Konjac glucomannan(KGM)was aminated by 2-chloroethyl-amine(CEA)as reagent so as to study the influence of concentration of CEA(based on the amount of KGM),concentration of NaOH,reaction time and temperature on the extent of amination.And the molecular simulation technology was adopted to analyze the conformation stability of aminate(AKGM).The results indicate that when the amount of CEA is higher,the extent of amination is higher.The optimum concentration of NaOH,reaction time and temperature are 10%NaOH,70℃and 45 min,respectively.IR shows KGM is successfully aminated.The conformation of AKGM is in a random clew-like shape.
WANG Li-XiaWEN Cheng-RongWU JingLIN Hai-DongHU Shu-GuoPANG Jie
To understand the effect of plasma treatment on the Konjac glucomannan film, the nitrogen plasma was injected into the film by ion beam injection machine in this study. The structures and properties of Konjac glucomannan film after plasma treatment were analyzed by Infrared spectroscopy, Raman spectrum, X-ray, ect. The result showed that nitrogen groups appeared in the KGM molecular chain and part of this chain fractured, and the number of hydrogen bonds increased after the treatment of plasma. The form of KGM molecule remained amorphous non-crystalline state, but the crystalline region was increased and became more ordered. The mechanical property of tensile strength and breaking elongation was improved, while the WVP was decreased. The nitrogen groups were grafted on the KGM molecular chain after plasma treatment, which led to the improvement of the properties of KGM film.
The local maxima of water density in the space near the single-helical of Konjac glucomannan as well as the dominant conformation of the system was studied by molecular dyna-mics under the water environment. The results indicate that the hydration shell,potential energy,and its hydrogen bond network with water bridges of the left-handed single-helix conformation was favored compared to those of right-handed single-helix conformation. This work suggests that the left-handed single-helix conformation was the dominant conformation of KGM in the water environment.
Biological activity of konjac glucomannan is closely related to its structure,in particular to its high-level structure.Researches on the activity mechanism of konjac glucomannan are significant for revealing the mysteries of participation in life activity.In this paper,analysis of the effects of konjac glucomannan configuration and various factors on its structure and activity was conducted,mechanism of biological activity of konjac glucomannan was explored,and the hot research topic of konjac glucomannan was given.
The local maxima of water density in the space near the single-helical of Konjac glucomannan,as well as the do...
Jie PANG 1,Wenjie JIAN 1,2,Minna YAO 1,Huimin LIN 1,Aijun FENG 1,Yuan ZENG 1 (1 College of Food Science,Fujian Agriculture and Forestry University,Fuzhou 350002,China
Structures of KGM treated in two high-voltage pulse electric fields were characterized by infrared spectroscopy,Raman spectroscopy,X-ray diffraction and so on.The results showed that intermolecular hydrogen bonding interactions of KGM were reduced after being treated with high-voltage pulse electric field,but there was no significant effect on its fiber chain form and thermal characteristics.Results of the study can provide a useful reference for further study on the structure and property of KGM,and especially can provide theoretical basis for the effect of physical field on the foodstuff deep processing related to KGM.
