Thermodynamics Of Microporous Starch Absorbed With Tea Polyphenols And The Reduction Of Harmful Components In Cigarette

In this work,corn starches were applied as raw materials to prepare porous starch by synergism of the α-amylase and gluamaylase.The adsorption parameters of the porous starches with tea polyphenol(TP)were optimized by using the orthogonal experimental design.Based on the adsorption thermodynamic characteristics,the adsorption kinetic and adsorption mechanism were researched to evaluate the effectiveness of the compounds on reducing the tar and harmful ingredients in cigarette smoke pollution.HPLC,DPPH and ABTS radical scavenging experiments common showed the porous starch can reduce the oxidation rate of tea polyphenols.The surface morphology of porous starch was investigated by SEM.Through SEM,the raw starch turns to be loose and porous,similar to the honeycomb structure,and the distribution of porous not only on the surface,but also extends to the particles inside.Such porous structure,makes an obvious increase on surface area and pore volume,greatly increases the adsorption quantity of tea polyphenols.DSC analyzed the change of characteristics of starch enthalpy,the results showed that the enzymatic hydrolysis process priority on the amorphous region of the starch granule structure,amorphous region are destroyed,showed the porous structure,so the porous starch can maximum adsorp on tea polyphenols.Research on optimum adsorption conditions,based on single factor tests and orthogonal experiment the optimum condition were determined as follows: the adsorption temperature 20 ℃,pH of 6,tea polyphenols concentration of 4.5 mg/ml.The factors that influenced adsorption quantity of tea polyphenols were respectively temperature,time,pH and tea polyphenols concentration.Adsorption quantity of tea polyphenols under the best conditions was 25.71 mg/g.Studying on the adsorption thermodynamic characteristic and fitting the isotherms with Langmuir equation and Freundlich equation,It turned out both two can represent the adsorption isotherm.The differential heat of adsorption according to the adsorption isostere conformed to the hydrogen bonding key range,it means the adsorption belongs to the hydrogen adsorption;the adsorption kinetic was well fitted with kinetic models of Pseudo-second-order.To establish a rapid and accurate HPLC method for the determination of 7 kinds of main catechins in tea polyphenols,thus EC,DL-C,EGCG,ECG,EGC,GCG and GC,the quantification was carried out by internal standard method,and the qualitative was carried out by retention time.The catechins were separated on Symmetry C18column(4.6*150mm,5um)at 30 u.with 0.5% acetic acid:acetonitrile=88:12(v/v)as mobile phase at a flow rate of 1.2 ml/min for isocratic elution,the detection wavelengths were set at 275 nm.valuing EGCG content in complex after 30 days by HPLC,and scavenging capacity on DPPH and ABTS free radicals,common showed the protection ability of porous starch on tea polyphenols’ antioxidant capacity.It indicated that the EGCG content in tea polyphenols was reduced by 8.38% after 30 days,while the EGCG content in complex only decreased by 3.08%,and the complex still maintained higher antioxidant capacity.Research on the scavenging capability of porous starch and compound on ammonia,crotonaldehyde,hydrogen cyanide and benzo[a]pyrene.the results showed that the removal of the both have certain effect,the scavenging capability of compound was obviously better than that of the porous starch,and with the extension of time,the scavenging capability of compound reduced slowly.