Olive stones as a source of antioxidants for food industry

The aìm of 1his work was to produce a polar cxtract wilh antioxidant propcrties to be used in thc food and cosmetic ìndustrìes, as functìonal foods and nutract:utieal additivces. starting from the olive stones, a by-product in the destoned Extra Virgìn Olive Oil productìon. Thc multìstep extraction procedure to produce the ethanolìc extract of olive stones significantly increases the economic value of a cheap, renevable and potentially rich source of antioxidant compounds. The impact of extraction method and the efficiency of the solvent extraction were evaluated by runnìng the same extraction protocol using solvents wìth different polarity. For each solvent, the recovery yieId and the total phenol compounds were determìned. The evaluation of the antioxìdant activitv of the aicoholic fraction was performed by measurìng the total antìoxidant aclivity and the scavanging propertics against 2,2--diphenyl-1-picrylhydrazyl radical, which show the efficiency of the potar extract in preventìng the damages induced by free radicals, with low inhìbitory concentratìon /C30 (concentration required to reduce initial DPPH concentration by 30%) value (0.060 mg· ml·'). In addition, the concentratìons of totaI phenols and flavonoids ìn the extract were determined, showing that flavonoids represent about thc 60% of antioxidants with phenolic groups. Finally. the extract showed a relevant abilìty (IC30 of 1.30 mg·ml· 1) to preserve b-carotene frorn lipidic peroxidation.