以草鱼鳞为原料提取明胶，首先采用单因素试验明确了明胶提取温度为60 ℃~80 ℃，时间为6 h。在此基础上采用60 ℃~70 ℃~80 ℃三段式加热的梯度升温法提取草鱼鳞明胶，并以恒温提取法（60 ℃、70 ℃和80 ℃）为对照组，对所制备的明胶理化特性进行了比较研究。实验表明，梯度升温法所得明胶相比市售明胶和对照组，含有更多的高分子量组分（130~250 ku），使其具有更高的凝胶强度，傅里叶变换红外光谱显示梯度升温法所得明胶具有明胶特有的典型酰胺带，其溶胶-凝胶点和热变性温度居于恒温提取法60 ℃组和80 ℃组之间，但提取率和凝胶强度均相对较高，且灰分含量低于0.20%，脂肪含量低于0.60%。综上所述，采用梯度升温法提取明胶兼顾了提取率和明胶品质，具有较好的应用前景。

Gelatin was extracted from grass carp (Ctenopharyngodon idella) scales under the conditions (60 ℃~80 ℃, 6 h) determined by single-factor tests. The physicochemical properties of gelatin extracted by the methods of gradient increasing temperatures (60 ℃~70 ℃~80 ℃)were studied, with gelatin extracted by constant temperature extraction method(60 ℃, 70 ℃ and 80 ℃) and commerical gelatin as control. SDS-PAGE showed that the gelatin obtained by gradient increasing temperature had a higher molecular weight (130~250 ku) and a higher gel strength than the commercial gelatin and the control group. FT-IR spectra showed that the gelatin obtained by the gradient increasing temperature had a typical amide band of gelatin. The sol-gel point and thermal denaturation temperature for the gelatin extracted by gradient increasing temperature were between 60 ℃ and 80 ℃, but the extraction rate and gel strength were relatively high, the ash content was less than 0.20%, and the fat content was less than 0.60%. In summary, the method of gradient increasing temperature can be used to extract gelatin with high extraction rate and good quality, and has a good application prospects.

国家自然科学基金青年基金(21506070)；中央高校基本科研业务费专项基金（2662018JC019）；现代农业产业技术体系专项资金（CARS-45-27）