Preparation Of Mixed Monoacylglycerols From Soybean Oil And Sunflower Seed Oil And Immobilizayion Of Lecitase Ultra

Monoglycerides （MG） produced by esterification synthesized by glycerol andfree fatty acid and transesterification synthesized by glycerol and oil. It is a foodemulsifying agent with characteristics of safety and stably. The objective of this paperwas to prepare MG from esterification and transesterification of soybean oil andsunflower oil which were rich in unsaturated fatty acid with the catalysts ofphospholipase A₁and solid super acid(SO₄^2-/ZrO₂-Al₂O₃).1. Immobilization of phospholipase A₁（Lecitase Ultra）. D101resin was bestselected from nine types of macroporous as the carrier for this immobilization. Theoptimal conditions for immobilization of this enzyme were: ratio of enzyme solutionto carrier1:1（v/w）, adsorption time60min at ambient temperature, and phosphatebuffer pH6.5. The activity of immobilized Lecitase Ultra under the optimalconditions was750.0U/g.2.MG preparation catalyzed by lab-made immobilized phosphplipase A₁.The optimal conditions for MG preparation were: reaction temperature45℃, reactiontime10.0h, mole ratio of glycerol to sunflower oil2:1, the dosage of enzyme9%, thedosage of water8%. Under these conditions,28.81%of MG were yielded.3. MG preparation from esterification and transesterification of soy fattyacid and soybean oil with glycerol catalyzed by solid super acid and furtherpurified by two-stage molecular distillation. The optimal conditions for preparationof MG catalyzed by solid super acid using response surface methodology were asfollows: reaction temperature200℃, solid super acid catalysts loading0.26wt%（oilmass）, mole ratio of fatty acid to glycerol1.92:1, and reaction time5.0h. Under theseconditions, the yield of MG reached over70.01%. After the glycerides were degassedand dehydrated at90℃, the free fatty acid and glycerol in the glycerides wereremoved at evaporator temperature of135℃in the first stage. And distilled atevaporator temperature of185℃at the second stage, The purity of MG reached96.54wt%. 4. MG preparation from sunflower oil and sunflower fatty acid with glycerolby esterification and transesterification. The optimal conditions for this processwere: reaction temperature200℃, solid super acid catalysts loading0.2wt%（oilmass）, mole ratio of fatty acid to glycerol2:1and reaction time3.0h. Under theseconditions, MG in the glycerides phase after reaction reached56.82%. After furtherdistillation of135℃and evaporation at185℃，the MG was purified to93.76wt%.