"The oleosin protein (molecular weight of between 16 and 24 kDa), is unique in that it is made of both hydrophilic and hydrophobic portions, in which some of the hydrophobic portion penetrates into the inner triglyceride core and serves as an anchor. The remainder resides on the surface of the oleosome. This amphophilic nature of the protein COAT is what gives the oleosomes their unique self-emulsifying/emulsifying capabilities."

http://www.personalcaremagazine.com/print.aspx?story=714


"Electron microscopic and biochemical investigations of developing embryonic mustard cotyledons provided no evidence for the widely accepted hypothesis that oleosomes of fat-storing tissues originate from the endoplasmic reticulum and are surrounded by a unit- or half-unit membrane. In contrast, it was found that the first lipid droplets appear (about 12-14 d after pollination) in the ground cytoplasm near the surface of plastids. Subsequently these nascent lipid droplets, which lack any detectable boundary structure at this stage, become encircled by a cisterna of rough endoplasmic reticulum. At the same time an osmiophilic COAT of about 3 nm thickness becomes detectable at the lipid/water interface."

http://www.ncbi.nlm.nih.gov/pubmed/24408469