**Polar Lipids from Olives and Olive Oil: A Review on Their Identification, Significance and Potential Biotechnological Applications**

#### **Eliana Alves \*, M. Rosário M. Domingues and Pedro Domingues**

Mass Spectrometry Centre, Department of Chemistry & QOPNA, University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal; mrd@ua.pt (M.R.M.D.); p.domingues@ua.pt (P.D.)

**\*** Correspondence: elianaalves@ua.pt; Tel.: +351-234-370-695

Received: 15 June 2018; Accepted: 6 July 2018; Published: 10 July 2018

**Abstract:** Polar lipids are minor components of olives and olive oil and include a myriad of molecules such as phospholipids and glycolipids. Even though sensitive and high-resolution analytical approaches have been used to unveil the polar lipidome of these matrices, new insights on their composition are needed. In this review, we will describe the findings on the identification and characterization of polar lipids from olives and olive oil and the underlying analytical challenges. The significance of polar lipids will also be discussed as potential markers of identity and traceability of olives and olive oil and in detecting adulteration of olive oil. Their potential impact on nutrition and health will be presented as a valuable source of bioactive compounds and as promising ingredients for different uses from olive-derived industrial by-products.

**Keywords:** authentication; bioactive; by-product; glycolipid; lipidomics; mass spectrometry; phospholipid; traceability
