Effect of the time of cold maceration on the evolution of phenolic compounds and colour of Syrah wines elaborated in warm climate

The effect of different cold maceration times on Syrah red wines from warm climate has been evaluated. Differential colorimetry and tristimulus colorimetry were applied to colour data at different points of the vinification stage. Virtually, all the phenolic compounds showed significantly higher content in cold macerated wines, even more when longer contact time was used. Long cold macerated (LCM) wines had the significantly (P < 0.05) highest chroma values (C*ab) and lowest of lightness (L*) and hue (hab). Unexpectedly, wines submitted to short-time cold maceration (SCM) presented the lowest chroma values, even significantly inferior to that observed in traditional macerated (TM) wines. Moreover, colour changes (DE*ab) between TM and SCM were mainly quantitative (%D2L and %D2C), whereas they were also qualitative when compared TM with LCM (%D2C and %D2H). Cold maceration in warm climates characterised by common colour losses must be carefully employed because undesirable consequences on colour may occur.