Synergistic effects of Pectinex Ultra Clear and Lallzyme Beta on yield and bioactive compounds extraction of Concord grape juice

In this work, the synergistic effects of the combination of Pectinex Ultra Clear (PUC), presenting high pectinase activity, and Lallzyme Beta (LB), presenting cellulase activity were tested for grape juice extraction from Vitis labrusca L. variety Concord. The variables time, temperature, enzyme concentration and PUC/LB ratio were analyzed with the responses juice yield and reducing capacity. PUC improved the juice yield while LB increased the reducing capacity. However, the mix PUC/LB provided an increase in juice yield and reducing capacity, reaching to 75.8% and 1090 mg L-1, respectively. The best conditions for grape juice extraction were: 51 degrees C, 52 min, 0.75 U g(-1) and PUC/LB ratio 0.52. Twenty-three phenolic compounds were identified and quantified by HPLC-DAD-MS, where the content of quercetin 3-O-glucoside and total anthocyanins were improved up to 112% and 41%, respectively, using enzymes. The mix of two enzymatic preparations improved the juice yield and bioactive compounds extraction when compared with each preparation individually. The adequate choice of enzymatic preparation and the extraction conditions are very important in the juice yield and quality for food industries. (C) 2016 Elsevier Ltd. All rights reserved.