Soy foods have rising popularity in European countries, due to ecological or health benefits, lactose intolerance or allergies against milk proteins. Traditional soy food such as soymilk, tofu or yuba contains small oil droplets, which have been known for many years in botany as oleosomes or oil bodies. These oleosomes are a natural oil-in-water emulsion formed from an oil phase of triacylglycerides with an emulsifier consisting of phospholipids and unique umbrella shaped proteins called oleosins which stick into the oil phase. The hairpin anchor domain consists of the longest hydrophobic amino acid sequence known to date - about 70 amino acids in the middle of the sequence.1 The exterior hydrophilic part of the oleosomes (N- and C- terminal domains) shields the phospholipids and is, because of its pH-dependent charge, responsible for the extraordinary stability of oleosomes against coalescence and creaming. We will investigate the structure of the oleosome interfacial layer to determine the mechanism of this stability with a view to the development of natural emulsifiers for the food industry.