5 种淡水鱼肌肉热特性比较研究

为研究不同品种名优淡水鱼冷藏保鲜及热加工的特性，采用差示扫描量热法研究武昌鱼、草鱼、黄颡鱼、鲈鱼和鳜鱼5 种新鲜淡水鱼鱼肉的水分含量、冰点、变性温度、变性热焓和比热容并进行品种间的比较。结果发现：5 种淡水鱼冰点分布在－0.57～－0.1 ℃之间；50 ℃附近热吸收峰起始温度分布在37～41.57 ℃之间，终止温度分布在60.47～62.33 ℃之间；变性热焓在1.680 0～2.499 7 J/g之间；70 ℃附近热吸收峰的起始温度分布在66.33～71.13 ℃之间，终止温度分布在73.60～82.20 ℃之间，变性热焓在0.418 0～0.512 2 J/g之间；鱼肉的比热容在1.658 0～3.862 3 J/（g·K）之间。结果表明：在5 种新鲜淡水鱼中，武昌鱼水分含量和冰点相对较低；草鱼肌球蛋白和鳜鱼肌动蛋白变性温度和变性热焓相对较高，蛋白质稳定性更高；新鲜鱼肉的比热容高于冻结鱼肉，加工后鱼肉的比热容高于未加工鱼肉。

Comparison of Thermal Properties of Muscles from Five Kinds of Freshwater Fish

The study was intended to investigate comparatively the thermal properties of muscles from 5 different freshwater
fish (Megalobrama amblycephala, Ctenopharyngodon idellus, Pelteobagrus fulvidraco, Lateolabras janopicus and Siniperca
chuatsi) by differential scanning calorimetry (DSC), including moisture content, freezing point, denaturation temperature,
denaturation enthalpy and specific heat capacity. Results showed that the freezing points of the five fish ranged from ?0.57 to
?0.10 ℃; the onset temperature of decalescence peak around 50 ℃ ranged from 37.00 to 41.57 ℃, the conclusion temperature
ranged from 60.47 to 62.33 ℃, and the denaturation enthalpy ranged from 1.680 0 to 2.499 7 J/g. The onset temperature of
decalescence peak around 70 ℃ ranged from 66.33 to 71.13 ℃, the conclusion temperature ranged from 73.60 to 82.20 ℃, and
the denaturation enthalpy ranged from 0.418 0 to 0.512 2 J/g; the specific heat capacity ranged from 1.658 0 to 3.862 3 J/(g·K).
As demonstrated by this study, among the five species examined, freezing point and moisture content of Megalobrama
amblycephala were relatively lower; denaturation temperature and denaturation enthalpy of Ctenopharyngodon idellus
myosin and Siniperca chuatsi actin were relatively higher, which means that they had higher protein stability. Moreover, the
specific heat capacity of fresh fish was higher than that of frozen fish; the specific heat capacity of processed fish was higher
than that of the unprocessed one.