Interesterification activity of Rhizopus delemar lipase in phospholipid microemulsions

The interesterification of olive oil with palmitic acid catalyzed by Rhizopus delemar lipase was investigated in phospholipid microemulsion systems. Soybean lecithin was used as the amphiphilic component. The maximal reaction rate was obtained at a buffer pH of 5.5-6.0. The reaction rate was also dependent on the W-L (= [H2O]/[lecithin]) value and attained a maximum at W-L = 5. The reaction rate reached a maximum at a palmitic acid concentration of 350 mM. The molar fraction of the interesterified product 1,3-dipaimitoyl-3-oleoyl glycerol (POP) in the olive oil was enhanced from 2.8 to 65.6 mol% after 24 h of the reaction. (C) 2004 Elsevier B.V. All rights reserved.