饲料棕榈酸/(EPA+DHA)对大黄鱼抗氧化能力和肌肉品质的影响

Effects of Palmitic acid/(EPA+DHA) Ratios on Anti-oxidative Capacity and Muscle Quality of Large Yellow Croaker Larimichthys crocea

中文关键词: 大黄鱼  肌肉品质  抗氧化能力  棕榈酸  EPA+DHA

英文关键词: Large yellow croaker  Muscle quality  Anti-oxidative capacity  Palmitic acid  EPA+DHA

中文摘要:

      为探究饲料中棕榈酸/(二十碳五烯酸+二十二碳六烯酸)(EPA+DHA)对大黄鱼(Larmichthys crocea) [初始体重为(30.51±0.16) g]抗氧化能力和肌肉品质的影响，本研究以鱼粉和豆粕为主要蛋白源，EPA富含油、DHA富含油、棕榈酸和卵磷脂为主要脂肪源，分别配制棕榈酸/(EPA+DHA)比例分别为1∶5、1∶1和5∶1的3种等氮(约43%粗蛋白)、等脂(约11%粗脂肪)饲料，并分别命名为P0、P50和P100组，在海水浮式网箱中进行为期70 d的摄食生长实验，从肌肉基本指标与分子基因层面探究饲料对大黄鱼抗氧化能力与肌肉品质的影响。结果显示，P0和P50组大黄鱼肌肉具有显著高的硬度、粘附性、内聚性和咀嚼性(P<0.05)。P0组大黄鱼肌肉多不饱和脂肪酸显著高于P50和P100组(P<0.05)；P100组肌肉饱和脂肪酸显著高于P0和P50组(P<0.05)。P100组大黄鱼肌肉超氧化物歧化酶2基因(SOD2)和过氧化氢酶基因(CAT)表达水平显著高于P0和P50组(P<0.05)；P0组肌肉核因子E2相关因子基因(Nrf2)表达水平则显著高于P50组(P<0.05)，P100和P0组、P100和P50组间相比无显著差异(P>0.05)。对于超氧化物歧化酶1基因(SOD1)，P0、P50和P100组相比均无显著差异(P>0.05)。P50组大黄鱼肌肉的总抗氧化能力(T-AOC)显著低于P0和P100组(P<0.05)，P0、P50和P100组大黄鱼肌肉的总超氧化物歧化酶(T-SOD)、CAT活性及丙二醛(MDA)含量相比均无显著差异(P>0.05)。研究表明，饲料中棕榈酸含量较高时，大黄鱼肌肉质构特性降低，抗氧化能力没有受到显著影响；在饲料棕榈酸/(EPA+DHA)值发生改变时，大黄鱼肌肉品质的变化与鱼体内氧化应激和抗氧化能力之间的关联仍需进一步探究。

英文摘要:

      This study explored the effects of dietary palmitic acid/(docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]) on the anti-oxidative capacity and muscle quality of large yellow croaker (initial weight: 30.51 ± 0.16 g). Fish meal and soybean meal were used as the main dietary protein sources. DHA rich oil, EPA-rich oil, palmitic acid, and lecithin were used as the main dietary lipid sources. Three isonitrogenous (43 % crude protein) and isolipidic (11 % crude lipid) experimental diets were formulated to have 1∶5, 1∶1, and 5∶1 palmitic acid/(EPA+DHA) ratios, and called P0, P50, and P100, respectively. The feeding trial lasted for 10 weeks. Results showed that there was no significant difference in the growth rate among the three groups (P>0.05). Compared with the P100 group, the hardness, adhesiveness, cohesiveness, and chewiness of muscle in large yellow croaker fed P0 and P50 were significantly higher (P<0.05). Muscle polyunsaturated fatty acid (PUFA) content in the P0 group was significantly higher than that in the P50 and P100 groups (P<0.05). The saturated fatty acid (SFA) content of the P100 group was significantly higher than that in the P0 and P50 groups (P<0.05). The expression levels of superoxide dismutase 2 gene (SOD2) and catalase gene (CAT) in the muscle of the P100 group were significantly higher than those in the P0 and P50 groups (P<0.05). The gene expression level of muscle nuclear factor E2-related factor 2 gene (Nrf2) in the P0 group was significantly higher than that in the P50 group (P<0.05); however, there was no significant difference either between the P100 and P0 groups or between the P100 and P50 groups (P>0.05). There was no significant difference among the three groups in the expression level of superoxide dismutase 1 gene (SOD1) in muscle (P>0.05). The total anti-oxidative capacity (T-AOC) of muscle in the large yellow croaker fed P50 was significantly lower than that in the P0 and P100 groups (P<0.05). The activities of total superoxide dismutase (T-SOD) and CAT, and malondialdehyde (MDA) content of muscle showed no significant differences among all the groups (P>0.05). In conclusion, higher antioxidative capacity was found in muscle when large yellow croaker juveniles were fed with higher levels of dietary palmitic acid or (EPA+DHA). Higher dietary palmitic acid levels decreased the texture parameters in muscle.