The extraction and characterization of inulin from dahlia bulbs (Dahlia variabilis)

Abstract

One of plants with tubers that is rich of Inulin is well known as Dahlia. Inulin obtained in Dahlia is consisted of fructose monomers which are natural polymers and are linked by linear -2,1-fructosyl-fructose bonds. The aim of this study was to extract inulin from dahlia tubers, determine the moisture content and degree of purity of inulin from dahlia tubers. This study was conducted experimentally at the Research Laboratory of STIKes Payung Negeri Pekanbaru and STIFAR Riau. Inulin was characterized qualitatively and quantitatively including the Seliwanof test, determination of water content (Moisture Balance method), determination of inulin yield and determination of the degree of purity of inulin using High Performance Liquid Chromatography (HPLC). The object of this study was the ornamental dahlia plant obtained from Bukittinggi, West Sumatra. Dahlia bulb extraction results obtained inulin yield of 0.47% (w/w) with a yellowish white color. Qualitative test with Seliwanoff's reagent showed positive results indicated by the formation of a red color which indicated that inulin was positive for fructose. The research results indicated that the content of water percent dry weight (bk) of inulin itself was 4.53%. Quantitative analysis was performed using HPLC at a wavelength of 210 nm. The HPLC chromatogram showed that dahlia tubers had an inulin content of 84.08%, lower than the commercial inulin of Chicory Merck Orafti®GR. Moreover need further research and analysis using Gas Cromatography (GC) so that the degree of inulin polymerization can be determined.