Aisala Heikki, Sinkkonen Jari, Kalpio Marika, Sandell Mari, This Hervé, Hopia Anu
Food Chemistry and Food Development, Department of Biochemistry, University of Turku, FI-20014 Turku, Finland; Functional Foods Forum, University of Turku, FI 20014 Turku, Finland.
Instrument Centre, Department of Chemistry, University of Turku, Turku, FI-20014 Finland.
Talanta. 2016 Dec 1;161:245-252. doi: 10.1016/j.talanta.2016.08.056. Epub 2016 Aug 19.
A direct quantitative proton nuclear magnetic resonance spectroscopy method was developed for the measurement of saccharides, organic acids and amino acids in potato (Solanum tuberosum L.) tuber filaments, a complex gel-like food matrix. The method requires minimal sample preparation. It is thus a faster alternative compared to liquid sample matrices, as well as an extension to methods analyzing only selected metabolites in the sample. The samples in this study were either raw or steamed potato strips that were either measured as DO extracts or directly without extraction or derivatization steps (in situ technique). A total of 22 compounds were identified in extracts and 18 in potato strips. Of these, 20 compounds were quantifiable in potato extracts and 13 compounds in potato strips. The effect of thermal processing was reflected in the profile of analyzed compounds. One example was fumaric acid, which was completely lost in steamed samples in both measurement techniques. Additionally, the content of γ-aminobutyric acid in steamed potato strips was lower. In potato extracts, the contents of additional 7 compounds were statistically different. The raw and steamed samples separated into two groups with multivariate models both in extracts and potato strips, and these groups were linked to changes in aforementioned compounds. These results demonstrated that the in situ quantitative H NMR technique is a useful tool to analyze potato metabolites. This technique could be further applied to any gel-like complex matrix, meaning that lengthy sample pretreatment could be skipped.
开发了一种直接定量质子核磁共振光谱法，用于测量马铃薯（Solanum tuberosum L.）块茎细丝中的糖类、有机酸和氨基酸，马铃薯块茎细丝是一种复杂的凝胶状食物基质。该方法所需的样品制备最少。因此，与液体样品基质相比，它是一种更快的替代方法，也是对仅分析样品中选定代谢物的方法的扩展。本研究中的样品是生的或蒸过的马铃薯条，要么作为DO提取物进行测量，要么直接进行测量，无需提取或衍生步骤（原位技术）。在提取物中总共鉴定出22种化合物，在马铃薯条中鉴定出18种。其中，20种化合物在马铃薯提取物中可定量，13种化合物在马铃薯条中可定量。热加工的影响反映在分析化合物的谱图中。一个例子是富马酸，在两种测量技术中，它在蒸过的样品中完全消失。此外，蒸过的马铃薯条中γ-氨基丁酸的含量较低。在马铃薯提取物中，另外7种化合物的含量有统计学差异。生样品和蒸过的样品在提取物和马铃薯条中都通过多变量模型分为两组，这些组与上述化合物的变化有关。这些结果表明，原位定量核磁共振技术是分析马铃薯代谢物的有用工具。该技术可进一步应用于任何凝胶状复杂基质，这意味着可以跳过冗长的样品预处理。
