Effect on Merlot red wine of fining agents mixture: application of the simplex centroid design

Abstract In the elaboration of young red wine, it is necessary to obtain a clear product with stable color. The clarity and stability can be obtained using fining agents. The objective of this study was to evaluate the combined effect of fining with pea protein isolate (PPI), bentonite, and polyvinylpyrrolidone (PVPP) on a red wine, using the experimental design of mixtures. Merlot wine was used to evaluate the changes on monomeric flavan-3-ol, turbidity and anthocyanin levels promoted by the fining compounds. For all the parameters, the adjusted models showed influence of the combination of the three fining agents. Together, bentonite and PVPP have synergistic effect on the reduction in monomeric flavanol levels. Such synergistic effect was also observed with PPI and PVPP combination for the reduction in turbidity. However, for this same characteristic (turbidity), the combination of PPI and bentonite has antagonistic effect. To achieve broader wine fining objectives, the simultaneous optimization of the three response variables demonstrated the importance of the presence of the three refining agents in the following proportions: 25% PPI, 43% PVPP and 32% Bentonite. The isolated use of these additives would not result in the same effect on the three studied variables.

摘要 在年轻红葡萄酒的酿造过程中，需获得澄清度良好且色泽稳定的成品。借助澄清剂即可实现上述澄清与色泽稳定效果。本研究采用混料实验设计，探究豌豆分离蛋白（pea protein isolate, PPI）、膨润土（bentonite）与聚乙烯吡咯烷酮（polyvinylpyrrolidone, PVPP）三种澄清剂复配使用对红葡萄酒的影响效果。本研究以梅洛葡萄酒为试材，分析三类澄清剂对单体黄烷-3-醇、浊度及花青素含量的调控变化。针对所有检测指标，经校正后的模型均显示三种澄清剂的复配组合对其存在显著影响。膨润土与PVPP复配使用时，对单体黄烷醇含量的降低具有协同效应；PPI与PVPP复配时，在降低浊度方面同样表现出协同效应。但针对浊度这一指标，PPI与膨润土复配时则呈现拮抗效应。为实现更全面的葡萄酒澄清目标，通过对三个响应变量进行同步优化，结果表明三种澄清剂需按以下比例复配方可达到最佳效果：25% PPI、43% PVPP及32% 膨润土。若单独使用上述助剂，则无法对三个研究变量产生同等的影响效果。