养殖暹罗鳄肉肌原纤维蛋白的理化性质

筛选养殖暹罗鳄肌原纤维蛋白含量最高部位，提取并分析离子强度、pH值和温度对肌原纤维蛋白溶液的溶解性、乳化性和热诱导凝胶特性的影响。结果表明：暹罗鳄尾部肌原纤维蛋白所占比例最高（（7.95±0.12） g/100 g，以湿质量计），暹罗鳄尾肉中肌原纤维蛋白主要为肌球蛋白重链、副肌球蛋白、肌动蛋白和原肌球蛋白。在低离子强度条件下，肌原纤维蛋白的溶解度和乳化性较低，但有良好的凝胶特性，随着离子强度的升高，肌原纤维蛋白的溶解度和乳化性升高，凝胶特性则呈现下降趋势。随着pH值升高，肌原纤维蛋白溶解度呈现先迅速下降后升高的趋势，乳化性和凝胶特性则呈现持续缓慢下降的趋势，其中溶解度和保水性在pH 5.5达到最低点。随着热变温度升高，其凝胶特性显著增加，保水性先下降后略有升高，在低温（40 ℃）下有较好的保水性，在80 ℃保水性升高至又一峰值随后下降。结论：肌原纤维蛋白在NaCl浓度0.2 mol/L进行调配，并在80 ℃条件下加热处理，暹罗鳄肉类产品将具有较好的质构特性及保水性。

Physico-chemical Properties of Myofibrillar Proteins from Cultured Crocodile (Crocodylus siamensis)

The highest content of myofibrillar proteins of edible parts from cultured crocodile (Crocodylus siamensis) was
investigated. The extracted myofibrillar proteins were explored for the effects of NaCl concentration, pH and temperature
on their solubility, emulsifying properties and gel properties. The results showed that the content of myofibrillar proteins
in tail muscle ((7.95±0.12) g/100 g on a wet weight basis) was the highest; the electrophoretic patterns indicated that the
myofibrillar proteins mainly included myosin, paramyosin, actin, tropomyosin and troponin, and at low ionic strength had
poor solubility and emulsifying properties but good gel properties. The solubility and emulsifying properties increased
with increasing ionic concentration, while the opposite trend was observed for gel properties. With an increase in pH, the
solubility dramatically increased first but decreased later, and the emulsifying properties and gel properties showed a trend
of slow decline. The solubility and water-holding capacity (WHC) reached the lowest level at pH 5.5. With increasing
temperature, the gel properties increased significantly, and the WHC initially decreased followed by a slight increase,
reaching a desired level at a lower temperature (40 ℃) . Taken together, good texture quality and WHC of meat products
from Crocodylus siamensis can be obtained for myofibrillar proteins with 0.2 mol/L NaCl and heating at 80 ℃.