Reserve Ruby Port wine: alternatives to gelatine protein fining agents

Animal protein fining agents are traditionally used in the wine industry. However, in recent years some allergic problems of these protein fining agents have promoted to search for allergen free alternatives. A possible alternative to animal proteins are plant proteins, in particular, pea protein. Therefore, the aim of this study was to compare the effect of gelatine of animal origin (porcine gelatine and fish skin gelatine) with non-allergenic fining agents (association of PVPP, plant protein and silica; pea protein; association of PVPP, calcium bentonite and inert yeast; inert yeast and activated sodium bentonite) on a Reserve Ruby Port Wine chromatic characteristics, phenolic compounds and sensory attributes, at laboratory scale. Colour intensity, hue, coloured anthocyanins and polymeric pigments showed a significant decrease in all fined wines when compared to the unfined wine. The highest decrease in colour intensity, total anthocyanins and polymeric pigments occurred in wines treated with porcine gelatine. The lowest decrease in colour intensity was observed in wines treated with inert yeast, association of PVPP, calcium bentonite and inert yeast and activated sodium bentonite. The most balanced wine and that with the best results on colour intensity was the one treated with association of PVPP, calcium bentonite and inert yeast.This work was partially funded by the Chemical Research Center (CQ-UTAD). Additional thanks to SOGRAPE for the availability of wines and to the Projet I&D INNOVINE&WINE – Vineyard and Wine Innovation Platform, NORTE-01-0145-FEDER-000038, co-financed by the Fundo Europeu de Desenvolvimento Regional (FEDER) through the NORTE 2020 (Programa Operacional Regional do Norte 2014/2020)