Sprouting olive (Olea europaea L.) seeds as a source of antioxidants from residual whole stones

Total phenolic content (TPC) and antioxidant activity (AOXA) of olive (Olea europaea L.) sprouts were measured in three cultivars (Arbequina, Moraiolo and Leccino). Olive seeds, obtained by manually breaking whole stones derived from de-stoning ripe fruits, were sown in plastic trays and subjected to cold stratification for 30 days. The trays were then moved to 25 °C and 16:8 light:dark regime. Total germination was 27% in Arbequina, 18% in Leccino, 14% in Moraiolo. Mean germination time (MGT) was 10 days in Leccino and Moraiolo and 14 days in Arbequina. Shoots were progressively harvested once the cotyledons were completely unfolded, i.e., between 8 and 16 days after germination. Sprouting dramatically increased TPC and AOXA in all cultivars (on average, 14 and 30 times higher, respectively, compared to seeds), with Moraiolo and Leccino showing higher values than Arbequina. Sprouting olive seeds appears to be a valid way to obtain antioxidants for food supplementation or pharmaceutical purposes.