The Effect of Ultrasonic Pretreatment on Inulin Extraction from Jerusalem Artichoke Tuber

Abstract

Abstract

This research was conducted to investigate the effect of pretreatment using high-power ultrasonicwave (750 W) at the sound frequency of 20 kHz on the extraction efficiency of inulin from Jerusalemartichoke tuber. Pretreatments were performed using various ultrasound wave amplitudes (20, 40, 60, 80and 100%), pretreatment times (1, 5 and 10 min) and pretreatment temperatures (25 and 80 °C). This wasfollowed by hot-water extraction at 80 °C for 1 h. The Jerusalem artichoke tuber powder to water ratiowas 1:50 by weight. Results showed that without the pretreatment the inulin extraction yield was only49.8% (dry weight). Pretreatment using ultrasound at every condition increased the extraction yield and thepretreatments at 80 °C resulted in higher extraction yields than the pretreatments at 25 °C. However, HPLCanalysis of carbohydrate components revealed that the ultrasonic pretreatment resulted in higher mono- anddi-saccharides ratio, which suggested that the ultrasound pretreatment was able to promote depolymerizationof inulin chain.

Keywords : Carbohydrate; Extraction efficiency; Fructan; ltrasonic wave