Effect of the black chokeberry (Aronia melanocarpa (Michx.) Elliott) juice acquisition method on the content of polyphenols and antioxidant activity.

The primary objective of the study was to determine the effect of process conditions on extraction efficiency and the total amount of released polyphenols and antioxidant activity (AA) in black chokeberry juice. The study samples were fruits of black chokeberry (Aronia melanocarpa (Michx.) Elliott) cv. Galicjanka. In the study, two kinds of presses-piston press and twin gear juice extractor-were used, and two raw material pretreatment methods-freezing and thawing and enzymatic liquefaction-were applied. The study showed that pressing efficiency depends on the design of press and the nature of pretreatment. The highest pressing efficiency was obtained using the twin gear juice extractor. Enzymatic liquefaction of shredded fruits significantly increased the efficiency of pressing by the piston press. The type of press and the pretreatment method used had an effect on the quality traits of the extracted juices. The highest content of soluble solids was obtained for fruits not subjected to any pretreatment and pressed using the twin gear press. The highest total phenolic content was obtained in juice extracted using the piston press from shredded fruits subjected to enzymatic treatment at 45°C. A higher total phenolic content was also a characteristic of juice obtained from fruits not subjected to any pretreatment and extracted using the twin gear press. The capacity of the black chokeberry juices for free radical quenching oscillated around the level of approximately 90%. The study showed that the application of suitable processing methods is necessary for the acquisition of products with desirable quality traits.