Enforcement And Investigation Of The Influences Of Gum Arabic On The Physicochemical Properties Of Konjac Glucomannan Solutions And Its Derivatives

The aim of this study was to investigate the influence of GA on KGM natural properties. The main research contents and conclusions were presented as follows.The apparent viscosity of KGM aqueous solution showed a progressive decreasing with the increase of GA concentration in the solution. Thus the hydrocolloids have reacted and GA reduced the capacity of KGM to swell and absorb water. The rheological behavior of KGM/GA blending also went from a no Newtonian to Newtonian system solution according to amount of GA in the solution.GA exhibited a Newtonian behavior, which affected the no Newtonian system of pure KGM. To have more information about the reaction in aqueous solution, the two polymers were subjected to molecular simulation study.The molecular dynamics simulation showed that the most important interaction relayed on the hydrogen bond. Pure KGM made much hydrogen links with water without any hydrogen links between its own molecules. In contrary GA made enough hydrogen links from its own main chain and in the other side with water molecule. In a mixture the molecular dynamics simulation showed that the presence of GA reduced significantly the hydrogen links from the KGM. Thus the reduction of hydrogen links is the main reason for the decreasing viscosity and natural properties of KGM. And this is mentioned on geometrical average by an unstable solution according to the potential energy.Water vapor permeation results showed the edible films derivate from the blend are sensitive to water vapor compared to the films made from pure KGM. The FT-IR confirmed that the modification occurred during films processing by the absorption of H while the functional groups remained less effect by the presence of GA. However the pure GA and pure KGM curves showed a very significant different that confirmed the high difference of their composition, structure and properties in aqueous solution. The DSC mentioned that at high concentration the GA reduced the thermal stability of blend films while at low concentration the hydrogen links showed an improved stability. At the same time the mechanical properties of the films were better with less GA content. The GA affected the extensibility and the breaking stress. In addition the application in Chinese noodle showed the same mechanical properties. However the high concentration of KGM affects negatively the hardness with high extensibility. The blending with2.5g GA and2.5g KGM showed the best results. The hardness, chewiness and the gumminess seemed to be acceptable according to the eating quality. The water up taken increased with decreasing the GA content. And the cooking loss remained important with KGM at2.5g. Compared to the blank the GA decreased the water up taken while KGM increased it.