Transesterification of soy lecithin by lipase and phospholipase

Abstract

Soy lecithin was modified by enzymatic transesterification in a solvent-free system. 1,3-Specific Rhizomucor miehei lipase was found to be efficient in the transesterification with lauric acid and oleic acid, where oleic acid was more incorporated into soy lecithin. Phospholipase A 2 incorporated lauric acid hardly at all, but it hydrolyzed lecithin efficiently. The mixture of lipase and phospholipase A 2 (1:1, w/w) incorporated lauric acid to the same extent as did 1,3-specific lipase alone at the same tota[ enzyme concentration. The main fatty acids replaced were palmitic and linoleic acids by 1,3-specific lipase and its mixture with phospholipase A2, and linoteic and linolenic acids by phospho[ipase A 2 alone, suggesting an improved oxidative stability of the resulting product. Hydrolysis could not be prevente.d, but it could be regulated by incubation time and by enzyme dosage. The rninimal water content for significant incorporation of lauric acid into lecithin was below 0.5% of the weight of the reaction mixture. ]AOCS 72, 1375-1379 (1995).

Synthesis of structured phospholipids by immobilized phospholipase A2 catalyzed acidolysis

“…High concentrations of Ca 2+ give rise to sever inhibition of synthesis reactions. In some cases the dependence of Ca 2+ is simply overcome by doing the immobilization in buffer containing CaCl 2 (Egger et al, 1997;Aura et al, 1995;Lyberg et al 2005). Pernas et al (1990) reported that initial rate of PL synthesis conducted in organic solvent was dependent on the pH of the last aqueous solution in which the enzymes were exposed; however the maximum conversion was not dependent on the pH in the range 4-11.…”

“…Pancreatic PLA 2 has requirement of calcium ions and a water activity above 0.2 to be catalytically active, which means that low yields can be expected compared to lipase-catalyzed reactions that can function in nearly anhydrous reaction systems without the presence of calcium ions (Pernas et al, 1990, Adlercreutz et al, 2003. Commercial product of PLA 2 has so far only been provided in the free form (liquid solution), but some attempts have previously been made to immobilize the enzyme (Aura et al,1995;Doig and Diks, 2003;Härrod and Elfman, 1995;Hossen et al 2005;Lyberg et al 2005). Main reason to use immobilized enzymes is the ability to isolate the biocatalyst from reaction mixture as well as to improve the stability.…”

“…Some attempts have previously been made for transesterification; however in general the incorporation of fatty acids into the sn-2 position is rather low (<15%) (Aura et al, 1995;Hossen et al, 2005;Park et al, 2001).…”

Phosphatidylcholine enrichment with medium chain fatty acids by immobilized phospholipase A1‐catalyzed acidolysis

“…18 Since 1994, the use of MCFAs in food products is recognized as safe by the FDA. 19 Several studies have been published concerning the modification of PLs using lipases, 2,[20][21][22][23][24][25][26][27] phospholipase A 1 (PLA 1 ), [28][29][30] and PLA 2 31-35 by incorporation of saturated, mono-or polyunsaturated fatty acids. However, very few specific reports concerning the incorporation of MCFAs in soybean lecithin (PC) by lipase-mediated reactions have been published.…”

Use of immobilized phospholipase A1-catalyzed acidolysis for the production of structured phosphatidylcholine with an elevated conjugated linoleic acid content

“…When we evaluated the different enzyme loadings, higher incorporations were attained as the enzyme load increased, and this effect was favored by temperature. It has been reported that high enzyme loads are needed for an effective incorporation of novel FA into PL by acidolysis in a solvent-free system (Haraldsson et al, 1999;Aura et al, 1995). However, the use of high enzyme loadings produced problems with agitation and decreased mass transfer.…”