Studies On The Brier Grape (Vitis Davidii Fo(?)x.) Skin Pigment

"Health" is becoming the most popular concern.So it has far-reaching significance in realism and expansive foreground in appliance to develop functional products from botanical resources for human being's health through the studing on physiologically active ingredient in natural plants.In this case,the developing and utilizing of natural pigments,especially anthocyanin pigments from plants is becoming one of the research hotspot at present.Being the natural edible pigments and antioxidants,anthocyanins is widely distributing in the flowers,leaves and fruits of plants.Because of its safety and nontoxicity,but of its nutritional and the pharmacological functions,anthocyanins is being paid more and more attention on by food industry,medical industry and consumers,thus it has huge potential in appliance.Brier grape(Vitis davidii Fo(e|¨)x.)grew in China originally,and distributed in Shanxi, Gansu,the central China,southern,and south-western China.The yield is increasing in recent years from the north-western mountainous area and south area in Hunan province. Vitis skin has abundant anthocyanins which is very thick and deep in colour,and it's rich in resource and low in price as the inedible part of fruit and the by-poducts of Vitis.So,it's really a kind of natural edible pigments resource which is developable.This excellent resource hasn't been utilized yet,however,because of the lacking of enough technology.The systemic study on Vitis skin pigment will be helpful not only to the developing and utilizing of this resource more timely,reasonable,effective and comprehensive,but also to the enlaging cultivation and improving on the regional agriculture structure which results in the increase of farmers' income.In this thesis,the content of Vitis skin anthocyanins(VSA)was determined on the basis of selecting of mensuration.Through the design of quadratic rotational combination test and Multiple regression analysis,the parameters of the extraction technics of Vitis skin pigment(VSP)were optimized.The stability of VSP in food circumstances was studied, and the thermal degradation kinetics of VSA was also investigated.The most suitable macroporous resin to purify the VSP was screened out,and on this basis,the parameters of static and dynamatic absorption/desorption technics for purifing VSP were established.This article also studied the isolation technics of VSA by using several methods such as TLC, CC,HPLC,etc.Ultraviolet-visible spectrum,HPLC-MS,IR,and NMR were applied to identify the molecular structure of VSA.The results showed that:1.Vitis skin contained high amount of anthocyanins(2.5227mg/g FW),its colour-value was 2.43,2.87,and 21.75 times to that of Chixiazhu,Hongti,and Jufeng grape respectively. 2.70%aqueous ethanol+0.03%HCl was suitable extractant of pigment from dry Vitis skin powder,and the single factors as followed were most suitable for extracting VSP:50℃as extraction temperature,1:15 as the ratio of Vitis skin to extractant,60min as extraction time. Through the design of quadratic rotational combination test and Multiple regression analysis,the established regression model relating to extraction yield of VSP indicated that the optimized condition of the response surface model(RSM)was ajustied as 47℃,70min, and 1:17 to practical production.The demonstration tests on optimum condition of RSM showed that the regression model had significant optimization effect and precise prediction. On the other hand,during extracting pigment from fresh Vitis skin,distilled water (+0.5%acetic acid)was suitable extractant,and the single factors as followed were most suitable:50℃as extraction temperature,1:15 as the ratio of Vitis skin to extractant, 60min as extraction time.The optimized condition of the RSM was ajustied as 45℃, 128min,and 1:13 to practical production.3.Value of pH was a significant factor on the stability of VSP,and VSP should be used under acidic circumstances.The sunlight accelerated the degradation of VSA.Ascorbic Acid and H_2O2 enhanced the fading of VSP solution;Sodium sulfite led to fade of colour of VSP solution;Low concentration of Benzoic Acid and Potassium sorbate(≤0.5g/L)had little influence on the stability of VSP.Mg²⁺,Mn²⁺and K⁺ lowed the absorbency of VSP slightly; Zn²⁺and Ca²⁺had copigmentation effect on VSP solution;Al³⁺and Cu²⁺added the absorbency of VSP;Fe³⁺caused dark-brown precipitate in VSP solution and made it not be anthocyanin any more.Sucrose,glucose and salt had all copigmentation function,and the effects of copigmentation were related to the concentration of these copigment.The enhancement effects of organic acids on the absorbency of VSP were in following order: oxalic acid>citric acid>lactic acid>gallic acid>boric acid.4.It was proved that the thermal degradation of VSA was accordant with the first-level reaction equation of kinetics.At the same pH,the half life of VSA could be prolonged remarkably with the falling of temperature;at different pH,the activation energy(E_a) needed for the degradation of VSA was ordered as E_a(pH1.0)>E_a(pH3.0)>E_a(pH4.5). This result explained that lower pH was more helpful to the preservation of VSA when heating,but the hydrolization of pH1.0 VSA which occurred at very high temperatures (>80℃)should be paid more attention to.5.The macroporous resin HP-20 was the most suitable sorbent among the macroporous resins be tested. Under the optimum condition of static adsorption,that was 40℃and pH3.0,the saturation adsorption was 32.0796mg/g(pigment solution 1.2357mg/mL,in terms of GSP),and the best desorption solvent was 80%ethonal(+0.05%HC1).The optimized parameters of dynamic adsorption/desorption were chosen as follow:pigment solution 1.5891～3.1377mg/mL; velocity of pigment solution flow 4.5BV/h;the volume and velocity of desorption solvent 8 BV,3 BV/h.Under the condition mentioned above,the saturation adsorption of HP-20 to VSP was 39.00mg/mL wet resin,and the desorption ratio was more than 92%,the colour value of purified pigment was 5.93 times to that of unpurified.6.After systemic column chromatography separation(HP-20 macroporous resin,polyamide, Sephadex LH-20),the leading anthocyanin monomer AN1 was obtained and its purity was over 95%(the content of AN1 in VSA was 85.805%).The result of structure identification combining UV-vis,HPLC-MS,IR and NMR indicated that AN1 is malvidin-3,5-glucose-coumarate.According to the results of UV-vis and HPLC-MS,the two other anthocyanins AN2 and AN3 from VSA were identified as peonidin-3,5-diglucose and malvidin-3,5-diglucose respectively.