Characteristics of Konjac Glucomannan (KGM) in <i>A.bulbifer</i> Compared with that in <i>A.rivieri</i> and <i>A.albus</i>

Abstract

Amorphophallus bulbifer (A. bulbifer) is a promising species in Amorphophallus sp., with great potentiality of developing, low risk for cultivation and considerable commercial benefits, mainly locates in tropical and subtropical regions or near the equator. Konjac glucomannan (KGM) is the main component of Amorphophallus tuber which is a water-soluble dietary fiber. In this work, some physiochemical properties of KGM in three Amorphophallus species flour [one was A.bulbifer, the other two were current main species namely Amorphophallus rivieri (A. rivieri) and Amorphophallus albus (A. albus)] were studied and compared with each other. The KGM content in A. rivieri, A. albus and A. bulbifer flour were 85.03%, 76.28% and 88.07% (w/w), respectively. The apparent viscosity, viscosity average molecular weight, whiteness, gel-forming properties and chemical structure of KGM in the three flours were investigated by using viscometer, colorimeter, texture analyzer and Fourier transform infrared (FT-IR) spectroscopy. The results indicated that the viscosity and Mw of A. bulbifer was the largest, gel strength was almost same (p>0.05) and the molecular structure were of no differences of three KGM. It may be proposed that transplanting A. bulbifer from its native land in the tropical and subtropical regions to temperate zone in the southwest part of China would be feasible, and it would cause the revolution of Amorphophallus sp. and more considerable benefits.