Chair of Food Chemistry and Molecular Sensory Science, TUM School of Life Sciences, Technical University of Munich, Lise-Meitner-Strasse 34, D-85354 Freising Germany.
Leibniz Institute for Food Systems Biology at the Technical University of Munich, Lise-Meitner-Strasse 34, D-85354 Freising Germany.
J Agric Food Chem. 2023 Nov 29;71(47):18466-18477. doi: 10.1021/acs.jafc.3c04015. Epub 2023 Nov 16.
The aroma of red wine is suggested to be influenced by interactions with nonvolatile polymers. To investigate this aroma binding effect in red wine, the key aroma compounds of a Primitivo red wine were quantified using GC-MS and an aroma recombinant with 27 odorants was prepared. In sensory experiments, an overall strong effect on the odor perception of the aroma recombinant was observed when high-molecular-weight (HMW) polymers of Primitivo red wine were added. An H NMR-based approach was developed to get an insight into the molecular mechanisms of this aroma binding effect in red wine. Evaluation of qualitative changes in the NMR spectra and quantitative time-dependent measurements revealed a clear distinction between different molecular interaction types: (i) no interactions for esters, alcohols, furanones, ketones, and C-norisoprenoids, (ii, iii) noncovalent interactions for acids, aldehydes, and lactones, and (iv) π-π interactions for pyrazines and phenols. Additionally, the influence of the molecular weight of polymers was evaluated, where the HMW fraction 30-50 kDa showed the highest interaction activity, for example for π-π interactions. Based on these results, the new approach allowed the direct analysis of noncovalent interactions between odorants and HMW polymers and therefore allowed for the first time the description of the aroma binding effect on a molecular basis.
红葡萄酒的香气被认为受到与非挥发性聚合物相互作用的影响。为了研究红葡萄酒中的这种香气结合效应，使用 GC-MS 对普里米蒂沃红葡萄酒的关键香气化合物进行了定量，并制备了含有 27 种气味的香气重组体。在感官实验中，当添加普里米蒂沃红葡萄酒的高分子量（HMW）聚合物时，观察到对香气重组体气味感知的整体强烈影响。基于 1H NMR 的方法被开发出来，以深入了解红葡萄酒中这种香气结合效应的分子机制。对 NMR 光谱的定性变化和定量随时间变化的测量的评估揭示了不同分子相互作用类型之间的明显区别：（i）酯、醇、糠醛、酮和 C-非异戊二烯类无相互作用，（ii、iii）酸、醛和内酯为非共价相互作用，（iv）吡嗪和酚类为π-π相互作用。此外，还评估了聚合物分子量的影响，其中 30-50 kDa 的 HMW 级分显示出最高的相互作用活性，例如对于 π-π 相互作用。基于这些结果，该新方法允许直接分析气味化合物与 HMW 聚合物之间的非共价相互作用，从而首次能够在分子基础上描述香气结合效应。
