海蜇胶原蛋白的制备及理化性质研究

Preparation and physicochemical properties of the jellyfish collagen

以海蜇加工下脚料为原料,建立在中低温条件下,以柠檬酸为提取剂的胶原蛋白制备工艺,并对海蜇胶原蛋白的理化性质进行分析.结果表明,海蜇胶原蛋白的最佳酶法提取工艺条件为:提取温度15℃、柠檬酸浓度0.05 mol·L^(-1)、胃蛋白酶添加量1.5%、料液比1∶2.0(w∶V)和提取时间8 h,在该条件下胶原蛋白提取率为97.41%.SDS-PAGE分析结果表明,其可能结构为[α_1]_3;胶原蛋白中,甘氨酸、脯氨酸和羟脯氨酸分别占总氨基酸的25.16%、7.62%和9.32%;傅里叶红外光谱分析表明,其保留了完整的三螺旋结构;黏度及溶解性特征显示,其等电点pI值在6~9之间;在pH值≤1和≥10范围,结构趋于不稳定,热变性温度为22.7℃,在大于1.0 mg·mL^(-1)的NaCl溶液中基本析出.

To analyze the physicochemical properties of jellyfish collagen,the leftover jellyfish was used as raw material,and treated with preparation technology.The preparation technology for collagen was based on the low-temperature condition and citric acid which worked as an extraction agent.The optimum enzymatic extraction condition was:temperature 15℃,0.05 mol·L-1 citric acid concentration,1.5%(mass fraction,the following are the same as)pepsin addition,1∶2.0(w∶V)solid-liquid ratio and 8 h extraction time.The jellyfish collagen extraction yield of 97.41%under this condition.By performing purified collagen on sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDSPAGE),the result demonstrated that collagen as Type I marine collagen in which threeα1 chains each other.In collagen,glycine(Gly),proline(Pro)and hydroxyproline(Hyp)account for 25.16%,7.62%and 9.32%of the total amino acids,respectively.Fourier transform infrared spectroscopy(FTIR)data of the collagen revealed that stable triple-helical structure was existence.Meanwhile,the viscosity and solubility of purified collagen were measured to evaluate the pI value of collagen about 6 to 9.When the pH value is less than or equal to 1 and above 10 range,structure tended to be unstable,thermal denaturation temperature 22.7℃.According to the experimental results,collagen would precipitate completely in NaCl solution when its mass concentration was above 1.0 mg·mL-1.