Some effects of processing enzymes on anthocyanins and phenolics in Pinot noir and Cabernet Sauvignon wines

Pinot noir and Cabernet Sauvignon wines were made using four commercial enzyme preparations along with controls. Total monomeric anthocyanin and individual pigments changes were monitored throughout winemaking and storage using spectrophotometric and HPLC methods. A complete phenolic profile of the wines was determined at the completion of fermentation by HPLC. Three of the enzyme treated Pinot noir wines contained significantly less total monomeric anthocyanin than control (p < 0.05) and decreased amounts of the major pigment, malvidin-3-glucoside. Pigment changes were less pronounced in the Cabernet Sauvignon wines as compared to Pinot noir. Two enzyme treated Cabernet Sauvignon wines contained less (p < 0.05) malvidin-3-glucoside, 3-glucosylacetate, and 3-glucosylcoumarate, than did the control. One of the enzymes appeared to hydrolyze quercetin glucuronide with a concomitant rise in the aglycon. trans-Resveratrol content increased in all enzyme treated wines and those that had the greatest resveratrol content also contained the greatest quantity of quercetin aglycon. Enzymes appeared to contain varying degrees of an esterase activity as shown by the cleavage of tartaric acid from caffeoyl tartrate to form caffeic acid. These activities occurred in both Cabernet Sauvignon and Pinot noir.