Metal composition of table olives from the portuguese market.

Olive tree (Olea europaea L.) is one of the most important fruit trees in the Mediterranean countries. Their products, olive oil and also table olives, are important components of the Mediterranean diet and are largely consumed in the world. Table olives are well-known sources of compounds with important biological properties. The preparation of table olives follows three main trades, namely green or Spanish-style olives (Green Olives in Brine - GOB), black ripe or Californian-style olives (Black Ripe Olives), and naturally fermented olives (Direct Brined Olives – DBO). Heavy metals can be present in olive fruits for several reasons: endogenous, depending on the mineral constitution of the soils where the olive trees are located, or exogenous, resulting from the air pollution, contamination by phyto-chemical products and during technological processing. Besides the toxicological characteristics of these elements, the presence of transition metals in these fat matrices can negatively influence the organoleptic and nutritional properties as well as the shelf life of the products