Antioxidant and antimicrobial activity of gamma-irradiated chicory (Cichorium intybus L.) leaves and roots

The ethanolic and methanolic (50%) extracts of γ-irradiated chicory (Cichorium intybus L.) leaves and roots (at dose levels of 0, 4, 8 and 12 kGy) were prepared to be used as natural antimicrobial and antioxidant agents. The total phenolic contents (TPC) and total flavonoid contents (TFC) were determined in leaves and roots extracts followed by identification and quantification of the phenolic compounds using HPLC. The antioxidant activity was determined by DPPH and FRAP methods. The antimicrobial activity was verified by agar well diffusion assay against B. cereus, S. aureus, E. coli, P. aeruginosa,K. pneumonia, A. niger and P. expansum. The obtained results showed that 4 and 12 KGy doses significantly increased the TPC, TFC and enhanced the antioxidant activity of roots and leaves, respectively. Twenty-three phenolic components were identified in leaves and roots extracts. The antimicrobial assay of all extracts exhibited considerable antibacterial activity against all tested bacterial strains with slight differences between plant part extract and had no effects against tested fungal strains. Therefore, the extracts of chicory under study would be a potential source of natural antioxidant and antibacterial and offers lots of opportunities for future application in the food industry to produce healthy food and can be used in pharmaceutical industry.