Effect of Drying Air Temperature on Drying Kinetics Parameters and Fructan Content in Helianthustuberosus and Cichoriumintybus

Abstract

Helianthus tuberosus and Cichorium intybus tubers accumulate fructans, non-digestible fiber, which has attracted great interest recently as a functional food. In this work a mathematical model for describing the tray drying of the tubers is proposed. It was found that the drying rate in the constant drying rate period was a function of the drying air temperature. Calculated values of the effective diffusivity coefficient are of the magnitude order of 10⁻⁹ m²/s; for both tubers the value of this parameter depends on the drying temperature. Drying affects the fructan molecular weight distribution and fructose content in H. tuberosus and C. intybus tubers. These changes are dependent on the drying air temperature.

Keywords:

• Tubers drying
• Sugar content
• Molecular weight distribution
• Tray dryer
• Effective diffusivity

Acknowledgments

The authors wish to thank the economical support given by Conicyt through projects Fondef D99 I 1025 and Fondecyt 1000344.