In-vitro antioxidant and antimicrobial activities of some varieties citrus grown in Algeria

Polyphenols are scientifically researched molecules because of their multiple biological activities. This study aims to compare the phenolic content and estimate the antioxidant and anti-microbial activities of leaf extracts and juice of ten varieties Citrus fruits grown in Algeria. Antioxidant properties were evaluated by DPPH radical scavenging activity, beta-carotene-linoleic acid system and ferric reducing antioxidant capacity. Antimicrobial activity was carried out using agar well diffusion method. The results showed the highest levels of phenolic compounds in juice and leaves of different part and varieties of plant (*P<0.05). Among all the varieties, C. maxima and C. aurantium presents the highest activity for the three methods cited previously (94.44-91.66% and 95.41-83.84%). On the other hand, antibacterial activity present on the plates was indicated by an inhibition zone surrounding the well containing the juice. The C. Limon and C. aurantium varieties exhibited the highest antimicrobial activity, with inhibition zone ranging from (27.66 +/- 0.58, 24.66 +/- 1.53 mm) followed by grapefruit and mandarin with areas between (23.00 +/- 1.00, 17.66 +/- 0.58 mm) on the isolates used. In this study, whatever the parts of citrus (juice and leaves) have been found to contain higher amounts of phenolics and their efficiency as potent antioxidants and antimicrobial properties was confirmed.