不同蛋白质源对草鱼和花鲈肉质影响的比较研究

本试验旨在比较不同蛋白质源对草鱼(Ctenopharyngodon idellus)及花鲈(Lateolabrax japonicas)体成分、肌肉游离氨基酸组成及鱼片质构特性的影响。设计草鱼和花鲈饲料各3种,分别等氮等能。3种草鱼试验饲料分别为以鱼粉为唯一蛋白质源的CI-FM组(对照组),以混合植物蛋白质(豆粕和大豆浓缩蛋白)替代80%鱼粉的CI-PPB80组及以混合植物蛋白质替代100%鱼粉的CI-PPB100组。3种花鲈试验饲料分别为以鱼粉为唯一蛋白质源的LJ-FM组(对照组),以混合植物蛋白质(棉籽浓缩蛋白和大豆浓缩蛋白)替代50%鱼粉的LJ-PPB50组和以混合植物蛋白质替代100%鱼粉的LJ-PPB100组。草鱼初始体重为(153.40±0.30)g,随机分为3组,每组3个重复,每个重复20尾鱼;花鲈初始体重为(12.97±0.03)g,随机分为3组,每组4个重复,每个重复25尾鱼。饲喂8周后,检测2种试验鱼的体成分、肌肉游离氨基酸含量及鱼片质构特性、剪切力、滴水损失及胶原蛋白含量。结果表明:与CI-FM组相比,CI-PPB100组草鱼肌肉粗脂肪含量显著降低(P0.05),粗灰分含量显著升高(P0.05);而花鲈肌肉粗脂肪含量则随替代水平的升高呈现先上升后下降的趋势,表现为LJ-PPB50组显著高于LJ-PPB100组(P0.05)。草鱼肌肉总游离氨基酸及生物胺前体含量各组间无显著差异(P0.05);随着替代水平的升高,花鲈肌肉总游离氨基酸及呈味氨基酸含量显著降低(P0.05),生物胺前体含量显著升高(P0.05)。2种试验鱼肌肉中存在各自的特异性成分。2种试验鱼生、熟鱼片的质构特性差异较大。草鱼的CI-FM组和花鲈的LJ-FM组生鱼片的硬度、黏性、咀嚼力、回弹力及剪切力均分别显著高于同鱼种的其他2组(P0.05)。对于熟鱼片,草鱼的CI-PPB80组内聚力显著高于其他2组(P0.05),其他各项指标各组间无显著差异(P0.05);花鲈的LJ-PPB100组硬度及黏附性显著高于LJ-FM组(P0.05),其他各项指标各组间无显著差异(P0.05)。根据结果,混合植物蛋白质替代鱼粉后降低了草鱼和花鲈鱼体脂肪的蓄积,对草鱼肌肉总游离氨基酸含量不造成影响,使花鲈肌肉呈味氨基酸含量下降,必需氨基酸含量减少,生物胺前体含量升高,货架期缩短;高植物蛋白质源饲料使得草鱼和花鲈的肉质均出现明显下降,而高鱼粉饲料可以保证2种试验鱼有较高的肉质。

A Comparative Study：Effects of Different Protein Sources on Flesh Quality of Grass Carp (Ctenopharyngodon idellus) and Japanese Seabass (Lateolabrax japonicas)

This study aimed to compare the effects of different protein sources on body composition, free ami?no acid composition in muscle and fillet texture characteristics of grass carp ( Ctenopharyngodon idellus) and Japanese seabass ( Lateolabrax japonicas) . Three isoenergetic and isonitrogenous experimental diets were de?signed for grass carp and Japanese seabass, respectively. The control group diet for grass carp used low temper?ature steam?dried fish meal as sole protein source, and used blended plant protein ( soybean meal and soybean protein concentrate) to replace 80% and 100% fish meal, respectively, which were named as CI?FM, CI?PPB80 and CI?PPB100 groups, respectively. The control group diet for Japanese seabass used Peru fish meal as sole protein source, and used blended plant protein ( cottonseed protein concentrate and soybean protein con?centrate) to replace 50% and 100% fish meal, respectively, which were named as LJ?FM, LJ?PPB50 and LJ?PPB100 groups, respectively. Each grass carp diet was fed to 3 replicates with 20 grass carp initial body weight of (153.40±0.30) g], and each Japanese seabass diet was fed to 4 replicates with 25 Japanese seabass (initial body weight of (12.97±0.03) g]. After an 8?week experiment, body composition, free amino acid composition in muscle and fillet texture characteristics, drop loss, shear force and collagen content were inves?tigated. The results showed that muscle ether extract content of grass carp in CI?PPB100 group were significant?ly decreased ( P<0.05) , while ash content was significantly increased compared with CI?FM group ( P<0.05) . However , the muscle ether extract content of Japanese seabass was firstly increased and then down with the re?placement level increasing, and showed LJ?PPB100 group was significantly higher than LJ?PPB50 group ( P<0.05) . No differences were observed in the muscle total free amino acid ( TFAA) and biogenic precursor con?tents among all groups of grass carp ( P>0.05) . With the replacement level increasing, the muscle TFAA and flavor amino acid ( FAA) contents of Japanese seabass were significantly decreased ( P<0.05) and biogenic precursor content was significantly increased ( P<0.05) . We found several specific components in both species. Furthermore, the texture characteristics of raw and cooked fillets showed much more significant difference be?tween the two species. For both of fish, the raw fillets in full fish meal groups showed significantly higher hard?ness, gumminess, chewiness, resilience and shear force than those of blended plant protein groups ( P<0.05) . The cohesiveness of cooked fillets of CI?PPB80 group was significantly higher than that of other two groups ( P<0.05) , but no significant differences were observed in the other indexes ( P>0.05) . The hardness and ad?hesive of cooked fillets of LJ?PPB100 group were significantly higher than those of LJ?FM group ( P<0.05) , but no significant differences were observed in the other indexes ( P>0.05) . In conclusion, using blended plant protein to replace fish meal can reduce fillet lipopexia for two species, and has no effect on muscle TFAA con?tent of grass carp, but can reduce the muscle FAA, biogenic precursor and essential amino acid contents, and shorten the shelf life of Japanese seabass. High plant protein diet can reduce flesh quality, while high fish meal diet can ensure a better flesh quality of grass carp and Japanese seabass.