Influence Of Age On Red Wine Colour During Fining With Bentonite And Gelatin

Abstract

Two fining agents (bentonite and gelatin) have contributed to the reduction of colour of Pinot Noir wine of different ages. Bentonite caused more significant changes in the colour of young wines. Colour intensity, coloured anthocyanin forms, and polymers were reduced to a greater extent, while colourless anthocyanins and total phenolic substances were reduced to a lower extent. Smaller changes in coloured substances resulted from wine treatment with gelatin. The intensity of the share of yellow colour decreased and the intensity of the share of red colour, together with dA% value, increased. The influence of bentonite on the colour of the wine decreased while the influence of gelatin increased with wine ageing.

Effects of fining with different bentonite labels and doses on colloidal stability and colour of a Valpolicella red wine

“…() on wines with 2‐month age. Similar results were observed in red wines aged for a longer period of time (Stankovic et al ., ) than the Valpolicella wine under study. Differently to our results (Table ), Tománková et al .…”

“…Likewise to what reported by Stankovic et al . (), Tománková et al . () found that the addition of 1.00 g L −1 bentonite was necessary to reduce anthocyanins by 23–26%.…”

“…These results partially contradicted what was outlined by Stankovic et al . () who observed that bentonite influenced the concentration of total phenol compounds, such as tannin substances, especially with a dose of 1.0 g L −1 . Unfortunately, no indication on bentonite characteristic was given in their study.…”

“…Moreover, bentonite may bind large phenolic compounds, such as anthocyanins, and may also bind phenolic compounds complexed with proteins (Salazar et al ., ; Stankovic et al ., ). As a consequence, the bentonite treatment can modify both the concentration and composition of phenolic compounds and affect the colour intensity and hue of red wines (Stankovic et al ., ; Tománková et al ., ; González‐Neves et al ., ).…”

“…Due to these reasons, the use of bentonite on red wines has always been disheartened, despite the use of clays with such characteristics as to restrict the removal of phenolic by promoting that of unstable proteins may be certainly beneficial. Previous research on the effects of bentonite on red wine composition mainly considered its impact on phenolic compounds (Salazar et al ., ), colour properties (Tománková et al ., ), antioxidant capacity (Yildirim, ) and colour change during fining as affected by the red wine age (Stankovic et al ., ). The fining effects of bentonite on colloidal stability, phenolic substances and colour of red wine are not fully studied (Balík, ; Iturmendi et al ., ; Yildirim, ), and no other previous investigation was carried out on the relationship between bentonite dose, bentonite characteristic and colloidal stability of a red wine.…”