大鳍鱯的消化能力与营养价值

采用常规方法测定了大鳍鳠(Mystusmacropterus)的消化道指数,其比肠长、比胃重、比肠重、比肝胰脏重和比内脏重分别为0.531±0.006、0.014±0.006、0.017±0.003、0.0084±0.0029和0.070±0.011。体重与体长的回归方程Y=0.1238X2.8388(r=0.9949,P<0.01);大鳍鳠的胃、前肠、中肠和后肠中消化液的pH值分别为:3.0～3.8、6.6～7.4、7.2～8.2、7.2～7.9,且消化道各部分具有较高的蛋白酶和淀粉酶活性,蛋白酶的活性为中肠>前肠>肝胰脏>后肠>胃;而淀粉酶的活性则为前肠>后肠>中肠>肝胰脏>胃;全鱼和肌肉中粗蛋白的含量分别为62.09±3.8%和68.28±4.6,粗脂肪含量分别为15.33±1.7和21.87±2.9;肌肉中必需氨基酸的含量占氨基酸总量的40.76%,鲜味氨基酸的含量为总氨基酸量的29.70%。综合肌肉的常规营养成分和氨基酸分析的结果,表明大鳍鳠是一种营养价值较高的优质鱼类。

Digestive ability and nutritive value of Mystus macropterus

With normal regulat ions method, the digestive tube indices of Mystus macropterus such as ratio of intestine gut length to body length was 0. 531 ? 0. 006 while the ratio of stomach, intestine gut, hepatopanceras or viscera weight to body weight were 0. 014 ? 0. 006, 0. 017 ? 0. 003, 0. 0084 ? 0. 0029 and 0. 070 ? 0. 011, respectively . The regression of body weight with body length was Y= 0. 1238X2. 8388( r = 0. 9949, P < 0. 01) . The pH value of stomach, anterior intestine, middle instestine, posterior intestine and hepatopancreas were 3. 0- 3. 8, 6. 6- 7. 4, 7. 2- 8. 2 and 7. 2- 7. 9, respectively. At the same time, the activities of protease were middle instestine> anterior intestine > hepatopancreas > posterior intestine> stomach; the activities of amylase were anterior intestine> posterior intest ine> middle instestine> hepatopancreas> stomach. The crude protein of muscle and whole body were 62. 09 ? 3. 8% and 68. 28 ? 4. 6, repectively ; the crude fat were 15. 33 ? 1. 7 and 21. 87 ? 2. 9, repectively. The essential amino acids accounted for 40. 76% of total amino acids and the delicious amino acid accounted for 29. 70% of total amino acids. It was indicated that the nutritive value of Mystus macropterus is higher than that of the common carp and grass carp.