"863" Ecological Culture Model Of River Crab On Different Stocking Size Of Influence And Quality Evaluation

Eriocheir sinensis is not only a very delicious food,but also rich in amino acids,fatty acids and other nutrients beneficial to the human body.With the development of aquaculture technology,the ecological farming model can not only guarantee the quality of aquatic products,but also have a positive effect on the ecological environment.The eco-culture model is the trend of breeding Eriocheir sinensis.This experiment compares and analyzes the biological index of different specifications of crabs in the breeding process and the nutritional quality of pond crabs and purse seine under the "863" ecological farming mode in Yangcheng Lake area,for the cultivation of high quality Chinese velvet The ecological breeding model of crab provides a theoretical basis.1.The effect of stocking crabs with different specifications on biological index and water quality evaluationFrom the six aspects of body weight,muscle index,hepatopancreas index,gonadal index,total index of edible part and fatness,the number of clams was used as the time node to study the growth process of three different crabs.3 kinds of crabs of different specifications are divided into A#pond for weight 15-20g crab,B#pond for weight 10-15g crab,C#pond for weight 5-10g crab.Through research,it was found that the body weight of A#male crab was significantly higher than that of the other two ponds(P<0.05),and there was no significant difference in female crabs.From the muscle index,the muscle index of A#male crab was significantly lower than that of C#pond(P<0.05).There was no significant difference in female crabs.From the hepatopancreas index,the total edible index,the gonadal index,and the fullness of the liver,there were no significant differences between the three male and female crabs.From the perspective of economic efficiency,large-scale crabs have a great influence on the specifications of male crabs,which can effectively improve the efficiency.From the point of view of food,there is no significant difference in the fullness of the muscles of the male crabs.Large-scale crabs have no significant effect on the biological index of female crabs.It is not necessary to pursue large-scale crabs in actual female crab breeding.The main point of the "863" ecological breeding model of river crab is the regulation of water quality.Water quality data Ammonia nitrogen,nitrite nitrogen,total phosphorus,total nitrogen refer to DB32/T1705-2018 Taihu Lake Basin pond culture water discharge requirements to evaluate the monitoring data,water quality belongs to Class I and Class Ⅱ water standards,all within the safe range.2.Comparison of nutrient composition of "863" ecological pond crab and purse seine crab in Yangcheng Lake area(1)The results of biological index study showed that the hepatopancreas index of female crabs and male crabs were similar,but the female gland index of female crabs was higher than that of male crabs,which led to the higher index of edible parts of females than males.For female crabs.There were no significant differences between pond crabs and lake crabs.(2)The conventional biochemical components showed that the crude fat content of the female crabs in the two culture modes was significantly higher than that of the male crabs in the lake(P<0.05),and there was no significant difference in the water,ash and crude protein male and female crabs.(3)The results of fatty acid research indicated that 22 fatty acids were detected in the mixed samples of gonads and hepatopancreas of Eriocheir sinensis.Among them,PUFA detected 10 kinds of fatty acids,the most species,followed by SFA,8 detected,and MUFA detected 4.The MUFA content of the male crabs in the lake was significantly higher than that of the males in the ponds(P<0.05),and the MUFA in the females were also significantly higher than those in the ponds(P<0.05).The PUFA content of male crabs in ponds was significantly higher than that in lake males(P<0.05).The PUFA content of pond females was significantly higher than that of lake females(P<0.05).n-3PUF includes C18:3,C20:5(EPA),C22:6(DHA)three fatty acids.The content of n-3PUFA in pond male crab was significantly higher than that in lake male crab(P<0.05).The content of n-3PUFA in pond female crab was significantly higher than that in lake female crab(P<0.05).From the values of EPA+DHA and DHA/EPA,the male crabs in the pond were significantly higher than the male crabs in the lake(P<0.05),and the females in the ponds were significantly higher than the females in the lakes(P<0.05).The n-6 PUFA includes C18:2 and C20:4(ARA).The content of n-6 PUFA in male and female crabs was similar in the two culture models(P(?)0.05).(4)The results of amino acid research showed that the content of lys in pond male crab was significantly higher than that in lake male crab(P<0.05).In the NEAA,the pro content of male crabs in the lake was significantly higher than that in the pond males(P<0.05).The content of EAA,NEAA and TAA in pond-raised female crabs was slightly higher than that in lake-raised female crabs.The lys content of EAA male crab was significantly higher than that of lake male crab.The met content of pond female crab was significantly higher than that of lake female crab.In general,the content and type of nutrients of pond crabs under the"863"ecological farming mode in Yangcheng Lake area is better than that of lake crabs.3.Comparative analysis of flavor quality of "863" ecologically cultured pond crabs and purse seine crabs in Yangcheng Lake area(1)The results of free amino acid research showed that the total free amino acid content:pond male crab>pond female crab>lake male crab>lake female crab,the total free amino acid content in male crab is generally greater than female crab.The pond crab did not detect asp.Cys-s was not detected in pond male crabs and lake female crabs.Flavor AA is the source of fresh amino acids.The content of gly in females of Flavor AA is significantly higher than that of females in lakes(P<0.05).The contents of thr and pro in pond males are significantly higher than those in lakes(P<0.05);the ala content of pond-raised female crabs was significantly lower than that of lake-raised female crabs(P<0.05).The content of leu in males in bitter taste amino acids was significantly lower than that in lake males(P<0.05).The tyr content of odorless amino acids in pond male crabs was significantly higher than that in lake male crabs(P<0.05).(2)The results of taste nucleotides showed that the highest content of taste nucleotides in pond crabs and lake crabs were AMP;the AMP content of pond females was significantly higher than that of lake females(P<0.05).The highest nucleotide value was the content of AMP in pond female crabs,and was significantly higher than that in lake female crabs(P<0.05).The contents of HXR,IMP and GMP in pond male crabs were significantly higher than those in lake male crabs(P<0.05);HX content was significantly lower than that in lake male crabs(P<0.05).(3)The results of volatile flavor materials showed that the volatile flavor substances were detected by headspace solid phase microextraction-gas chromatography-mass spectrometry.A total of 13 aldehydes,12 ketones and 12 alcohols were detected.There are 69 kinds of volatile flavor substances,including 17 kinds of hydrocarbons,3 kinds of aromatics,3 kinds of furans,2 kinds of nitrogens,3 kinds of sulfurs,and esters.In this experiment,the most types of hydrocarbons were detected,a total of 17 species,and the hydrocarbons in pond crabs were significantly higher than those in lake crabs(P<0.05).The substance detected only in the male crab was phenylacetaldehyde;only the female crab detected styrene,o-xylene,dimethyl sulfide;the only substance detected in the male crab was 3-Buten-2-one,4-cyanocyclohexene,2,6,10,14-tetramethylpentadecane.The substances detected only inpondcrabsweredien-2-one,CIS-4-heptenol,2-aminopropane,hexamethylcyclotrisilox ane,ethylbenzene;only detected in crabs The substance is ethylene glycol monobutyl ether.The content of 2,3-pentanedione in pond male crab was significantly higher than that in lake male crab(P<0.05).The content of CIS-4-heptenol in pond female crab was significantly higher than that in lake female crab(P<0.05).).The content of methylheptenone,1-octene-3-one and dodecane in pond male crabs was significantly lower than that in lake male crabs(P<0.05);2-anthone and ketones in pond female crabs The subtotal content of the meter,pentanol and alcohol was significantly lower than that of the lake female(P<0.05).From the perspective of flavor quality,the quality of the pond crab under the“863”ecological farming mode is excellent,and it is a high quality crab that meets the market demand.