基质辅助激光解析/电离飞行时间质谱结合化学计量学技术筛查原奶掺假研究

Study on screening adulteration of raw milk by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry combined with chemometrics

中文关键词:  基质辅助激光解析/电离飞行时间质谱法  鲜奶  掺假  主成分分析

英文关键词:matrix-assisted laser desorption/ionization time-of-flight mass spectrometry  raw milk  adulteration  principal component analysis

中文摘要:

      目的 建立基质辅助激光解析/电离飞行时间质谱(matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, MALDI-TOF)结合化学计量学的方法快速筛查鲜奶掺假。方法 样品经0.1%三氟乙酸水溶液稀释50倍, 与10 mg/mL芥子酸溶液等体积混合, 取2 μL混合液点靶板, 待样品干燥后载入基质辅助激光解析/电离飞行时间质谱, 在线性模式下采集数据。通过主成分分析(principal component analysis, PCA)分析不同来源的数据, 建立鲜奶蛋白质信息数据库。通过检测掺假样品, 结果与数据库进行比较, 评估检测方法性能。结果 确定了MALDI-TOF蛋白质图谱可作为鲜奶的指纹图谱。建立了一个涉及2个产地和2个季节的鲜奶蛋白质信息数据库。该方法能够检测含有0.3% (m:m)猪皮明胶、大豆分离蛋白或乳清蛋白的掺假样品。方法操作简单快速, 从进样到获得结果, 一个样品仅需几分钟。结论 MALDI-TOF结合化学计量学方法能够快速检测在0.3% (m:m)浓度下含有猪皮明胶、大豆分离蛋白或乳清蛋白的鲜奶掺假。

英文摘要:

      Objective To establish a rapid screening method of raw milk adulteration by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) combined with chemometrics. Methods The samples were firstly diluted with 0.1% trifluoroacetic acid aqueous solution by 50 folds, then mixed with 10 mg/mL sinapic acid solution in an equal volume, and 2 μL of the mixed solution was taken as the target plate, after the samples were dried, they were loaded into matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, where data were collected in linear mode. The data from different sources were analyzed by principal component analysis (PCA) to establish the fresh milk protein information database. The performance of the test method was evaluated by detecting adulterated samples and comparing them to a database. Results It was determined that the MALDI-TOF protein chromatogram could be used as the fingerprint of fresh milk. A fresh milk protein information database covering 2 origins and 2 seasons was established. This method was capable of detecting adulterated samples containing 0.3% (m:m) pigskin gelatin, soy protein isolate, or whey protein. This method was simple and rapid to operate, requiring only a few minutes for one sample from injection to results. Conclusion MALDI-TOF combined with chemometrics can quickly detect adulteration of fresh milk containing pigskin gelatin, soy protein isolate or whey protein at the concentration of 0.3% (m:m).