Characterisation of Colour Components and Polymeric Pigments of Commercial Red Wines by Using Selected UV-Vis Spectrophotometric Methods

The composition of the colour components of commercial red wines from Italy was analysed in terms of total colour,co-pigmentation, SO2-resistant pigments, small and large polymeric pigments, and tannins. A total of 128 wines,including Sangiovese, Cabernet Sauvignon, Nero d’Avola, Merlot, Marzemino, Negroamaro, Aglianico, Cannonauand Rossese di dolceacqua from five vintages (1999 to 2003) were analysed. The composition of the wines showedsignificant differences in terms of total colour and co-pigmentation. Total colour at 520 nm was highest inMarzemino (7.50±1.5 AU, absorbance units), and then in Aglianico (7.10±2.8 AU) and Cabernet Sauvignon(5.01±2.50 AU). The level of large and small polymeric pigments in Sangiovese wines showed a range from 0.05 to0.40 and 0.10 to 0.27 AU 520 nm respectively. The variation in the level of polymeric pigments is affected by anumber of factors, including vintage, grape composition, fermentation and storage conditions

Characterisation of Colour Components and Polymeric Pigments of Commercial Red Wines by Using Selected UV-Vis Spectrophotometric Methods

The composition of the colour components of commercial red wines from Italy was analysed in terms of total colour, co-pigmentation, SO2-resistant pigments, small and large polymeric pigments, and tannins. A total of 128 wines, including Sangiovese, Cabernet Sauvignon, Nero d\u2019Avola, Merlot, Marzemino, Negroamaro, Aglianico, Cannonau and Rossese di dolceacqua from five vintages (1999 to 2003) were analysed. The composition of the wines showed significant differences in terms of total colour and co-pigmentation. Total colour at 520 nm was highest in Marzemino (7.50\ub11.5 AU, absorbance units), and then in Aglianico (7.10\ub12.8 AU) and Cabernet Sauvignon (5.01\ub12.50 AU). The level of large and small polymeric pigments in Sangiovese wines showed a range from 0.05 to 0.40 and 0.10 to 0.27 AU 520 nm respectively. The variation in the level of polymeric pigments is affected by a number of factors, including vintage, grape composition, fermentation and storage condition

Determination of grape quality at harvest using Fourier transform mid-infrared spectroscopy and multivariate analysis.

A rapid method for the simultaneous measurement of gluconic acid and glycerol, two important chemical markers of grape infection, was developed using Fourier-transform mid-infrared (FT-MIR) spectroscopy. The method used a combination of FT-MIR with partial-least squares (PLS) regression and compositional data of Trebbiano and Sangiovese grapes obtained with high performance ion-exchange chromatography (HPLC). A total of 320 grape samples were analyzed, including grapes hand picked in the vineyards (200 samples) and mechanically sampled from trucks upon arrival at the wineries (120 samples). Gluconic acid and glycerol increased with increasing percentage of grape infection assessed by visual inspection (r = 0.928). The best result was obtained for gluconic acid (R2 = 0.979; RMSECV = 0.63; RPD = 7.0),), indicating that FT-MIR was suitable for process control

Bio e biodinamico: un test sulle uve Sangiovese

Cresce la domanda di prodotti sani e naturali. Le prove condotte dimostrano che \ue8 possibile ottenere vini di qualit\ue0, migliorando anche tipicit\ue0 e gradevolezz