Comperation of Porang Flour (morphophallus muelleri) Purification Method : Conventional Maceration (gradient ethanol leaching) and Ultrasonic Maceration Method using Response Surface Methodology

Abstract

Porang flour (Amorphophallus muelleri) contained fairly high of glucomannan and slightly orange white colour whereas also contained oxalates which are toxic to human. This toxic property caused unacceptable for food applications. This systematic study was undertaken to compare two of the optimizations method of flour porang purification i.e. using various of ethanol concentration washing (conventional maceration) and ultrasonic maceration method to obtain high glucomannan levels and high viscosity with low calcium oxalate and bright white colour of flour. Response surface methodology (RSM), Central Composite Design (CCD) on three independent variables (leaching time (X1), stirring speed (X2) and the ratio of solvent to flour (X3))  for the conventional maceration and two independent variables ( time leaching (X1) and and the ratio of solvent to flour (X2)) for ultrasonic maceration, has been done. Response analyzed on glucomannan levels, viscosity, concentration of calcium oxalate, and brightness. Response has a quadratic model except the brightness of the colours of the linear model in both maceration. The ultrasonic maceration obtained faster washing time i.e. 3 hours, 53 minutes and 18 compare than the conventional maceration and used more less solvent and get a high levels of glucomannan response values , viscosity values , well white brightness colour and a low levels of oxalic acid value.