Olive pomace phenolics extraction: Conventional vs emergent methodologies

Olive oil production has been steadily increasing. Along with the growth of this sector, a high rate of wastes is produced. Olive pomace presents high levels of phenolic compounds with potential applications in food, cosmetic and pharmaceutical industries. Sustainable and cost-effective technologies for bioactive compounds recovery are required. In this work, conventional extraction methodologies were compared with an ultrasound technique using a probe and only water as solvent. Total phenolics and antioxidant activity of the extracts were assessed. A conventional solid-liquid extraction (hydroethanolic solvent, 40 degrees C, 60 min) was the best procedure to recover phenolics compounds from pomace (487 mu g GAE/ml). However, in only 5 min, the sonication probe allowed significantly higher yields of recovery compared to aqueous conventional extraction (60 min) (402 and 257 mu g GAE/ml, respectively). Therefore, it seems to be a very promising technique to obtain antioxidants from olive pomace in an organic solvent-free medium.