The microwave-assisted extraction of inulin from Dahlia Sp. tubers in water

Abstract

The Inulin is well-known as a valuable chemical since its structure contains fructose and glucose. Through extraction, inulin can be derived from Dahlia Sp. Tubers. Mostly, the acid and high temperature are used conventionally to extraction inulin from tubers. Instead of using acid and conventional hydrolysis, water and microwave-assisted extraction show promising. In term of the feasibility of the process, Dahlia Sp tubers are attractive alternative inulin feedstock as Dahlia Sp. tubers are abundant and cheap. This work is to find the optimum condition of inulin extraction in the aqueous medium based on the kinetic aspect. The Dahlia tuber powder was poured into microwave tubes filled with Milli-Q water in room temperature. Subsequently, the aqueous solution was added. Some tubes were located in a particular rack in the microwave reactor which was run on fixed temperature. The reaction time is in the range of 0-60 minutes. At diverse extraction times, a tube was withdrawn from the microwave reactor and speedily cooled down by the system to terminate the reaction. The reaction mixture was pipetted out, then the liquid product was separated from the mixture by centrifugation around 5-10 minutes. To identify and quantify, the liquid product was diluted then injected into vials to be analyzed with HPLC. A MALDI-TOF apparatus was also employed to identify the inulin structure. Variables investigated are temperature, loading concentration and reaction time. It can be concluded that (1) the optimum condition was influenced by temperature, loading concentration and reaction time; (2) the optimum condition providing the highest yield of 98.96 mole% was achieved at temperature reaction was 50 o C, loading concentration was 0,1 g/mL and reaction time was 50 minutes.