Thermal properties of ambient ground fenugreek (Trigonella foenum- graceum L.)

The present investigation was done to study the thermal properties, namely, thermal conductivity, specific heat and thermal diffusivity, as a function of temperature. These properties were determined for ambient ground (30°C) fenugreek powder of following varieties viz., AM, RMT- 305 and RMT-1 for temperature range from -30°C to 30°C. Thermal conductivity was evaluated using thermal conductivity meter, specific heat by differential scanning calorimeter and bulk thermal diffusivity by standard relation. It was found that thermal conductivity increased with the increase in temperature from -30°C to 30°C, thus depicting a direct correlation between the two. Also the overall specific heat of the spice varieties decreased initially from -30°C to 10°C and then increased from temperature 20°C to 30°C. Thermal diffusivity showed an increasing trend with the increasing temperature for all the three varieties. Mathematical modelling of thermal properties as a function of temperature resulted in polynomial expressions, mainly of sixth order, which may be applicable for easy fabrication of ambient grinding system, for spices and development of advanced grinding systems, conserving the essential spice properties