Research On The Extraction Of Lutein And α-triplethiophene From Marigold And Antibacterial Activity Of α-triplethiophene

In order to improve the utilization of marigold resources and increase its value, in this thesis,a kind of high-content and high-purity natural pigment lutein was obtained from the marigoldused as raw material which is ultrasonic extracted, saponificated, absorbed and purified bymacroporous resin. At the same time, in order to save marigold resources, the marigold residuewas reused to extract the photosensitive material α-terthiophene which would be studied onantibacterial effect. The main contents are as follows:The experiment was carried out for the optimum condition on which organic solvent canextract marigold lutein esters with ultrasound assisting, based on the single experimental factor,with lutein ester yield as response value, putting two rotational regression combination designand statistical analysis method by the software of SAS9.1to use, the mathematical regressionequation, the response surface and contour map of the ultrasonic extraction for lutein esters frommarigold were achieved, the optimum process conditions of ultrasonic assisted with solventmethod was: petroleum ether acted as extraction solvent (boiling range of60℃～90℃),20solvent ratio, extraction temperature40℃, extraction time90min, ultrasonic power150W.Under above conditions, the yield of lutein was18.57%.During the ultrasonic method assisted with KOH-alkali solution, saponification process wasstudied on the variables of alkali concentration, the amount of alkali, saponification time andsaponification temperature. Through the response surface analysis method, the impacts ofvarious factors on marigold lutein ester saponification were discussed. The results showed thatthe optimum conditions for lutein ester saponification were as follows: When KOH-alkalisolution concentration was10.68%, lye amount was161mL, saponification temperature was53.27℃,and saponification time was2.06h, the predicted value of lutein was15.53mg·g-1.When the KOH-concentration of alkali solution was controlled at11%, the amount of alkali was160mL, saponification temperature was50℃, and the time of the saponification was set as2h,the accurate yield of lutein content was15.64mg·g-1. The processing parameters obtained wereconsistent with the model predictions, which indicated that this model had a better reliability andpredictability.The experiment of using macroporous resin to separate the lutein in marigold was based onmaking comparison among six kinds of resin (HZ818, X-5, NKA-9, HPD-722, AB-8andADS-17) on the static adsorption of lutein analytical results, finally adsorption effects of HZ818, AB-8and HPD-72resin were confirmed better. On this basis, countering the static adsorptionanalytical conditions，comparisons of three kinds of resin were further studied, experimentalresults showed that the analytical effect of HZ818adsorption was best, therefore, the optimumconditions for the static adsorption was resolved: Adsorption time was3h, adsorptiontemperature was25℃, the elution time was2.5h, elution temperature was30℃. As dynamicadsorption and analysis tests with the resin HZ818, the results showed that when theconcentration of the sample solution was2.073mg·mL-1, pH value of the sample liquid was3,the sample flow rate was2BV·h-1, the ethanol concentration was75%, the volume of eluent was5BV, elution rate was2BV·h-1, the purity of the lutein measured by HPLC method reached94.71%.With marigold residue as raw material, the optimal technological parameters of soxhletextracting α-terthiophene from marigold residue was defined: solid-liquid ratio was1:35,extraction time was8h, extraction temperature was50℃; then the measured content ofα-terthiophene was0.673mg·g-1. With the method of ultrasonic extraction, the optimalparameters of extracting α-terthiophene from marigold residue: ultrasonic frequency was70KHz, solid-liquid ratio was1:30, ultrasonic time was40min, ultrasonic temperature was50℃;on these basises, the measured content of α-terthiophene was0.924mg·g-1. Comparing with thesoxhlet extraction method in the extraction of α-terthiophene, the ultrasonic extraction methodwas0.251mg·g-1higher, therefore the choice of ultrasonic extraction was more satisfying.The antibacterial activity tests of α-terthiophene to several common food spoilage bacteriawere studied by the filter paper method, the conclusions were as follows: α-terthiophene hadgood antibacterial activity against escherichia coli, penicillium, salmonella, and the antibacterialeffects on E.coli and penicillium were the most obvious, minimum antibacterial concentrationvalue was0.15mg·mL-1.