Vernhet Aude, Carrillo Stéphanie, Rattier Anaïs, Verbaere Arnaud, Cheynier Véronique, Nguela Julie Mekoue
SPO, University Montpellier, INRAE, Montpellier SupAgro, 34060 Montpellier, France.
Lallemand, SAS, 19 rue des Briquetiers, BP 59, 31 702 Blagnac, France.
J Agric Food Chem. 2020 Mar 18;68(11):3615-3625. doi: 10.1021/acs.jafc.0c00413. Epub 2020 Mar 3.
UV-visible spectrophotometry, size exclusion chromatography, and UHPLC-QqQ-MS were combined to evaluate the respective impacts of chemical changes and adsorption by yeasts on both proanthocyanidins (PA) and anthocyanins during the fermentation of a thermovinified red must by four yeast strains. Results evidenced a sharp decrease in anthocyanins (∼45%) and color intensity (∼50%), along with the formation of pyranoanthocyanins and flavanol-anthocyanin dimers related to yeast metabolism. However, the latter only accounted for 10% of anthocyanin losses. Comparison of spectrophotometry and phloroglucinolysis data underlined the involvement of PAs in chemical changes, related to yeast metabolites but also to direct reactions. Color losses during fermentation in this case study were mostly related to the formation of colorless compounds and to a decrease of copigmentation. Adsorption represented only a small proportion of pigment losses (∼5%) but a major part of those corresponding to total oligomeric/polymeric species, which were specifically involved. Only small differences could be evidenced between the four studied strains.
采用紫外可见分光光度法、尺寸排阻色谱法和超高效液相色谱-串联四极杆质谱法，评估了4种酵母菌株对热浸渍红葡萄汁进行发酵时，化学变化和酵母吸附作用对原花青素（PA）和花色苷的各自影响。结果表明，花色苷（约45%）和颜色强度（约50%）急剧下降，同时形成了与酵母代谢相关的吡喃花色苷和黄烷醇-花色苷二聚体。然而，后者仅占花色苷损失的10%。分光光度法和间苯三酚解聚数据的比较强调了PA在化学变化中的作用，这与酵母代谢产物有关，也与直接反应有关。在本案例研究中，发酵过程中的颜色损失主要与无色化合物的形成和共色作用的降低有关。吸附仅占色素损失的一小部分（约5%），但却是与总寡聚/聚合物种相应损失的主要部分，这些物种受到了特别影响。在所研究的4种菌株之间仅能证明存在微小差异。
