【摘要】 为探究罗非鱼源胶原蛋白肽含量的快速测定方法,以罗非鱼皮胶原蛋白肽为对照品,改良双缩脲比色法测定肽含量的操作方法,考察显色络合物最大吸收波长、线性拟合度高的肽和三氯乙酸(trichloroacetic acid,TCA)用量范围、pH值;在优化条件下对标准曲线进行重复性、精密度评价以及加样回收率实验;研究本方法对不同分子质量罗非鱼皮及鱼鳞胶原蛋白肽体系检测的适用性。结果显示,当胶原蛋白肽(标称分子质量3 kDa)质量浓度在0.3～1.5 mg/mL范围内,使用13%TCA溶液,调整体系pH 12.5,在波长545 nm处检测,吸光度与肽质量浓度线性拟合好(R2=0.999),标准曲线方程为y=0.144 9x+0.001 5;重复性和精密度实验得到相对标准偏差(relative standard deviation,RSD)分别为1.86%和1.84%,加样回收率分别为113.9%、109.7%,RSD分别为1.39%、1.00%;线性范围宽、重复性好、准确度高。将本法应用于不同种类罗非鱼肽产品体系的检测,加样回收率相差不大,偏差均较小,说明本法简便、快捷,适用于罗非鱼源肽含量的检测。更多还原

【Abstract】 To develop a rapid method for the determination of tilapia collagen peptide content, the colorimetric biuret method was improved using tilapia skin collagen peptide as a reference material. We determined the maximum absorption wavelength of the chromogenic complex and the concentration ranges of peptide and trichloroacetic acid(TCA) and pH for high linearity. The repeatability, precision and recovery of the improved method were tested under optimized conditions. The applicability of this method to the detection of collagen peptides from the skin and scales of tilapia with different molecular masses was also studied. The results showed that the absorbance was linearly fitted with peptide concentration ranging from 0.3 to 1.5 mg/mL under the following conditions: 13% TCA, adjustment of the system pH to 12.5, and detection wavelength 545 nm, and the following equation was obtained: y = 0.144 9 x + 0.001 5(R2 = 0.999). The relative standard deviation(RSD) for repeatability and precision were 1.86% and 1.84%, respectively. The average spiked recoveries with and without the addition of gelatin were 113.9% and 109.7%, with RSD of 1.39% and 1.00%, respectively. The method had wide linear range, good repeatability and high accuracy. Its application to different tilapia collagen peptides showed little differences in spiked recoveries and RSD. The improved biuret method proved to be simple, rapid and suitable for the determination of peptides derived from tilapia.更多还原