Characterisation of different inulin samples by DSC - Influence of polymerisation degree on melting temperature

Melting behaviour of powder inulin has been studied by differential scanning calorimetry. DSC curves show two endothermic peaks, relative to water elimination and to inulin melting, respectively. The second peak is dependent on inulin type and a shift to a higher temperature is observed with increasing average polymerisation degree (DP) of the sample. For similar crystallinity index, linear relations have been underlined and so predicting inulin mean DP can be done by DSC analysis. The study shows that a relatively high heating rate (25degreesC min(-1)) can be used and brings a supplementary interest by an important reduction of analysis time.