Modeling the gelatinization-melting transition of the starch-water system in pulses (lentil, bean and chickpea)

Cooking-induced conversion of starch, the major carbohydrate in pulses, is crucial for the digestibility of the seed. The gelatinization-melting transition of lentil, bean and chickpea starches was studied using Differential Scanning Calorimetry at different temperatures (T values ranged from 20 to 160 ?C) and water contents (X from 0.2 to 3 kg kg? 1 db). Gelatinization and melting endotherms were successfully modeled as two desummed Gaussian functions. This modeling enabled to generate the degree of starch conversion for any T and X conditions, a valuable indicator that could be used in predictive cooking models. As previously reported for melting, the temperature of gelatinization was found to depend on moisture in a way that can be modeled using the FloryHuggins equation. The results suggest that starch undergoes melting transition irrespective of water content. The similar starch conversion diagram for the three pulses suggest that starches have similar thermal behavior.

Automated summary

The study analyzed gelatinization-melting transition of lentil, bean, and chickpea starches at different temperatures and water contents. Results showed that starch conversion could be predicted, with gelatinization and melting temperatures influenced by moisture, and similar thermal behavior of starches among the three pulses.