Department für Chemie, Lehrstuhl für Lebensmittelchemie , Technische Universität München , Lise-Meitner-Straße 34 , D-85354 Freising , Germany.
Deutsche Forschungsanstalt für Lebensmittelchemie Lise-Meitner-Straße 34 , D-85354 Freising , Germany.
J Agric Food Chem. 2018 Mar 21;66(11):3038-3045. doi: 10.1021/acs.jafc.8b00180. Epub 2018 Mar 6.
A large set of volatiles (a metabolome) was isolated by SAFE distillation from 25 high priced rums prepared from sugar cane juice (SCJ) and 26 high priced rums manufactured from sugar cane molasses (SCM). The volatile fractions were first analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOF-MS), and the "comprehensive template matching fingerprinting" was used to extract the entire features present in the respective set of volatile compounds. After raw data pretreatment, chemometrics was used to locate marker compounds. Following, a sparse-partial-least-squares discriminant analysis ( sPLS-DA) and a partial-least-squares discriminant analysis (PLS-DA) were applied to a training data set for creating a model. The model was validated using leave-one-out cross validation and tested over an independent data set to evaluate its predictive power. The characteristic fingerprint resulted in a 100% correct classification of sugar cane juice rums, thus achieving the first aim of locating markers for these higher quality rums. Then, past-processing identification within the discriminant features was done to characterize 12 significant marker compounds as 1-decanol, γ-dodecalactone, ethyl 3-methylbutanoate, ethyl nonanoate, 3-furancarboxaldehyde, 1-hexanol, β-ionone, 2- and 3-methylbutanol, methyl decanoate, 3-octanol, and 2-undecanone. Quantitation of eight selected markers by stable isotope dilution assays confirmed higher concentrations in SCJ compared to SCM and served as the final proof to differentiate both types of spirits.
采用 SAFE 蒸馏法从 25 种由甘蔗汁（SCJ）制成的高价朗姆酒和 26 种由甘蔗糖蜜（SCM）制成的高价朗姆酒中分离出大量挥发性物质（代谢组）。首先通过全二维气相色谱飞行时间质谱（GC×GC-TOF-MS）对挥发性馏分进行分析，并采用“综合模板匹配指纹图谱”提取各自挥发性化合物集中存在的所有特征。在对原始数据进行预处理后，使用化学计量学定位标记化合物。然后，对训练数据集应用稀疏偏最小二乘判别分析（sPLS-DA）和偏最小二乘判别分析（PLS-DA）建立模型。使用留一法交叉验证对模型进行验证，并在独立数据集上进行测试以评估其预测能力。特征指纹图谱可实现对甘蔗汁朗姆酒的 100%正确分类，从而实现定位这些高品质朗姆酒标记物的第一个目标。然后，在判别特征中进行过去加工识别，将 12 种重要标记化合物表征为 1-癸醇、γ-十二内酯、乙基 3-甲基丁酸酯、乙基壬酸酯、3-糠醛、1-己醇、β-紫罗兰酮、2-和 3-甲基丁醇、甲基癸酸酯、3-辛醇和 2-十一酮。通过稳定同位素稀释测定法对 8 种选定标记物进行定量，证实了 SCJ 中的浓度高于 SCM，这是区分两种类型烈酒的最终证据。
