双缩脲比色法分析三氯乙酸沉淀乳蛋白效果探讨

Study on the effect of precipitation of milk protein by trichloroacetic acid analyzing with biuret spectrophotometry method

通过对双缩脲比色法分析加热条件、不同浓度的三氯乙酸(TCA)沉淀牛乳蛋白的效果,以及pH影响双缩脲比色法分析TCA沉淀牛乳蛋白的效果进行分析。结果表明,采用双缩脲比色法分析TCA沉淀乳蛋白的效果:当使用标准双缩脲试剂时,受TCA浓度的影响较大,需TCA浓度≤15%;当TCA浓度>15%时,需调整pH至11以上;pH≥11时,碱性强度微弱的变化对OD值结果无明显影响;加热煮沸与未加热煮沸对TCA沉淀牛乳蛋白的效果差别无明显规律。

The effect of precipitation of milk protein by heating and different concentration of trichloroacetic acid（TCA）was analyzed by biuret spectrophotometry method,and it was influenced by pH that the effect precipitation of milk protein by TCA.Results showed that it was influenced by concentration of TCA that the effect of precipitation milk protein by TCA were analyzed by biuret spectrophotometry method,when using standard biuret spectrophotometry,and the concentration of TCA≤15%.When TCA15%,it must adjust the pH above 11.When pH≥11,the delicacy change of pH didn’t affect OD.There was no obvious difference between heating and not heating on the precipitation effect of milk protein by TCA.