Effects Of Spans-protein Interaction On The Interesterification Of Oils And Fats Catalyzed By Lipase

In this paper, the porcine pancreas lipase (PPLipase) was modified by Spans through theinteraction of the surfactant and the protein in ethanol solution. And the interesterificationbehavior of oils and fats catalyzed by the Spans modified PPLipase in solvent and solvent freesystem, the reaction kinetics of interesterification catalyzed by S60-PPLipase in solventsystems were also studied,The modification conditions of PPLipase by Spans were as follows, for Span20, theconditions were the ratio of alcohol to water1:4(v/v)，the amount of Span2025%. For Span40， the ratio of alcohol to water1:2(v/v)，the amount of Span4020%. For Span65, the ratioof alcohol to water1:1(v/v)，the amount of Span2020%. For Span60, Span80, and Span85,the ratio of alcohol to water1:3(v/v)，the amount of Span4020%. The mixing times ofSpans modification were30min. The catalytic activity of Spans modified PPLipases obtainedat these conditions in solvent systein was1.5-2times higher than that of the PPLipase in therang of30℃to70℃. The modification effectiveness of Span60was better than those ofothers. The interactions between Spans and protein were explored.The results of the interesterification of tea seed oil and palmitic acid catalyzed by Spansmodified PPLipases and PPLipase in solvent system indicated that at the same conditions, theacyl incorporation of the interesterification catalyzed by Spans modified PPLipases wasincreased, and the acyl migration was declined at the same acyl incorporation level,comparison to those of the interesterification catalyzed by PPLipase. The catalytic behavior ofS60-PPLipase was the best among the Spans modified PPLipases. The results of enzymeloading on the interesterification catalyzed by S60-PPLipase in solvent system indicated thatthe optimium enzyme loadings were25%at50℃and70℃, and under these conditions, thevelocity of interesterification was faster, and the reaction reached the balance in2h, the acylmigration was about25%, however the acyl migration was lower than3%.The results of the interesterification of tea seed oil and linoleic acid catalyzed by Spansmodified PPLipases and PPLipase in solvent free system indicated that at the same conditions,the acyl incorporation of the interesterification catalyzed only by S40-PPLipase andS60-PPLipases was increased, and the acyl migration was not higher at the same acylincorporation level at30℃,50℃and70℃, comparison to those of the interesterification catalyzed by PPLipase. The catalytic behavior of S60-PPLipase in solvent free system was thebest among the Spans modified PPLipases. The results of enzyme loading on theinteresterification catalyzed by S60-PPLipase in solvent free system indicated that theoptimium enzyme loadings were15%at30℃and50℃, and20%70℃.The reaction kinetics model of the interesterification of OOO and palmitic acid catalyzedby S60-PPLipase in solvent systems was established according to mass balance. The functionsof component content and time, reaction velocity and time were deduced. The averagereaction velocity (K) calculated from the established model was6.95x10-5[L2/(mmol, h, genzyme)]. The experimental values were compared well with predicted values from theestablished model.