0.08Kgf than that of the control. These showed that the meat ofSouth Bay bighead carp had good nutrition quality.3. Nutrition compounds: the contents of crude protein, crude ash and crude fat of SouthBay bighead carp was respectively18.35%,1.83%and1.06%,among them, crude protein andcrude fat were significantly (P <0.05) higher than that in the pond control. South Bay bigheadcarp was rich in mineral content. Mineral content of South Bay bighead carp weresignificantly higher than the control but calcium and manganese, especially potassium, zinc,phosphorus and selenium, respectively, higher11.24mg/100g,1.68mg/100g,74.67mg/100g and0.08mg/kg than that of control. VA and VB were significantly higher4.84mg/kg and7μg/100g respectively than that of control. However, the VB2slightly lowerthan that of control. The total amino acids of South Bay bighead carp was181.7g/Kg, amongthem, the essential amino acids was71.3g/Kg,and non-essential amino acids was110.4g/Kg,they were respectively higher15.6%and18.1%than that of control. The flavoramino acids(the sum of ASP、GLU、SER、GLY、ALA and PRO) of South Bay bighead carp,which was89.6g/Kg, was higher21.6%than that of control, among them, glutamate was36.2g/Kg, which was higher31.2%than that of control. Whether AAS or CS, the score of amino acid of South Bay bighead carp were higher than the control.4. Heavy metal residues: Lead, arsenic, and mercury content of South Bay bighead carpwere all subject to the provisions of NY5073-2006.5. Fatty acid composition:23kinds of fatty acids were detected from the South Baybighead carp, including6kinds of saturated fatty acids（27.9%）,6kinds of monounsaturatedfatty acids（24.3%）,and11kinds of polyunsaturated fatty acids（47.8%）.The content ofunsaturated fatty acids was about2.6times of the saturated fatty acids. Compared to thecontrol, polyunsaturated fatty acid was higher1.69%, in which C20:3（n-6） and C20:5（n-6）were respectively higher1.24%and6.4%.6. Volatile flavor compounds:41kinds of volatile flavor compounds were detected fromthe South Bay bighead carp, among them, aldehydes15(49.15%), Alcohols5(5.03%),ketones3(2.54%), hydrocarbon compounds8(10.3%), acids2(3.42%), esters3(9.63%),heterocyclic compounds5(9.34%). According to the ratio of relative content of eachcomponent and the threshold, we can conclude that2,4-decadienal (fried greasy), ethylacetate (floral),1-octen-3-ol (smell of the soil),2-ethyl furan (malt flavor), hexanal (grassflavor), twelve aldehyde (citrus flavor) had main contribution to the flavor of South Baybighead carp.In summary, South Bay bighead carp had the following quality characteristicscompared with the pond control: a high Rate of the meat, nutrient-rich, high eating quality,good flavor, heavy metal residues low.