The Study On Fabrication And Properties Of Emulsion Encapsulating LSOPC

Lotus seedpods contain a lot of procyanidins,which have unique physiological activities,such as antioxidant,anticancer,anti-radiation,anti-cardiovascular diseases,improving memory impairment,anti-aging.Procyanidins are closely related with human life.In recent years,studies on the extraction,separation,antioxidant activity and physiological activity in vivo of procyanidins have been increasing.And the researchs of the stability of procyanidins have also been reported.It was found that light,temperature,p H,Na Cl,sugar,metal ion can affect the stability of procyanidins.In order to improve the stability and biological activity of functional nutrients,constructing carriers,such as emulsion,liposome,solid lipid nanoparticles,has become the focus and hot spot of the researchs.Researchs about embedding and improvement of bioavailability of carotenoids,flavonoids,sterols have been largely reported,but the preparation and stability of emulsion encapsulating oligomeric procyanidins from lotus seepods at present are rarely reported.Therefore,this paper aimed at studying the preparation of emulsion encapsulating oligomeric procyanidins from lotus seepods,the effects of various factors on the stability of emulsion,the antioxidant activity and the interaction with protein of LSOPC in emulsion,and changes of emulsions as they pass through an in vitro digestion model.Specific contents and results are as follows:1.Emulsion was fabricated using low-energy method.The effects of proportion of emulsifiers,content of emulsifiers and content of oil on emulsion were studied.The weight ratio of Tween 80 and Span 20 at 3:1,the content of compound emulsifiers at 12%,the content of oil at 4%were the best preparation conditions.The particle size of emulsion was the smallest.The prepared emulsion was oil in water emulsion,and the particle size distribution showed a single peak.The average volume diameter of emulsion was 0.363±0.020μm,and the zeta potential of emulsion was-10.83±0.57 m V.The distribution and size of emulsion was uniform.Emulsion droplets existed in the form of single entities rather than in the form of aggregates,which showed a spherical dispersion system.The emulsion showed the characteristics of Newton fluid.The effects of various factors on the stability of emulsion were studied.It was foond that when p H was at 2.0～10.0,p H had no significant effect on the stability of emulsion.Low temperature didn’t affect the particle size of emulsion,but the effect of high temperature on the stability of emulsion was particularly significant.The concentrations of Na Cl at 0～1.0 mol/L were no significant effect,and when the concentration of Na Cl were 1.5,2.0 mol/L,the particle size of emulsion increased significantly.The quality score of less than 9%glucose and sucrose had no significant effect on the stability of emulsion,the emulsion can have very good stability.When K⁺,Mg²⁺,Zn²⁺and Al³⁺were added,the particle size of the emulsion did not change significantly.They had no significant effect on the stability of the emulsion.After adding Ca²⁺,Fe²⁺,Cu²⁺,and Fe³⁺,the particle size of the emulsion increased to some extent.They significantly affect the stability of emulsion.2.On the basis of the preparation condition,different concentrations of LSOPC were added to abtain emulsion encapsulating LSOPC.It was found that the particle size of the prepared LSOPC emulsions had no significant difference.The absolute value of zeta potential of different concentrations of LSOPC emulsions were less than 25 m V,which were not conducive to the stability of emulsions.Droplets of LSOPC emulsions existed in the form of single entities rather than in the form of aggregates,which showed spherical dispersion systems.The distribution of emulsions with different concentrations of LSOPC was different.The distribution of 0.055%LSOPC emulsion was the most uniform,and the distribution of 0.1%LSOPC emulsion was relatively disordered.The LSOPC emulsions showed the characteristics of Newton fluid.The stability of LSOPC emulsions was investigated.When p H was at 2.0～8.0,LSOPC emulsion was stable.When p H was at 10.0,p H had significant effect on the stability of LSOPC emulsion.LSOPC emulsion was demonstrated to be stable under low temperature condition.Low concentration Na Cl,glucose and sucrose had little impact on the stability of LSOPC emulsion.K⁺、Mg²⁺、Cu²⁺、Al³⁺had less effect.Ca²⁺、Fe²⁺、Zn²⁺、Fe³⁺were found to affect the stability of LSOPC emulsion,the particle size of LSOPC emulsions increased to different extents.The content of LSOPC could be determined by the method of hydrochloric acid-butanol at 546 nm.And the proportion of LSOPC in the water phase of emulsion would gradually decrease with the increase of LSOPC concentration and time.3.The IC₅₀values of free radical DPPH scavenging activity of LSOPC emulsion and LSOPC solution were 6.55±0.04 and 7.33±0.04μg/m L respectively.In the experiment of reducing the iron,reduction ability of LSOPC emulsion was better than LSOPC solution at the same mass concentration.In peanut oil oxidation experiment,results suggested that compared to the un-encapsulated antioxidants,antioxidants in emulsion could better inhibite the production of hydrogen peroxide.However,without the addition of antioxidants,primary oxidation products produced in emulsion was higher.Un-encapsulated antioxidants had consistent change trend of TBARS products with antioxidants in emulsion,but the concentration of the generated TBARS was much higher.Therefore,antioxidants in emulsion had better oxidation.BSA could interact with LSOPC.when LSOPC was encapsulated,quenching phenomenon still occured,but the strength would become weak.4.The color,p H,particle size and zeta potential of the blank emulsion and LSOPC emulsions were changed as they passed through an in vitro digestion model.The L value of the blank emulsion and LSOPC emulsions decreased with the digestion process.The brightness of emulsions decreased gradually.In saliva and gastric juice,the particle size of the emulsions increased.In intestinal fluid,the particle size of the emulsions decreased.Zeta potential of emulsions is negative during digestion process.It decreased to the lowest value in gastric juice and increased in intestinal juice.Blank emulsion and LSOPC emulsions in the small intestine were hydrolyzed by lipase without lag phase.The release rate of FFA in emulsions reached about 55%.LSOPC in the emulsion of bio release rate of LSOPC in emulsions was higher than that in solution.