title: Characteristics of glucomannan isolated from fresh tuber of Porang (Amorphophallus muelleri Blume).
abstract: Porang is a potential source of glucomannan. This research objective was to find a direct glucomannan isolation method from fresh porang corm to produce high purity glucomannan. Two isolation methods were performed. In first method, sample was water dissolved using Al2(SO4)3as flocculant for 15 (AA15) or 30 (AA30) minutes with purification. In second method, sample was repeatedly milled using ethanol as solvent and filtered for 5 (EtOH5) or 7 (EtOH7) times without purification. The characteristics of obtained glucomannan were compared to those of commercial porang flour (CPF) and purified konjac glucomannan (PKG). High purity (90.98%), viscosity (27,940 cps) and transparency (57.74%) of amorphous glucomannan were isolated by EtOH7. Ash and protein level significantly reduced to 0.57% and 0.31%, respectively, with no starch content. Water holding capacity (WHC) of EtOH7 glucomannan significantly enhanced, whereas its solubility was lower than those of PKG due to its ungrounded native granular form.
authors.affiliation: Department of Agricultural Technology, Sriwijaya University, Jl. Palembang Prabumulih Km. 32, Inderalaya, Ogan Ilir 30662, South Sumatra, Indonesia; Faculty of Agricultural Technology, Gadjah Mada University, Jl. Flora No.1, Yogyakarta 55281, Indonesia. Electronic address: annyyanuriati@fp.unsri.ac.id.
authors.forename: Anny
authors.initials: A
authors.lastname: Yanuriati
authors.affiliation: Faculty of Agricultural Technology, Gadjah Mada University, Jl. Flora No.1, Yogyakarta 55281, Indonesia.
authors.forename: Djagal Wiseso
authors.initials: DW
authors.lastname: Marseno
authors.affiliation: Chemical Engineering Department, Faculty of Engineering, Gadjah Mada University, Jl. Grafika No. 2, Yogyakarta 55281, Indonesia.
authors.lastname: Rochmadi
authors.affiliation: Faculty of Agricultural Technology, Gadjah Mada University, Jl. Flora No.1, Yogyakarta 55281, Indonesia.
authors.forename: Eni
authors.initials: E
authors.lastname: Harmayani
mesh_terms: D031056:Amorphophallus / Q000737:chemistry*; D005433:Flour; D008351:Mannans / Q000032:analysis*; D035281:Plant Tubers / Q000737:chemistry*; D014783:Viscosity
chemical_list: D008351:Mannans; C022901:(1-6)-alpha-glucomannan
keywords: Amorphophallus muelleri Blume; Characteristics; Fresh tuber; Glucomannan; Isolation; Porang