Study On Esterolytic Kinetics And In Vitro Digestion Of Vitamin E Acetate Emulsion In Crowded Media

Regulating the conversion of vitamin E acetate(VE-A)in the intestine is important for the design of functional foods and beverages in the food industry:Previous studies have focused on the establishment of complex simulation digestive environments,as well as the establishment of standard methods,without taking into account the crowding of a large molecule in the real human body.Moreover,a common preparation method for the VE-A emulsion is microfluidization homogenization method or self-emulsification method,and the ultrasonic method is not used.Moreover,most of the studies examined the effects of glyceryl trioctanoate(MCT)and glyceryl trioleate(LCT)on emulsion digestion,but did not involve glyceryl tributyrate(SCT).In this study,various concentrations of polyethylene glycol 2000(PEG200)and polysucrose 400(Ficoll400)were used as macromolecular crowding reagents,and three chain length triglycerides were selected as the oil phase mixed with VE-A.The emulsion was assisted by high-speed shear-assisted ultrasonic method to investigate the effect of porcine pancreatic lipase(PPL)hydrolysis efficiency of VE-A emulsion.(1)Study on the stability of VE-A emulsion prepared by ultrasonicThe VE-A emulsion was prepared by high-speed shear-assisted ultrasonic method.The oil phase was mixed with three kinds of loading oils of SCT,MCT and LCT mixed with VE-A respectively.The results obtained were that the three emulsion oil preparation emulsions exhibited a certain stability after being left at room temperature for 24 hours and after 30 to 90 °C water bath.Among them,the average particle size of the SCT preparation emulsion is the smallest,and the-absolute-value of the C-potential is the largest,which is the most stable.(2)The Effect of Ficoll400 crowding media on lipase esterification kinetics and in vitro digestion rate of VE-A emulsion By adding different concentrations of Ficoll400 in the emulsionsystem,the effects of emulsion average particle size,pancreatic lipase catalytic hydrolysis efficiency on the preparation of VE-A emulsion,emulsion bioaccessibility and VE-A conversion were obtained.It can be seen from the DLS that as the concentration of Ficoll 400 in the system increases,the average particle size of the emulsion increases steadily.From the results of ITC,the efficiency of pancreatic lipase-catalyzed hydrolysis of VE-A emulsion prepared by three loading oils was improved in all concentrations of Ficoll400,and the efficiency of pancreatic lipase in MCT preparation emulsion was the highest.The system is also put into a more complex simulated small intestine environment,and the conversion rate of VE-A is also improved.Among them,the bioaccessibility:LCT>MCT ? SCT,VE-A conversion rate:SCT>LCT>MCT.(3)The Effect of PEG2000 crowding media on lipase esterification kinetics and in vitro digestion rate of VE-A emulsionSimilarly,in the presence of different concentrations of PEG2000,the particle size distribution of the emulsion is shifted to the right,that is,the average particle size is steadily increasing.The results obtained by ITC,are similar to those in Ficoll400.Under all concentrations of PEG2000,pancreatic lipase catalyzed hydrolysis of three loading oils to prepare VE-A emulsion is more efficient than in dilute solution,and PPL catalyzed by SCT preparation emulsion.The efficiency is up to 4.94 times.The system was placed in the simulated environment of the small intestine,and the laws on the bioaccessibility and VE-A conversion rate were consistent with those of Ficoll400,the bioaccessibility:LCT>MCT?SCT,VE-A conversion rate:SCT>LCT>MCT.From the above results,it is known that in the system in which pancreatic lipase catalyzes the hydrolysis of triglyceride-loaded VE-A emulsion,the macromolecular crowding effect is ubiquitous.In the ITC experiment,the lipase-catalyzed hydrolysis efficiency was highest in the medium-chain triglyceride(MCT)preparation of VE-A emulsion in the presence of PEG2000.In Ficoll 400,pancreatic lipase-catalyzed hydrolysis of short-chain triglycerides(SCT)to prepare VE-A emulsions was the most efficient.In vitro digestion,whether in PEG2000 or Ficoll400,the bioaccessibility and VE-A conversion rate of VE-A emulsion prepared by three kinds of loading oils showed the same regularity,and bioaccessibility:LCT>MCT?SCT,vitamin E conversion rate:SCT>LCT>MCT.These findings have important implications for the design and testing of the potential efficiency of developing emulsion delivery nutrient systems in the food industry.