CONTROL OF LIPASE-MEDIATED GLYCEROLYSIS REACTIONS WITH BUTTEROIL IN DUAL LIQUID-PHASE MEDIA DEVOID OF ORGANIC-SOLVENT

Factors affecting the progress of glycerolysis reactions with butteroi l mediated by two lipase preparations (from Pseudomonas sp.) in dual l iquid phase mixtures devoid of solvent were evaluated. Within the rang e of parameters evaluated, the conditions best supporting the formatio n of monoacylglycerols (MAG) were 35-degrees-C, 2.5-4.8% water in glyc erol, and 0.33-0.44 g of glycerol/g of butteroil (equivalent to a mola r ratio of acyl groups to glycerol of 0.66-0.85). Under these conditio ns, percent yields of MAG formation from butteroil were 50-55% (mass f raction) relative to the other acylglycerol species and fatty acids ac cumulated. Little interaction was observed between these critical para meters. At temperatures greater than 35-degrees-C, up to a 50 % reduct ion in yield of MAG was noted. Temperature shift experiments indicated that MAG and other acylglycerol components were interconvertible. Inc ubation of reactive mixtures at 35-degrees-C after a prior incubation at 52-degrees-C restored the yield of MAG from about 25% to the near-m aximal levels of 50-55 %. The effect of this temperature shift was man ifest as a net and reversible interconversion of MAG and 1,3-DAG, and changes in other acylglycerol components did not take place. Temperatu re control of reaction equilibria was not attributable to changes in a vailability of water.