Boido Eduardo, Lloret Adriana, Medina Karina, Carrau Francisco, Dellacassa Eduardo
Seccion Enologia, Facultad de Quimica, Universidad de la Republica, Gral. Flores 2124, 11800-Montevideo, Uruguay.
J Agric Food Chem. 2002 Apr 10;50(8):2344-9. doi: 10.1021/jf0109367.
Under traditional wine-making conditions, this work examines the beta-glycosidic activity of Oenococcus oeni on glycosylated aroma compounds of Tannat wines during malolactic fermentation (MLF) by comparing the changes on selected aglycones liberated. MLF diminished the content of all the glycosylated compounds. The level of the free aroma components was slightly modified by the action of the malolactic fermentation so that the cleavage of the glycosidic linkage by the beta-glycosidic activity of O. oeni did not appear to increase significatively the aglycone contents. The consequences of further chemical rearrangements of the algycones under wine conditions were explored using synthesized glycoconjugates on synthetic medium. Bacteria could also be responsible for the cleavage of aroma glycosylated compounds, being the aglycone adsorbed on polysaccharides or peptidoglycans and was released into the external medium. This hypothesis was studied through the evaluation of a stable arrangement of aroma compounds with polysaccharides produced by lactic acid bacteria. A possible retaining of free-made aroma compounds into the whole cells of O. oeni was also investigated through cell culture analysis. Through the results obtained, we assume stable linkage of aroma compounds with bacterial polysaccharides.
在传统酿酒条件下，本研究通过比较所选游离苷元的变化，考察了乳酸乳球菌在丹那特葡萄酒糖基化香气化合物苹果酸-乳酸发酵（MLF）过程中的β-糖苷活性。MLF降低了所有糖基化化合物的含量。苹果酸-乳酸发酵的作用使游离香气成分的水平略有改变，因此乳酸乳球菌的β-糖苷活性对糖苷键的裂解似乎并未显著增加苷元含量。使用合成糖缀合物在合成培养基上探索了葡萄酒条件下苷元进一步化学重排的后果。细菌也可能导致香气糖基化化合物的裂解，苷元被吸附在多糖或肽聚糖上并释放到外部培养基中。通过评估乳酸菌产生的多糖与香气化合物的稳定排列来研究这一假设。还通过细胞培养分析研究了游离产生的香气化合物在乳酸乳球菌全细胞中的可能保留情况。根据所得结果，我们推测香气化合物与细菌多糖之间存在稳定的联系。
