Onions (Allium cepa) have been used for centuries in several societies against parasitic,
fungal, bacterial and viral infections. Recent chemical characterisation of sulphur compounds
in onions has allowed stating that they are the main active antimicrobial agents (Rose et al.,
2005). However, some proteins, saponins and phenolic compounds can also contribute to this
activity (Griffiths et al., 2002). Due to the great antimicrobial activity that onion posses, it
could be used as natural preservatives, to control the microbial growth (Pszczola, 2002).
Aqueous enzymatic oil extraction is undoubtedly an emerging technology in the fats and oil
industry since it offers many advantages compared to conventional extraction. For instance, it
eliminates solvent consumption which reportedly may also lower investment costs and
energy requirements (Barrios et al., 1990). It has been reported that the low extraction yields
of aqueous processes can be overcome by using enzymes that hydrolyse the structural
polysaccharides forming the cell wall of oilseeds, or that hydrolyse the proteins which form
the cell and lipid body membranes