Millarini Valentina, Ignesti Simone, Cappelli Sara, Ferraro Giovanni, Adessi Alessandra, Zanoni Bruno, Fratini Emiliano, Domizio Paola
Department of Agriculture, Food, Environment and Forestry (DAGRI)-University of Florence, P.le delle Cascine 18, 50144 Florence, Italy.
Department of Chemistry "Ugo Schiff" and Center for Colloid and Surface Science (CSGI)-University of Florence, Via della Lastruccia 3-13, 50019 Sesto Fiorentino, Italy.
Foods. 2020 Oct 3;9(10):1407. doi: 10.3390/foods9101407.
Nowadays commercial preparations of yeast polysaccharides (PSs), in particular mannoproteins, are widely used for wine colloidal and tartrate salt stabilization. In this context, the industry has developed different processes for the isolation and purification of PSs from the cell wall of . This yeast releases limited amounts of mannoproteins in the growth medium, thus making their direct isolation from the culture broth not economically feasible. On the contrary, , a non- yeast isolated from wine, releases significant amounts of PSs during the alcoholic fermentation. In the present work, PSs released by were recovered from the growth medium by ultrafiltration and their impact on the wine colloidal stability was evaluated. Interestingly, these PSs contribute positively to the wine protein stability. The visible haziness of the heat-treated wine decreases as the concentration of added PSs increases. SDS-PAGE Gel electrophoresis results of the haze and of the supernatant after the heat stability test are consistent with the turbidity measurements. Moreover, particle size distributions of the heat-treated wines, as obtained by Dynamic Light Scattering (DLS), show a reduction in the average dimension of the protein aggregates as the concentration of added PSs increases.
如今，酵母多糖（PSs）的商业制剂，尤其是甘露糖蛋白，被广泛用于葡萄酒的胶体和酒石酸盐稳定。在此背景下，该行业已开发出不同方法从[酵母名称]的细胞壁中分离和纯化PSs。这种酵母在生长培养基中释放的甘露糖蛋白量有限，因此直接从培养液中分离它们在经济上不可行。相反，[另一种酵母名称]，一种从葡萄酒中分离出的非[第一种酵母名称]酵母，在酒精发酵过程中会释放大量的PSs。在本研究中，通过超滤从生长培养基中回收了[另一种酵母名称]释放的PSs，并评估了它们对葡萄酒胶体稳定性的影响。有趣的是，这些PSs对葡萄酒蛋白质稳定性有积极作用。随着添加PSs浓度的增加，热处理葡萄酒的可见浑浊度降低。热稳定性测试后浑浊物和上清液的SDS-PAGE凝胶电泳结果与浊度测量结果一致。此外，通过动态光散射（DLS）获得的热处理葡萄酒的粒度分布表明，随着添加PSs浓度的增加，蛋白质聚集体的平均尺寸减小。
