“…Whereas, chemical oxidation and exogenous enzymes, usually from microbial activity, are responsible for the off-flavor referred to as oxidative rancidity Kalua et al, 2007;Morales, Rios, & Aparicio, 1997). This disagreeable sensory note is especially perceptible in oils that are strongly oxidized due to incorrect or excessively long storage and cause the consumers to reject such products (Bendini, Cerretani, Salvador, Fregapane, & Lercker, 2010;Villière & Genot, 2006). The absence of the C6 aldehydes, alcohols and esters from the lipoxygenase pathway and the presence of many saturated and unsaturated aldehydes from chemical oxidation, including hexanal, C5 branched aldehydes and alcohols and some C8 ketones, in relatively high concentrations, in the aroma of virgin olive oil, is associated with unpleasant notes (Angerosa, 2000;Gomes da Silva, Costa Freitas, Cabrita, & Garcia, 2012;Ha, Nihei, & Kubo, 2004;Kalua et al, 2007).…”