Measurement of heat capacity for borage seeds by differential scanning calorimetry

Specific heat capacity of borage seeds was determined by differential scanning calorimetry (DSC) in the temperature range of 5 to 80C and moisture content range of 0.47 to 30.31% wet basis. The specific heat ranged from 0.57 to 2.48 kJ/kgK. A multiple regression model with interaction terms correlated well the specific heat to temperature (T) and moisture content (M). It was found that the interaction terms T*M and T*M-2 were significant (alpha = 0.01) and thus were included in the model, and the term M*T-2 was insignificant. Effect of measurement techniques with DSC were also investigated in this study to ensure that true specific heat values were obtained. Seal condition of the sample holders during DSC measurement had considerable effect on the specific heat of borage seeds. The difference between the specific hear of sealed and unsealed samples increased as seed moisture content increased, especially at higher temperatures. For the measurement of the specific heat of borage seeds by DSC in the above-mentioned temperature and moisture content ranges, an average of 5.75% deviation was found between the measurement with and without blank compensation.