Abscisic acid treated olive seeds as a natural source of bioactive compounds

Many phenolics occurring in olives are also present in the by-products, particularly in seeds, produced during olive oil processing. We investigated the effect of the treatment of olive fruits with abscisic acid on phenolics in olive seeds as compared with pulps. Effect of the storage time is also considered. The results showed that the treatment resulted in higher total phenolic content, scavenging free radical activity and oleuropein and hydroxytyrosol contents than those untreated. The effect of abscisic acid was more pronounced in pulps than in seeds and depended on the storage time. Seeds from treated olives reached values of oleuropein and hydroxytyrosol of 666 and 987 mg kg−1 which were similar to those obtained in the pulps (ie, 607 and 512 mg kg−1). Since seeds are a residue from oil processing, abscisic acid treatment is proposed a promising technique to obtain enriched olives and simultaneously a high added value by-product.