| Sesame cultivation has been of a long standing history. It is not only rich in fat and high quality protein, also rich in active substances with the nature of stability, unique features of fat-soluble and water-soluble. At present, sesame is mainly used as the raw material for making special flavor fat and low graded protein. It has important significance to study and make advantages of these biological activities.Take sesame seeds as raw material, this paper focuses on study distinct influences of extraction efficiencies of sesame oil and biological activity substances by adopting different technical process; take organic solvent or water as medium, under subcritical conditions, study different effects of separating sesame oil, sesame lignans as well as biologically active substances; study the conditions, results and mechanism of transformation between biological activity substances during sesame oil refining process; and also study the main active presentation and potency of these active substances in living organism. The results are as follows:Traditional aqueous extraction and hot pressing methods can produce featured sesame oil with strong aroma and oxidation stability, but their oil yield rates are lower than 80%. For the aqueous extraction method, the extraction time is very long, the color of sesame oil is much dark, and it is more trouble to dry the moisture out of or to dispose of the sesame dregs, so causing environmental pollution index is high. By means of supercritical or subcritical extraction at low temperature, the sesame oil yield efficiency is higher, and oil color is light, also sesame lignans (sesamin and sesamolin) content is higher.Comparing with the supercritical extraction, the sesame oil yield of subcritical extraction is much higher, and to raise extraction temperature, prolong extraction time and increase extraction times as well as reduce the ratio of solid to liquid, it is conducive to the extraction of sesame oil. The suitable conditions of subcritical butane extraction for sesame oil are:material liquid ratio 1:4/g·mL-1 extraction 5 times, extraction temperature at 50C°, extraction time 30 min, extraction pressure at 0.8 MPa. Under these extraction conditions, the sesame oil extraction rate can reach at 95.60%. Butane as extracting agent was studied, under the condition of subcritical conditions sesame seed solid-liquid dynamics. Assuming that sesame seeds are nearly spherical, sesame seed solid-liquid extraction with five process, according to the physical model and Fick’s second law, a dynamic model of the subcritical butane extraction of sesame oil:Y=Y∞(1-e-kt), the experiments verify that the model can well fitting data extraction of sesame oil, correctly estimate the subcritical extraction yield of sesame oil.Observing through electron microscopy, the morphology of sesame seed before to be extracted, it appears no uniform grain size, uneven thickness and irregular shape; After being subcritical extracted times, it emerges approximate grain size, porous morphology. This fact indicates that, under the conditions of subcritical extraction, the fluid has better functions of fragmentation and penetrations, it increases the solid-liquid contacting area and improves extraction yield.Using subcritical extraction at higher temperature to extract sesame oil and sesame lignans, it has consistent selectivity; while, at lower temperature the subcritical extraction has better selectivity to sesamin and sesamolin. Oil yield as well as contents of sesamin and sesamolin in the extracted oil will be significantly decreased along with extraction time prolonging. The contents of sesamin and sesamolin in the extracted sesame oil reach at the highest level when extraction time is 10 min, the extraction rates were 92.12% and 95.62% respectively. Sesame oil extracted is of long oxidation induction time with good oxidation stability.The substances of fat-soluble and water-soluble can be fractionated out from sesame seeds by means of the subcritical water extraction device. After comparing the conditions and influencing factors, it is found that the extraction rate of sesaminol triglucoside by the subcritical water extraction is higher than that by ultrasonic assisted extraction. Subcritical water extraction conditions for extracting water-soluble lignans are:water flow speed is 5 L·h-1, solid to liquid ratio is 1:40/g·mL-1, temperature at 120C°, extraction time is 15 min, extraction pressure at 5 MPa, sesaminol triglucoside content in sesam oil is 1.45 mg·g-1 the extraction rate was as high as 93.51%. While subcritical water extraction conditions for extracting fat-soluble lignans are:water flow rate is 5 L篱’!, the solid to liquid ratio of 1:40/g·mL-1, extraction temperature is 160C°, extraction time is 20 min, pressure at 5 MPa, fat-soluble lignans content in sesame oil is 4.11 mg·g-1, the extraction rate was as high as 80.59%. Dynamics model of the subcritical water extraction of sesaminol triglucoside:y= 1.165e-0078t, by the test value and nonlinear regression equation fitting degree R2=0.9972, the model is very good estimation of the sesaminol triglucoside extraction yield with subcritical water extraction.A rapid analysis method has been formed for the high performance liquid chromatography (HPLC) of sesaminol triglucoside. The method takes methanol (A) and water (B) as the mobile phase in gradient elution, and it is more rapid, accurate and convenient. The separation of sesaminol triglucoside, purified by UV spectrophotometer and HPLC qualitative and quantitative, identified as sesaminol triglucoside, the purity is more than 98% and used as standard.The transformation of asarinin is related to oil producing process. From cold pressed, supercritical and subcritical extracted sesame oil samples, there are no detected asarinin; while, from hot pressed and aqueous extracted sesame oil samples, only the trace of asarinin has been detected. During oil producing process, the high temperature and time is advantageous to the conversion of sesamin to asarinin, but it needs under acidic conditions to complete the transformation. Refining process of extracted sesame oil can urge great changes between element contents of sesame lignans and asarinin is generated in large amounts resulting the highest content. For the cold pressed sesame oil which is no asarinin, after being refined, the asarinin content has been increased significantly, hydration degumming and bleaching by activated bleaching earths are the main sections which makes asarinin content increased, and more over, the asarinin content increase will be along with additive amounts of phosphoric acid for hydration degumming and bleaching earths for bleaching. The alkali refining for deacidifi cation, activated charcoal for bleaching as well as deodorization processes of oil refining have not effect on formation nor content of asarinin.Using hydrochloric acid-ferric trichloride as compound catalyst, the epimerization of sesamin and asarinin were preliminary investigated, coordination and synergistic effect of Fe3+ can effectively reduce the amount of single hydrochloric acid catalyst, mass fraction of 0.5%o～5%o ferric trichloride-hydrochloric acid volume concentration of 10%o, consistent with the catalytic effect using a single volume fraction of 20% hydrochloric acid, compound catalyst can reduce the dosage of catalyst and also avoid the destruction as asarinin active substance. Using hydrochloric acid-ferric trichloride catalytic isomerization of sesamin, the temperature should be higher than the boiling point of the reaction system, under this temperature response of 10 min, the conversion rate of asarinin can reached at maximum. Hydrochloric acid-ferric trichloride synergistic catalytic mechanism study shows that:the benzylic protons of sesamol under the effect of FeCl3, making the chiral center racemized, protons are more easily to combine with carbon anion, which occurred in the chiral flip get asarinin. Calculated by the semi-empirical PM3 quantum chemical method, heat of formation of sesamin is higher 9.71 kJ·mol-1 than asarinin, sesame is more stability. The activation energy of the reaction system was reduced effectively after the addition of the composite catalyst, which accelerated the sesamin isomerization process for asarinin.The refining at acid condition makes the sesame lignans and its derivatives increase, improve the oxidation stability, and has the superior ability of scavenging free radicals. Using 2BS cells and skin absorption observed, after high temperature clay bleaching (sample AD-d, and E-AD-d, BD-d, and E-BD-d, see the appendix) of four kinds of sesame oils in total antioxidant capacity, reduce the content of MDA and SOD activity enhancement is higher than the blank control group. Which, the E-AD-d and E-BD-d shows superior to control group anti-aging of olive oil and antioxidant capacity, absorbed through the skin or feeding way, sesame oil shows strong delaying cell aging ability.Sesame lignans and its derivatives mixture in the experimental mice have antioxidant properties, and the D-galactose induced aging mice, sesamol, sesamin and asarinin all show better protection, sesame lignans has the strongest effect in cold pressed of sesame oil, dissection observed in mouse liver enlargement is restrained; High (120 mg·kg-1d-1), medium (60 mg·kg-1·d-1), low (30 mg·kg-1d-1) dose can significantly inhibit experimental mice liver MDA content increased, the most significant effect of LC group feeding; LB group to improve the experimental rats blood and liver GSH-PX activity ability best. For the LC group in improving the ability of T-SOD in the liver of the experimental rat is the best.Simulated physiological conditions in Britton-Robison buffer (pH=7.4), the UV absorption spectroscopy, circular dichroism (CD) spectroscopy, DNA thermal denaturation method and method of viscosity, sesamol, sesamin and asarinin and calf thymus ctDNA interaction mechanism are discussed. The results showed that ctDNA can make sesamol, sesamin and asarinin hypochromic effect at 290 nm absorption peak, and accompanied by a slight red shift phenomenon, ctDNA concentration, the greater the hypochromic effect more apparent, the combination constants of sesamol, sesamin and asarinin and ctDNA were 2.65×104、91x104.33×104 M-1; Three kinds of active substance can make ctDNA positive CD band (276 nm) increased, the negative CD band (246 nm) slightly decreased with the increase of the concentration of the more obvious; three kinds of active matter exists, ctDNA melting point were increased by 1.750℃,2.51℃ and 6.63℃, ctDNA viscosity was also increased.Comprehensive spectroscopy and viscosity of the experimental results, the three kinds of activity with DNA interaction in classic insert way, strength of effect size:asarinin> sesamin> sesamol. |
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