COMPARISON OF HOT AIR AND SUPERHEATED STEAM DRYING OF JERUSALEM ARTICHOKE (HELIANTHUS TUBEROSUS L.) TUBERS AND INULIN POWDER PRODUCTION

摘要

Jerusalem artichoke tubers (JAT) are rich in inulin, which can be used in food as a prebiotic and dietary fiber supplement. In this study, hot air drying and superheated steam drying of JAT were compared. The hot air drying was carried out at 55 degrees C, 65 degrees C, and 75 degrees C, while the superheated steam drying temperatures were 120 degrees C, 140 degrees C, and 160 degrees C. JAT samples from a selected drying condition were used for manufacturing JAT powder and inulin powder by applying an extraction process. The aims of this research were to (1) compare the quality of blanched and unblanched JAT dried under different conditions in terms of moisture content, color, and microstructure, (2) investigate the drying kinetics of JAT during hot air and superheated steam drying, and (3) determine the chemical compositions of JAT powder and inulin extracted from JAT powder. The result indicated that superheated steam drying was inappropriate for JAT due to the excessive drying time and unacceptable product color. For hot air drying, Page's model and the Modilli et al. model were the best-fitting models due to their high R-2 and low RMSE values, while the effective moisture diffusivity (D-eff) ranged from 1.56 x 10(-10) to 3.14 x 10(-10) m(2) s(-1). Additionally, the extraction process applied in this work increased the inulin content from 39.09 g per 100 g (d.b.) in JAT powder sample to 56.29 g per 100 g (d.b.) in inulin powder sample.