Influence of germination on the production of starchy and oleaginous flours: Evaluation of the drying process, thermodynamic properties and bioactive compounds

Chickpea and lentil seeds, rich in starch and protein, and sunflower and linseed, known for their high lipid content, are globally valued for their nutritional properties. Germination enhances their nutritional value but increases water activity, making them perishable. Drying reduces water content, improving stability and concentrating nutrients. This study analyzed the drying kinetics and thermodynamic properties of germinated starchy seeds (chickpea and lentil) and oilseeds (sunflower and linseed) at 50, 60, and 70°C. The two-term model best fitted the drying data, with effective diffusivities increasing with temperature. Activation energies ranged from 13.66 kJ/mol (chickpea) to 29.61 kJ/mol (sunflower). Positive enthalpy values indicated a non-spontaneous process driven by temperature, while Gibbs free energy increased with temperature. Lentil and chickpea flours achieved optimal moisture levels for storage. Germinated seed flours showed increased carotenoid content and a positive correlation between phenolic compounds and antioxidant activity. A negative correlation was observed between tannins and carotenoids, as controlled germination and drying reduced tannins, improving nutritional quality by decreasing antinutritional factors.