Effect of germination on the hygroscopicity, thermal stability and mineral composition of starchy and oilseed flours

This study provides a comparative and integrative evaluation of the stability and functional properties of flours produced from germinated seeds of starchy (chickpea and lentil) and oilseed (sunflower and flaxseed) species, highlighting how compositional differences influence their technological and nutritional potential. Hygroscopic behavior, thermal stability of phenolic compounds, and chemical composition were analyzed to elucidate their impact on flour performance. Adsorption isotherms fitted to the GAB model showed that starchy flours exhibited greater moisture retention, whereas oilseed flours showed reduced hygroscopicity due to their higher lipid content. The thermal degradation kinetics of total phenolics followed a zero-order model, with temperature significantly influencing degradation rates; based on the activation energy values, chickpea flour exhibited the greatest resistance to phenolic degradation, whereas flaxseed flour was the most susceptible to thermal degradation. Mineral analysis revealed that chickpea flour is rich in phosphorus and potassium, whereas flaxseed flour stands out for calcium and magnesium. Starchy flours presented higher total carbohydrate levels, while oilseed flours contained lower amounts of simple sugars, reinforcing their nutritional differences. Thermodynamic analysis showed that chickpea flour requires higher activation energy for phenolic degradation, suggesting greater stability, whereas flaxseed flour exhibited lower activation energy, indicating higher susceptibility. Overall, this study advances understanding of how germination and seed type modulate flour properties, with implications for developing functional food formulations with improved stability and nutritional quality.