Biofortification by Co₂ Stress: Effects on Germination and Bioactive Compounds of Chickpeas (Cicer Arietinum L.)

Abstract

The effect of high concentrations of carbon dioxide (CO2), imbibition and germination time in chickpea seeds was investigated, focusing on their germinative capacity, radicle development, nutritional composition, non-nutritional composition, and phytochemical profile at different time points, also evaluating the antioxidant and chelating capacity throughout the germination process. Evaluation of different imbibition and germination times determined that optimal conditions included 60 min of soaking and a temperature of 28 ± 1 °C, with a relative humidity of 45-65% and a light/dark cycle of 12 h. Two concentrations of CO₂ were tested in the presence of oxygen. Seeds exposed to high CO₂ concentrations (740-760 ppm) showed faster germination, higher germination percentages, and better root development compared to seeds germinated at ambient CO₂ concentrations (400-420 ppm). Throughout the germination process, total phenolic compounds, particularly flavonoids, showed a significant increase. This increase was positively correlated with antioxidant activity, reaching peak levels nine days after germination. These findings suggest that increased CO2 in the presence of oxygen enhances the production of secondary metabolites in sprouted chickpeas, which boosts antioxidant activity and could result in important nutritional and health benefits for consumers.

Keywords: Chickpea, germination, Imbibition, Carbon dioxide, phytochemical profile, phenolic compounds, Antioxidant