The effect of fruit processing and enzymatic treatments on pomegranate juice composition, antioxidant activity and polyphenols content

Abstract Pomegranate fruit and pomegranate juices have recently received great attention for their health benefits, mainly due to their high polyphenols content and the related antioxidant capacity. Nevertheless, the pomegranate processing and its effects on juice composition has been only little investigated. In this paper two important steps of pomegranate juice production, the separation of arils from peels (cleaning) and the enzymatic clarification of the juice, were considered, and the characterization (pH, acidity, total soluble solids, protein, polyphenols and antioxidant activity) of pomegranate juices obtained in different cleaning and clarification conditions was reported. Results showed that the cleaning procedures largely affect the juice composition and its organoleptic properties, and a significant positive correlation was found among peels content before pressing, total polyphenols, antioxidant capacity and perceived bitterness of the juice. Juice with endocarp and mesocarp content of 2 and 10 g/100 g and only mesocarp of 10 g/100 g showed a TEAC value of 14.1 and 13.1 mmol/L, respectively, significantly higher compared to juice with no peels (9.5 mmol/L). Treatment with pectolytic enzymes resulted in a better extraction of all the fruit components, as polyphenols (about 2-fold) and a decrease of turbidity (−40%).