食品科学

• 工艺技术 • 上一篇    下一篇

奶粉中游离氨基酸的提取工艺参数优化及同时测定

加列西·马那甫1,德娜·吐热汗2,李俊芳1   

  1. 1.新疆农业大学化学工程学院,新疆 乌鲁木齐 830052;2.新疆农业大学数理学院,新疆 乌鲁木齐 830052
  • 出版日期:2014-10-25 发布日期:2014-11-07

Optimization of Extraction Parameters and Simultaneous Determination of Free Amino Acids in Milk Powder

JIALIEXI·Manafu1, DENA·Turehan2, LI Jun-fang1   

  1. 1. College of Chemical Engineering, Xinjiang Agricultural University, Ürümqi 830052, China;
    2. College of Mathematics and Physics, Xinjiang Agricultural University, Ürümqi 830052, China
  • Online:2014-10-25 Published:2014-11-07

摘要:

根据单因素试验与响应面分析法中的Box-Behnken试验设计原理对影响奶粉游离氨基酸提取量的料液比、硫酸锌质量分数和离心时间3 个因素进行优化,并采用偏最小二乘法对以上游离氨基酸的模拟混合试样进行同时测定。结果表明,奶粉游离氨基酸的最佳提取条件为料液比1∶3.02(g/mL)、沉淀剂中硫酸锌质量分数10.23%、离心时间6.79 min,在此条件下,提取量为170 μg/g。硫酸铜与甘氨酸、谷氨酸、缬氨酸和苯丙氨酸反应生成的络合物,由于吸收光谱重叠严重,用光度法难以对单一组分进行同时测定。偏最小二乘法对游离氨基酸的模拟混合试样进行同时测定的结果显示,回收率98.2%~99.2%;相对预报误差为1.7%~2.9%。

关键词: 奶粉, 游离氨基酸, 响应面分析法, 提取, 偏最小二乘法, 同时测定

Abstract:

Three variables (operating parameters) affecting the extraction efficiency of free amino acids from milk powder,
solid-to-solvent ratio, zinc sulfate concentration (for protein precipitation), and centrifugation time, were optimized by
response surface analysis (RSA) based on a Box-Behnken design. Simultaneous determination of mixed free amino acids
and free amino acids in milk powder samples was performed by visible spectrophotometry combined with partial least
square (PLS). The results showed that under the optimal conditions: solid-to-solvent ratio, 1:3.02 (g/mL); zinc sulfate
concentration, 10.23%; and centrifugation time, 6.79 min, the extraction yield was 170 μg/g. The complexation of copper
sulfate with glycine, glutamic acid, valine and phenylalanine resulted in highly overlapping absorption spectra when mixed
together, which made it difficult to simultaneously determine the individual components. The simultaneous determination of
mixed free amino acids using PLS demonstrated that the recovery rate was 98.2%–99.2% and the relative prediction error
(RPE) was 1.7%–2.9%.

Key words: milk power, free amino acids, response surface analysis, extraction, partial least squares, simultaneous determination

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