Faculty of Food and Biochemical Technology, Department of Food Analysis and Nutrition, University of Chemistry and Technology, Technicka 3, Prague 6, 166 28, Prague, Czech Republic.
Czech Agriculture and Food Inspection Authority, Za Opravnou 6, 150 00, Prague 5, Prague, Czech Republic.
Anal Bioanal Chem. 2022 Sep;414(23):6825-6840. doi: 10.1007/s00216-022-04246-6. Epub 2022 Aug 15.
To assess chocolate quality and authenticity comprehensively, a combination of various analytical procedures is involved, thereby making the process time-consuming and costly. Thus, we investigated the potential of ultra-high performance supercritical fluid chromatography coupled to quadrupole-time of flight mass spectrometry (UHPSFC-QTOF-MS) as an alternative to "classic" methods. By combining hexane and aqueous extracts from sequential extraction, a single 8-min analytical run enabled us (i) to determine cocoa butter equivalents (CBEs) and milk fat content based on the detection of selected triacylglycerols, (ii) to calculate dry non-fat cocoa solids based on determined theobromine and caffeine content, and (iii) to profile contained sugars. To obtain the most comprehensive information about sample composition, the MS method comprised a full MS scan for non-target screening and several time-scheduled targeted MS/MS functions ("parallel reaction monitoring") optimized according to the possible concentration ranges of the analytes. For 40 different chocolate samples, our results and those obtained by using standard methods (LC-UV for non-fat cocoa solids, and GC-FID for CBEs) were in good agreement. Compared to the conventional approach for chocolate quality and authenticity control, the presented SFC-MS method is a fast, cost-effective, and efficient alternative, and only samples suspicious for the presence of CBE should be referred to the standard GC-FID method for exact CBE quantification. In the study, also some challenges offered by SFC-MS have been addressed.
为了全面评估巧克力的质量和真实性，需要结合使用各种分析程序，这使得过程既耗时又昂贵。因此，我们研究了超高效超临界流体色谱与四极杆飞行时间质谱联用（UHPSFC-QTOF-MS）作为“经典”方法替代方法的潜力。通过将来自顺序提取的正己烷和水提取物结合在一起，单次 8 分钟的分析运行使我们能够：(i) 基于选定的三酰基甘油的检测来确定可可脂当量（CBE）和乳脂肪含量，(ii) 基于测定的可可碱和咖啡因含量来计算干燥的无脂可可固体，以及 (iii) 分析所含的糖。为了获得有关样品组成的最全面信息，MS 方法包括全 MS 扫描进行非靶向筛选和根据分析物的可能浓度范围优化的几个定时靶向 MS/MS 功能（“平行反应监测”）。对于 40 种不同的巧克力样品，我们的结果与使用标准方法（LC-UV 用于非脂可可固体，GC-FID 用于 CBE）获得的结果非常吻合。与用于巧克力质量和真实性控制的传统方法相比，所提出的 SFC-MS 方法是一种快速、具有成本效益且高效的替代方法，只有那些疑似存在 CBE 的样品才需要参考标准 GC-FID 方法进行精确的 CBE 定量。在研究中，还解决了 SFC-MS 带来的一些挑战。
