不同养殖模式对中华绒螯蟹品质的影响

DIFFERENT CULTURE MODES ON QUALITY OF ERIOCHEIR SINENSIS

为探究不同养殖模式对中华绒螯蟹(Eriocheir sinensis)品质的影响,实验采集了阳澄湖地区池塘养殖模式和盘锦地区稻田养殖模式的中华绒螯蟹(分别简称池塘蟹和稻田蟹),比较其组织系数、总可食率、游离氨基酸组成、类胡萝卜素含量、抗氧化酶活性及DNA甲基化水平的差异。结果显示:稻田蟹性腺指数(GSI)、出肉率(MY)、总可食率(TEY)均高于池塘蟹,其中MY和TEY差异极显著(**P<0.01);池塘蟹的甜味和鲜味氨基酸含量更高,而稻田蟹的总氨基酸含量更高;类胡萝卜素在池塘蟹肝胰腺和卵巢中的含量均显著高于稻田蟹,并且在雌蟹各组织中的含量差异极显著(**P<0.01);在两种养殖模式下,雄蟹肝胰腺和雌蟹肌肉中的丙二醛(MDA;**P<0.01)含量和超氧化物歧化酶(SOD;*P<0.05)活性有显著差异,而各组织中过氧化氢酶(CAT)活性均无显著差异(P>0.05)。此外,在两种养殖模式下,河蟹不同组织的DNA甲基化呈显著差异。上述结果表明,不同的养殖模式对中华绒螯蟹的总可食率、游离氨基酸含量及类胡萝卜素含量具有显著影响,从而形成不同的品质。而DNA甲基化水平的显著差异,预示着不同的养殖模式可能通过DNA甲基化的变化调控基因的表达从而实现风味的变化。

In order to explore the effects of different culture modes on the quality of Eriocheir sinensis,commonly known as Chinese mitten crabs,specimens(referred to as pond crab and paddy crab)were collected from the Yangcheng Lake area and the Panjin area,respectively.Their tissue coefficient,total availability,free amino acid composition,carotenoid content,antioxidant enzyme activity,and DNA methylation level were compared.The results showed that the gonadal index(GSI),meat yield(MY),and total availability(TEY)of paddy crab exceeded those of pond crab.MY and TEY exhibited significant differences between the two crab samples(P<0.01).The pond crab displayed higher levels of sweet and umami amino acids,while the paddy crab exhibited a higher total amino acid content.Carotenoids levels in the hepatopancreas and ovaries of pond crabs were notably higher than those in paddy crab,with significant variations observed in female crab tissues(P<0.01).Levels of malondialdehyde(MDA)in the hepatopancreas of male crab and muscle tissues of female crabs under both culture methods differed significantly(P<0.01),as did superoxide dismutase(SOD)activity(P<0.05).Catalase activity exhibited significant differences in various tissues(P>0.05),while catalase(CAT)activity did not.In addition,DNA methylation levels in different E.sinensis tissues varied significantly under the two culture modes.The results indicated that different farming patterns combined with climatic factors had significant effects on the total availability,free amino acid content,and DNA methylation level of E.sinensis.The significant differences in DNA methylation levels resulted in differential expression of gene expression,indicating that different farming patterns contribute to variations in crab quality.