?Enzymatic oil degumming using a novel glycerophospholipid:cholesterol acyl transferase

HAILS, GUILLERMO; CERMINATI, SEBASTIAN; AGUIRRE, ANDRES; ANSELMI, PABLO; CASTELLI, MARÍA EUGENIA; PEIRU, SALVADOR; MENZELLA H. G.

Congreso; SAIB 2018; 2018

SAIB

Abstract: In the last decades, the need for oils to be used as food and for the production of fuels has been in constant increase. Crude vegetable oils are a complex mix of triglycerides, phospholipids (or gums), sterols, glycolipids, tocopherols, free fatty acids, metallic traces and other minor compounds. The refining of oil involve many steps, including the removal of phospholipids (also known as oil ?degumming?), which causes the major losses in the industrial process of oil refining. Thus, degumming is an important issue that needs to be addressed with cost effective methods. Traditionally, physical and chemical methods have been used. More recently, developments were made to use enzymatic degumming, which possess several advantages over chemical and physical processes. Enzymatic degumming has been employed using a wide variety of enzymes to hydrolyze phospholipids, generating products that are more easily removed by centrifugation. The most common enzymes used are phospholipase C (PLC) and phospholipase A (PLA), which reduce the phospholipid content and leave less oil trapped by the gums. Thus, upon enzymatic treatment the overall yield increases, which represents a significant economic benefit for the oil industry. Glycerophospholipid:cholesterol acyl tranferases (GCAT) are enzymes that attack acyl groups from phospholipids just like PLA enzymes. However, they additionally transfer the acyl group to a free sterol, reducing the amount of free fatty acids in treated oil. In this work, 6 different GCAT candidates obtained from an in silico analysis were evaluated in terms of their expression, thermal stability and ability to remove phospholipids using oils with different phospholipid contents, expecting to formulate a new enzyme for oil degumming. A GCAT from Aeromonas enteropelogenes was selected, due to its ability to work at temperatures up to 60 ºC, and to efficiently remove all phospholipids from crude oils (1200 ppm of phosphate). These and other features from this GCAT from A. enteropelogenes are described herein.