Department of Food Science and Technology, Food Chemistry Laboratory, BOKU - University of Natural Resources and Life Sciences Vienna, Muthgasse 11, A-1190 Vienna, Austria.
J Chromatogr B Analyt Technol Biomed Life Sci. 2013 May 15;927:191-200. doi: 10.1016/j.jchromb.2012.12.006. Epub 2012 Dec 20.
A new UHPLC method for the simultaneous determination of amino acids and biogenic amines in a single run, and its first application to profile ripened acid-curd cheeses was presented. After pre-column derivatization with 6-aminoquinolyl-N-hydroxy succinimidyl carbamate (AQC), 23 amino acids and 15 amines were separated in 9min only (12min total run time), and eluates monitored using their UV response at 249nm. Limits of detection (0.05-0.29mg/100g) and quantification (0.16-0.97mg/100g), repeatability for sample preparation (1.0-6.1% RSD) and method recoveries (83-120%) were found suitable for cheese analysis. In total, 47 acid-curd cheeses classified into sub-groups like cooked, Quargel-type or grey cheeses were analyzed for their free amino acid and amine (histamine, tyramine, putrescine, cadaverine, and tryptamine) contents, which (as expected) were highlighted by a great variability. Total free amino acid levels ranged between less than 100 and more than 4000mg/100g (median 567mg/100g), implying that for some cheeses less or not ripened/fresh quark was used for production or, in contrast, a higher degree of proteolysis had occurred. For the sum of biogenic amines, median concentration was determined at 7.0mg/100g, while only 5% of all cheeses had levels higher than 161.9mg/100g. Thus, the obtained results suggest quite acceptable biogenic amine levels for (mostly underrated) ripened acid-curd cheeses, although partly exceptional high concentrations (>250mg/100g) were indeed observed in individual samples.
一种新的超高效液相色谱法用于在单次运行中同时测定氨基酸和生物胺，并首次将其应用于成熟酸凝乳奶酪的分析。经 6-氨基喹啉基-N-羟基琥珀酰亚胺基碳酸酯（AQC）柱前衍生后，仅用 9 分钟（总运行时间 12 分钟）即可分离出 23 种氨基酸和 15 种胺，洗脱液在 249nm 处监测其紫外响应。检测限（0.05-0.29mg/100g）和定量限（0.16-0.97mg/100g）、样品制备重复性（1.0-6.1%RSD）和方法回收率（83-120%）均适用于奶酪分析。总共分析了 47 种酸凝乳奶酪，分为煮熟的、Quargel 型或灰色奶酪等亚组，测定其游离氨基酸和胺（组胺、酪胺、腐胺、尸胺和色胺）含量，这些含量（如预期的那样）差异很大。总游离氨基酸水平在少于 100 至超过 4000mg/100g（中位数 567mg/100g）之间，这意味着对于一些奶酪，用于生产的未成熟/新鲜凝乳干酪较少或没有，或者相反，发生了更高程度的蛋白水解。对于生物胺的总和，中位数浓度确定为 7.0mg/100g，而只有 5%的奶酪样品的浓度高于 161.9mg/100g。因此，所得到的结果表明，（大部分被低估的）成熟酸凝乳奶酪的生物胺水平相当可接受，尽管在个别样品中确实观察到了部分异常高的浓度（>250mg/100g）。
