Antiradical-antimicrobial activity and phenolic profile of pomegranate (Punica granatum L.) juices from different cultivars: a comparative study

Abstract

Pomegranate juice (PJ) constituents have shown to exhibit anticarcinogenic, antimicrobial, antioxidant and antiviral activities. In the present study, the concentration of phenolic compounds and the antiradical activity of PJs from the fruits of the two relatively new Greek cultivars ``Persephone{''}and ``Porphiroyeneti{''}were determined in comparison to the ``Wonderful{''}cultivar. Total phenolic content and antiradical activity of the examined juices were found to vary in the same decreasing manner as follows: ``Porphiroyeneti{''} > ``Wonderful{''} > ``Persephone{''}. The antimicrobial activity of PJs was also determined, showing equal or higher effect than commercial antimicrobial agents (streptomycin, ampicillin, bifonazole and ketoconazole). All tested extracts demonstrated noteworthy antibacterial activity with minimal inhibitory concentration ranging from 0.05 to 0.20 mg mL(-1) and minimal bactericidal concentration ranging from 0.10 to 0.40 mg mL(-1). Moreover, PJ extracts showed satisfactory fungistatic (0.05-0.2 mg mL(-1)) and fungicidal (0.1-0.3 mg mL(-1)) activity against all fungi tested. Among the cultivars tested, ``Porphiroyeneti{''}showed slightly better antiradical and antimicrobial activity. In addition, a GC-MS methodology was developed for the determination of the phenolic profile of the extracts of PJ after different types of chemical hydrolysis. Finally, an HPLC-PDA-ESI-MSn analysis was conducted for the identification of the phenolic compounds in the extracts of PJ. In total, more than 30 nonanthocyanidinic and more than 20 anthocyanidinic compounds were identified. Our results confirm the functionality of pomegranate juices and the potential applications of PJ extracts towards novel products as food additives or preservatives.