关键词: 魔芋多糖, 稀溶液, 魔芋茶汤, 流变特性

Abstract: The results measured and analyzed by a rheometer and Ubbelodhe typ e viscosimete have showed that:(1)The flow curves of sol of KGMdispersed in water and konjac-tea infosions approximated to non-Newtonian behavior and even show e d pseudo-plastic behavior at a KGM concentration of 0.100%or more in the dil ut ions.The n value of the dilutions of KGM were 0.9388,0.8897,and 0.7229at the con tents of 0.100%,0.150%,and 0.200%respectively, and the k values were 1.18 9×1 0-2, 2.778×10-2and1.583×10-1,respectively.But the n value of the konj ac-black tea dilutions were 0.9584,0.9554,and 0.9048at the content of 0.100%, 0.150 %,and 0.200%,and the k value were 5.851×10-3, 9.75×10-3and 2.824×1 0-2 ,respectively .(1)However,the flow curves of 0.075and 0.050%dilutions of K GM an d konjac-black tea approximated to Newtonian behavior.As it was previousl y the flow curves of 0.075and solution of KGM was a non-Newtonian fluid,the re sults in the present research indicated that the traditional conclusions could not ful ly explain the behavior of all dilutions of KGM .(2)The results also sho wed that the konjac-tea infusions without sugar-citric acid flowed easier tha n dilutio ns of KGM at the same content of KGM, so its flow curves obviously app roximated to Newtonian behavior.(3)The thixotropic viscosity of sugar-free kon jac-tea d rink was lower than that of dilutions of KGM dispersed in water at th e same cont ent of KGM.It was apparent that that a small change in temperature o f the KGM di spersion could result in a large variation in viscosity;and the app arent activat ion energy(E)of konjac-teadrink was estimated from he Arrhenius p lot as only 1. 0737 kcal/mol,indicating that the physical state of the dispersed KGMin and dilu te regime was quite susceptible to temperature change.

Key words: KGM konjac glucomannan, dilutions, konjac-tea extracts, rheological properties