循环水系统短期禁食改善草鱼和斑点叉尾鮰肌肉品质

Short-term fasting in the circulating water system improves the food quality of grass carp(Ctenopharyngodon idella)and channel catfish(Ictalurus punctatus)

试验以池塘养殖的草鱼(Ctenopharyngodon idella)和斑点叉尾鮰(Ictalurus punctatus)为研究对象,在循环水系统中进行为期28 d的短期禁食,通过比较不同禁食时间下、鱼体不同部位肌肉的营养成分,以及背部肌肉的质构特性、持水力和肌肉组织形态学变化,探讨在循环水系统中禁食对商品鱼食用品质的影响。在不同禁食时间中,草鱼和斑点叉尾鮰各部位的肌肉粗脂肪含量在第14 d时显著降低(P<0.05)。草鱼粗蛋白质含量在28 d开始降低,斑点叉尾鮰粗蛋白质含量在7 d前增加随后降低的趋势(P>0.05)。2种鱼肌糖原的含量均为7 d前降低,随后增加的趋势(P>0.05)。草鱼禁食28 d、斑点叉尾鮰禁食21 d时,背部肌肉系水力最小;背部肌肉硬度、咀嚼性显著增加(P<0.05),肌纤维面积显著减小(P<0.05)、肌纤维密度增加,肌纤维内脂滴数量减少。本试验表明,在循环水系统中,短期禁食影响草鱼和斑点叉尾鮰的鱼肉品质,草鱼禁食28 d、斑点叉尾鮰禁食21 d效果最佳。在生产实践中运用此方法改善鱼肉食用品质具备较强的可行性,相关结果为鱼类食用品质改善提供理论参考。

Ctenopharyngodon idella and Ictalurus punctatus raised in ponds were subjected to short-term fasting in the circulating water system for 28 d to investigate the impact of fasting on the edible quality of commercial fish.The nutritional composition of muscles,as well as the texture characteristics,hydraulic properties,and morphological changes of the dorsal muscles were also examined under various fasting times and body segments of the fish.Varied body forms of grass carp and channel catfish had significantly varied amounts of muscle nutrients.The muscle crude fat level of grass carp and channel catfish significantly decreased after 14 d-fasting intervals at(P<0.05).The crude protein content of channel catfish grew before 7 d-fasting and thereafter fell(P>0.05),while the crude protein content of grass carp started to decline at 28 d.Muscle glycogen levels in both fish dropped before 7 d-fasting and then rose(P>0.05).The dorsal muscles were the least hydraulic in grass carp and channel catfish after short term-fasting of 28 d and 21 d,respectively(P<0.05).Fasting for 28 d in grass carp and 21 d in channel catfish resulted in a large increase in the hardness and chewiness of the dorsal muscles(P<0.05),a significant decrease in the area of the muscle fibres(P<0.05),an increase in the density of the muscle fibres,and a significant decrease in the number of lipid droplets in the muscle fibres.This experiment demonstrated that short-term fasting might greatly increase the flesh quality of grass carp and channel catfish in the circulating water system,which the grass carp in 28 d-fasting and channel catfish in 21 d-fasting were the best.It is feasible to use this method to improve the fish quality in production practice.And the experimental results provide a theoretical reference for the improvement of fish food quality.