Study On The Interaction Of Konjac Gum And Curdlan And Its Composite Gel Preparation

To improve the performance of konjac gel and develop the new konjac gel food,this article tries to use Konjac glucomannan(KGM)and Curdlan(CUD)as raw materials for the preparation of composite gel with good textural properties.The possibility of interaction between Konjac gum and Curdlan as well as the mechanism were researched by rheology and DSC.And on this basis,some process parameters on the performance of the gel,such as mixing time,alkali concentration,polysaccharides and starch concentration were discussed.Furthermore,central composite experiment and factor analysis were used to determine the optimal preparation of the composite gel.Then composite gel was added to jelly as a bionic fruity flesh and its storage stability was investigated,aiming to provide reference for the further application of Konjac gum and Curdlan in food.The major results of the study were as follows:1.Studies on the interaction between Konjac gum and CurdlanBecause of intermolecular interactions,there is good viscosity synergism between KGM and CUD,when they are blended under alkaline condition.When KGM is dominant in the system,with the increase of CUD proportion,storage modulus(G’)and loss modulus(G")of the mixed system are gradually decreased and the gel time of KGM is also extended during gelation process.Single KGM gel has a thinning phenomenon at low temperature and poor thermal stability relatively.The addition of CUD can help to improve its low-temperature resistance and heat resistance.When the KGM/CUD ratio is between 4:1 and 1:1,both of the blend compatibility,and gel properties are good relatively.2.Preparation of the composite gel of Konjac gum/CurdlanThe optimum process parameters are:KGM and CUD swelled for one hour at 50 ℃ water respectively.Then alkali is added in the system and stirred at 400r/min for 14min to blend.After that the blends are put in water at 90℃,bathed for one hour to gel.KGM:CUD is 8.3:1.7;the amount of sodium carbonate is 1.1%;the total polysaccharide concentration is 3.0%and the content of potato hydroxypropyl starch is 2.3%.With these process parameters,the composite gel has good chewiness,certain hardness and gel strength,and the water holding capacity is more than 91%,The composite gel can be used as bionic food,vegetarian and other basic raw material and has a certain value.3.Application of the Konjac gum/Curdlan composite gel in jellyThe single KGM gel as control group and KGM/CUD composite gel as bionic flesh were added into jelly respectively.Two gel weights both increased during storage,but the increment of the composite gel is greater than the single KGM gel basically.Water holding capacity,pH and moisture content of two gels would all decrease then maintain a constant,and whiteness would rise during storage.The textural properties of the two gels demonstrated relatively great different.The composite gel is homogeneous and more delicate,while single KGM gel texture is relatively rough but better chewiness.Furthermore,the addition of the two gels show little impact on the jelly sense values.