Some oligopeptides can impart kokumi flavor to foods and beverages, a topic still not addressed in wine. A targeted ultra-high performance liquid-chromatography-mass spectrometry (UHPLC-MS/MS) metabolomics method capable of quantifying both amino acids and oligopeptides in wines was therefore developed and validated, confirming the presence of 50 oligopeptides in wine, most of which had been previously unexplored. In silico screening of the affinity of these oligopeptides to interact with CaSR, the protein necessary to activate kokumi sensations, highlighted 8 dipeptides and 3 tripeptides as putative kokumi compounds. These compounds were ubiquitous in a representative set of Trentodoc classic method sparkling wines, with an average concentration of kokumi oligopeptides of 19.8 mg/L, ranging between 9.1 and 33.3 mg/L. Half of the sparkling wine samples also contained glutamic acid at concentrations equal to or greater than the threshold for the umami taste in wine, namely, 48 mg/L. Sensory tests on the dipeptide Gly-Val confirmed the ability of this novel kokumi compound to significantly modify the perception of complex real wine matrices but not of the simple model one. Preliminary laboratory-scale fermentation tests showed that the oligopeptide profile in wines is linked to the starting grape matrix and that the patterns change by fermenting barley or apple juice with the same yeast.

中文翻译：

---

使用 UHPLC-ESI-MS/MS 靶向方案探索经典起泡酒中推定的 Kokumi 寡肽


一些寡肽可以赋予食品和饮料浓味，这是葡萄酒中仍未涉及的话题。因此，开发并验证了一种能够定量葡萄酒中氨基酸和寡肽的靶向超高效液相色谱-质谱 （UHPLC-MS/MS） 代谢组学方法，证实了葡萄酒中存在 50 种寡肽，其中大多数以前未曾探索过。在计算机筛选中，这些寡肽与 CaSR（激活 kokumi 感觉所必需的蛋白质）相互作用的亲和力突出了 8 个二肽和 3 个三肽作为推定的 kokumi 化合物。这些化合物在一组具有代表性的 Trentodoc 经典方法起泡酒中无处不在，kokumi 寡肽的平均浓度为 19.8 mg/L，范围在 9.1 至 33.3 mg/L 之间。一半的起泡酒样品还含有谷氨酸，其浓度等于或大于葡萄酒鲜味的阈值， 即 48 mg/L。对二肽 Gly-Val 的感官测试证实了这种新型 kokumi 化合物能够显着改变对复杂真实葡萄酒基质的感知，但不能改变对简单模型基质的感知。初步的实验室规模发酵测试表明，葡萄酒中的寡肽谱与起始葡萄基质有关，并且通过用相同的酵母发酵大麦或苹果汁来改变模式。