Impact of plant-based fining agents on phenolic compounds and sensory characteristics of Cabernet Sauvignon red wines.

Abstract

Fining and stabilization of wine result from physical-chemical processes that promote the sedimentation of unstable compounds. These can be optimized using fining agents, such as proteins which are known for their effectiveness in reducing turbidity and modulating sensory attributes, although in young red wines they can cause color loss. In recent years, plant proteins from cereals, legumes, or potatoes have gained relevance as sustainable alternatives suitable for vegan consumers. The impact of different plant-based fining agents on the phenolic composition, color, and sensory profile of Cabernet sauvignon wines was evaluated under two winemaking conditions: A, a traditional vinification with 14 days of maceration, and B, a vinification including 40% whole-cluster addition and 21 days of maceration. Five treatments were applied: control, pea protein (A), chitin (Q), pea + chitin (AQ), and yeast protein (L), in a completely randomized design with three replicates. Chemical parameters, phenolic compounds, CIELAB color, and RATA sensory analysis were determined. Principal component analysis showed that, in vinification A, the yeast protein treatment exhibited the highest color intensity, followed by AQ. In vinification B, AQ displayed higher concentrations of tannins and phenolics; compounds extracted from the stems were not removed during fining. No significant differences were detected in basic chemical parameters. Sensory evaluation indicated that wines from trial B treated with A or AQ were perceived as more astringent and acid, whereas yeast protein was associated with greater mouthfeel and, in the absence of stems, with higher color intensity. The AQ treatment without stems stood out for its high color intensity and violet hue, attributes favorable in young wines.