Jaromír Veverka

Influence of Technological Processes on Biologically Active Compounds of Produced Grapes Juices

Grape juice quality can be substantially influenced by different processing methods and their parameters. This study deals with the influence of thermomaceration temperature and its holding time on important juice quality parameters such as the content of trans-resveratrol, trans-piceid, trans-ε-viniferin, and 2,4,6-trihydroxyphenantrene-2-O-glucoside. All the aforementioned compounds together with antioxidative capacity, total polyphenols, and antimutagenic activity were measured. This study used the following grapes: Blaufränkisch, Blaufränkisch bio, Saint Laurent, Grüner Veltliner, Grüner Veltliner bio, and Müller-Thurgau. For all tested grape varieties, the most important processing parameters were temperature and thermomaceration holding time. There were no significant differences in the content of the studied compounds. Three preservation technologies, freezing, bottle pasteurization, and high-pressure treatment, were also studied regarding the content of abovementioned biologically active compounds. Results of this study can be immediately applied to grape juice production.