Antimicrobial, antioxidant and anticancer properties of globe artichoke and grape by-products as a source of the bio-active phenolic compounds

Grape pomace and non-edible parts of globe artichoke were investigated in this study as a rich source of the bioactive compounds. Phenols and flavonoids were determined using HPLC analysis. Biological activities of artichoke and grape by-product extracts were evaluated as antimicrobial, antioxidant and anticancer agents. Artichoke and grape wastes were applied as preservative edible coating films for chicken breast meat and counts of microbial groups were followed during storage. Grape seed extract (GSE) had the highest amounts of phenols (67 mg GAE/g) and flavonoids (46.5 mg QE/g), followed by artichoke floral stem extract contained phenols (62.2 mg GAE/g) and flavonoids (35.31 mg QE/g). Similarly, GSE gave the highest significant DPPH scavenging activity (91.6%) followed by artichoke floral stem extract (89.2%). The tested extracts inhibited the growth of all target microorganisms. The highest inhibition zone diameter was 63.3 +/- 1 mm for GSE against Bacillus subtilis, while the lowest inhibition zone diameter was 11.6 +/- 1.52 mm for artichoke bracts extract (ABE) against Candida albicans. For cytotoxicity, GSE caused the greatest inhibition effect against all the treated cell lines (IC50; 20.4 -53.2 mu g/ml), followed by grape seedless pomace extract (GSPE) (IC50; 22.9 -57.1 mu g/ml), whereas ABE had the lowest cytotoxic effect (IC50; 143 -329 mu g/ml). All investigated by-product powders revealed inhibitory effect on the microbial groups causing a decrease in counts or complete disappearance of cells during one week of storage at 4 +/- 1 degrees C for the coated chicken samples. Finally, artichoke and grape by-products represent effective natural food preservatives and sources of pharmaceutical bioactive agents.