J. Oleo Sci.Ultrasound Assisted Synthesis of Hydroxylated Soybean Lecithin from Crude Soybean Lecithin as an EmulsifierPranali P. Chiplunkar and Amit P. Pratap＊Department of Oils, Oleochemicals and Surfactants Technology, Institute of Chemical Technology, Mumbai-400019, INDIA1 INTRODUCTIONLecithin can be DEFINED as a byproduct of oil processing, which is a complex mixture comprises of phospholipids（PLs）and triglyceride（TG）along with other minor compo-nents such as phytoglycolipids, phytosterols, tocopherols and fatty acids produced by degumming step of crude veg-etable oils refining1）. The majority of commercial lecithin is derived from vegetable oils such as soybean. Lecithin con-tains major amount of phospholipids, which are polar lipids having surface-active properties. The important phospho-lipid components of soybean lecithin are phosphatidylcho-line（PC）（ 13％-18％）, phosphatidylethanolamine（PE）（10％-15％）, phosphatidylinositol（PI）（ 10％-15％）and phosphatidic acid（PA）（ 5％-12）. Phospholipids（PLs）have both hydrophilic head and non-polar hydrophobic fatty acid TAILS. As amphipathic molecules, they tend to adsorb to surfaces or interfaces with the non-polar fatty acid tails facing the surface or oil phase and the polar heads facing the water phase, RESULTING in a decrease in the surface or interfacial tension2）. The presence of both hydrophilic and lipophilic groups in PLs makes them widely USED as emulsi-fying agents or surface active agents. Soybean lecithin has