Study On Rheological Properties Of Locust Bean Gum And Its Complex Gums

Locust bean gum (LBG) was a kind of natural galaetomannans which was extractedfrom the papilionaceae robinia black locust (Robinia pseudoacacia L). It had greatproperties of transparency, swellability and thickening and had some disadvantageswhich set limits to its uses, such as low viscosity and can not be formed as gel.Complex (blending) modification had been a convenient and important way ofdeveloping new materials in food industries. Complex could make varies single foodgums express the function of complementary in order to extend the usable range orimprove the usable properties for food gums. Moreover, the Synergy in food gums couldincrease the rheological properties of foods, improve the quality of food productsand reduce production costs.This study not only acquired a kind of complex gums which own the Synergy, basingon the material---LBG, by the way of complex from food gums such as Xanthan gum (XTG),Carrageenan (CAS) and so on, but also studied the interaction of molecules in LBGand different complex gums in the rheological method. The research provided moretechnical supports for the uses of complex gums in food industries and medicinefields and new usable ways for these food gums.Our results were appended below:1. The study on rheological properties of LBG.The results of rheological properties of LBG showed: LBG wass a kind ofNon-Newtonian fluid, it belong to the Thixotropic fluid in the Pseudoplastic fluid.The thermostability of LBG was good below80℃, and its viscosity increased withthe increase of concentration. Only a part was dissolved in cold water, and it hadlow viscosity. It could all be dissolved after a thermal treatment of80℃, and itchanged to a kind of viscous fluid which became most viscous after cooling. It hada strong pH stability for the almost unchangeable viscosity under the PH conditionof3to9. The ultrasonic treatment which was under60%power and within15min didnot has obvious influence for its viscosity. The refrigerated influence forviscosity was more than the frozen, so the refrigerated way was not good for thegums store. Barium salts could increase more G’, G’’ and η*of LBG than sodiumsalts, especially the BaCl2comes firstly. LBG had a strong ability of salt-tolerant, the20%NaCl had a little influence in the viscosity reducing extent. Its flow curvehad a high degree of fitting with Cross model, and the R2could be more than0.99.The degree of fitting with Carreau was higher than the Ostwald’s, but lower thanCross’.2. The study on the rheological properties of mixing LBG with others food gums.The rheological properties results of the complex gums for LBG and others foodgums such as Xanthan gum (XTG), Carrageenan (CAS), Guar gum (GG), Sodium alginate(AGS), Konjac gum (KGM) and Tamarind gum (TSP) showed: The complex of LBG with XTG,CAS and GG could effect the Synergy of "1+1﹥2", it of LBG with AGS could effectthe Synergy of "1﹤1+1﹤2", and it of LBG with KGM and TSP could had the anti-cakingeffect of "1+1﹤1".The best compound proportion of LBG and XTG was4/6, it of LBGand CAS was4/6, and it of LBG and GG was1/9. LBG and XTG at4/6’s viscosity increasesby the increased concentration; The maximum viscosity was gained under the conditionof being in the80℃hot water for60min; The pH value of solution was almost stablebetween6and10.The salt ions influence for complex modulus was KCl （nearlynon-influence)＜NaCl＜CaCl2＜AlCl3.3. The study on the complex gums of LBG effects on lappaconitine releasedproperty and hydroquinone adsorbability.The results showed: Drug release of the LX46and LC46-carriers membrane wasconsistent with the increase of drug. Drug cumulative release was10mg drug loading>20mg drug loading>50mg drug loading. As the drug loading was10mg, the accumulationof drug release of LX46-lappaconitine film was81.1%at pH=6.8, and theLC46-lappaconitine film was86.3%. pH similar impacts on the the two carrier films’drug release. pH=2.0and4.0, lappaconitine of the two carrier films was essentiallycomplete released in a short period of time, and release rates were more than95%;pH=9.0and11.0, the lappaconitine’s release rates of the two carrier films werebelow40%at240mins. The proportion of complex gums, the time of oscillation andthe pH value of systems could affect the adsorbability of hydroquinone. In allLBG/CAS films and LBG/XTG films，the LC46film and LX46film have the best abilityfor adsorption, and their clearance rates were77.5%and81.58%, and the LX46filmshowed better ability for adsorbing number and acidproof. The compound films were the natural macromolecular polysaccharide films, which had the properties ofnontoxicity, compatibility, strong safty and were used for medical field.