Effect of a cold-active pectinolytic system on colour development of Malbec red wines elaborated at low temperature

The effect of a new cold-active pectinolytic system on colour of Malbec wines was studied under the following winemaking conditions: (i) fermentation at low temperature (20 degrees C) and (ii) prefermentative cold maceration (PCM) (5 degrees C-7 days) followed by traditional fermentation (28 degrees C). The pectinolytic system was mainly composed of polymethylgalacturonase and pectin lyase activities, detected under similar conditions to those in winemaking (pH 3.6-20 degrees C). The results show that the enzyme system significantly accelerated colour extraction by reducing the maceration time necessary for vinification at low temperature and shortening the PCM stage. Enzyme-treated wines exhibited better chromatic parameters than their controls at devatting and after 6 months of storage. The cold-active enzyme compensated the decrease in colour extraction due to the low maceration temperature, achieving high-quality wines with chromatic characteristics similar to those of traditional wines.