Impact of Commercial Preparations of Pectinases on the Chemical Composition and Stability of Phenolic Compounds in Grape Juices

Enzymatic preparations in juice processing come in different formulations, but their enzymatic activities on the stability of this beverage must be studied. This study evaluated five commercial yield and color extraction preparations concerning the chemical composition of grape juice, color, and phytochemicals quantified in HPLC. The activity of the enzymes was evaluated, and a study of the stability of the juices over 360 days was carried out. The color extraction enzymes Everzym Thermo and Endozym Rouge (hemicellulases) increased the content of flavonoids, especially malvidin-3-glucoside. The Endozym Pectofruit PR preparation (pectin lyase) stood out for its yield and extraction of organic acids such as tartaric. When assessing the stability of the juice using the half-life parameter, it became clear that all the juices showed similar evolutionary behavior, with more accelerated degradation of the components related to color in the first 100 days. Even though the Everzym Thermo preparation showed greater color extraction, it had higher degradation rates for these parameters and anthocyanins than the other preparations evaluated. At the end of the storage period, the differences in color and anthocyanins were small between the preparations, practically equal to the control. This shows that in the juice obtained without enzymes, the nondegradation of polysaccharides may be associated with a protective effect on color and anthocyanins.