影响饲料中氨基酸含量测定的结果稳定性因素探讨

Factors affecting the stability of the determination of amino acid content in feed

本文以检测结果的稳定性为目的,通过对质控样品绘制的均值-标准差控制图的异常数据分析发现,检测结果容易受烘箱温度波动、氮气保护不足等关键因素的影响,从而导致部分氨基酸结果偏低。验证发现样品水解24 h的温度需严格控制在(110±2)℃,特别是针对温度敏感的苏氨酸和丝氨酸,当水解温度从110℃升到130℃时,苏氨酸和丝氨酸含量分别下降15.3%和34.0%(P <0.05);另外,通过比较充入氮气和添加巯基乙酸对保护蛋氨酸结果的影响发现,两种方式均能保护蛋氨酸,与对照组相比含量最高提高27.2%(P <0.05)。因此在氨基酸检测过程中,通过严格控制水解温度,必要时进行在线温度监控,同时充氮气或添加巯基乙酸对蛋氨酸进行保护,可有效提高饲料中氨基酸检测结果的稳定性。

In order to ensure the stability of the test results,this paper analyzed the abnormal data of the mean-standard deviation control chart drawn by the quality control samples,and found that the test results were easily affected by key factors such as oven temperature fluctuation and insufficient nitrogen protection,which led to the low results of some amino acids.It was found that the hydrolysis temperature of samples for 24 h should be strictly controlled at(110±2)℃,especially for temperatures-sensitive threonine and serine.When the hydrolysis temperature increased from 110 ℃ to 130 ℃,the contents of threonine and serine decreased by 15.3% and 34.0%,respectively(P < 0.05).In addition,the effects of nitrogen and mercaptoacetic acid supplementation on methionine protection were compared,and the methionine content was increased by 27.2% compared with the control group(P < 0.05).Therefore,in the process of amino acid detection,the stability of amino acid detection results in feed could be effectively improved by strictly controlling hydrolysis temperature,monitoring online temperature when necessary,and protecting methionine by filling nitrogen or adding mercaptoacetic acid.