Characterization of oils obtained from the co-pressing of olives and oleaginous matrices with high nutritional value and determination of their oxidative stability

Olive oil has always been one of the main components of the Mediterranean diet. Compared to other vegetable oils, extra virgin olive oil (EVO) has a unique chemical composition that also determines its beneficial effect on human health. The aim of this work was emphasise and improve the functional and health quality of the EVO by co-pressing olives with other valuable oil matrices, like grape seeds (GS) and pomegranate seeds (PS) that are usually by-products. After a lipidic characterization of the oleaginous matrices, the seeds (GS and PS) were co-pressed with olives and the composition in fatty acids, antioxidants (tococromanols and total phenols), sterols and the oxidative stability of the final oils (OG and OP) were determined, compared to a control sample (olive oil, O). The obtained data underline how the selected raw materials represent an important source of bioactive substances that can help make EVO oil an even more interesting and precious product. However, the results about co-pressed oils are partially positive because they still show a profile not so different from the control (O). So, it is necessary re-evaluate the percentage ratios between olives and the different oilseeds. In particular, the OP oil showed the best profile in bioactive compounds, but the oxidative stability should be improved, suggesting protective and small packaging in order to guarantee its maximum quality. In conclusion, these co-pressed oils are potentially very interesting for "noble" cold uses, finding the approval of the most demanding consumers, sensitive also to environmental issues