金鲳鱼内脏酸性蛋白酶的提取及应用研究

Extraction and application of acid protease from Golden Pompano viscera

以金鲳鱼为原料,依次通过p H7.0的磷酸钠缓冲液浸提法和0%~55%硫酸铵分级沉淀法,从内脏中初步纯化出蛋白酶。探讨了温度和p H对酶活力的影响。蛋白粗酶分别应用于罗非鱼鱼皮明胶水解产物的制备、罗非鱼鱼鳞中提取胶原蛋白和虾壳中提取虾青素,同时与猪胃蛋白酶进行了比较。结果表明,金鲳鱼内脏蛋白酶的最适温度为25℃,最适p H为4.0。该酶应用于制备罗非鱼鱼皮明胶水解产物,其酶解能力强于猪胃蛋白酶;应用于提取罗非鱼鱼鳞胶原,胶原的得率为0.65%,不及猪胃蛋白酶;应用于提取虾壳中的虾青素,得到虾青素含量为(65.41±2.51)μg/g,其DPPH自由基清除率为(84.97±2.62)%,活性强于猪胃蛋白酶提取组。因此,研究结果为金鲳鱼内脏蛋白酶进一步利用提供了理论基础。

Golden Pompano was taken as raw material in the present study, crude enzymes were obtained from its viscera by homogenisation of tissue in sodium phosphate buffer（p H 7.0） and precipitation by 0%~55% ammonium sulfate. The effects of temperature and p H on the enzymatic activity were investigated. Protease after precipitation was employed to prepare gelatin hydrolyzate of tilapia fish skin, and extracted collagen from tilapia fish scale and astaxanthin from shrimp shell in comparison with porcine pepsin. The experimental results shows that, the optimum p H is 4.0 and the most suitable temperature is 25 ℃. For the hydrolysis ability of gelatin of tilapia fish skin, the hydrolysis ability is stronger than porcine pepsin. For the extraction of collagen from tilapia fish scale by protease of Golden Pompano viscera, the yielding rate of collagen was 0.65%, but lower than the porcine pepsin. For the extraction of waste shrimp astaxanthin, the astaxanthin content was（65.41±2.51） μg/g, DPPH radical scavenging rate was（84.97±2.62）%, stronger than the porcine pepsin. Thus, theoretical foundation was laid for the utilization of protease from Golden Pompano viscera.