Effect of fining with new plant proteins on the aroma composition, phenolic compounds, and color of a Monastrell wine

Abstract

The wine industry has increased its interest in finding new fining agents, and vegetable proteins have received increasing attention. Quinoa and kiwicha are native pseudocereals to the Andean highlands with high protein content and are considered gluten-free products. This work aimed to determine the effect of fining with quinoa and kiwicha protein extracts (QP and KP respectively) at different doses (30 and 50 g/hL) on the aroma composition, color, and phenolics of a Monastrell wine compared to pea proteins and gelatin. Fining treatments produced no significant reduction of TPI. Except for QP at 30 g/hL and the lowest dose of pea proteins, the fining treatments decreased the content of total anthocyanins. The doses of 50 g/hL of QP and KP were particularly efficient, producing the largest decrease in total tannins. Analyses by size exclusion chromatography showed that treatments with QP and KP were capable of selectively removing high molecular weight phenolics. All fining agents slightly decreased the color intensity. All fining treatments showed a significant decline in total ester concentration (26-45%). Instead, total alcohols remained constant upon the fining treatments. Five terpenes were identified in all wines, and their content was not affected by the fining treatments.