Make a 5 Keyword, The Application of Natural Deep Eutectic Solvents (Betaine-Glycerol) for Isolating Glucomannan from Porang Flour (Amorphophallus muelleri Blume)

Abstract

Porang tuber (Amorphophallus muelleri Blume) contains a high amount of glucomannan, an indigestible dietary fiber. Glucomannan is generally isolated using ethanol. To overcome competition with food and feed in the production of bioethanol, it is proposed to use Natural Deep Eutectic Solvents (NADES) for isolating glucomannan. This study evaluated the application of NADES and ethanol to isolate glucomannan from porang flour. The NADES was prepared by mixing betaine and glycerol in different mole ratios. (1:1, 1:2, and 1:3). The result showed that the obtained glucomannan flour ranged from 74.36% to 77.40%. Results indicated that the glucomannan content of glucomannan flour isolated by NADES was lower than that of ethanol. However, glucomannan flour isolated by NADES showed brighter color than that produced by ethanol. The rheological result indicated that the gel of glucomannan flour (1% w/v in water) exhibited pseudoplastic behavior. NADES (betaine and glycerol with a mole ratio of 1:2) was found to be the most effective formula to isolate glucomannan from porang flour compared to the other mole ratios with glucomannan content, viscosity, and whiteness index of 86.78% (dry base), 17,680 cP, and 75.62, respectively.