Innovative valorization of date seed extract: extraction, optimization and characterization for sustainable sugar production

Date seeds are an abundant agro-industrial by-product that remains underutilized despite their potential as a source of valuable compounds. However, limited studies have explored their valorization as a source of natural sugars and bioactive compounds using optimized extraction processes. Therefore, this study aimed to develop a sustainable approach for the valorization of Kentichi date seeds by producing value-added extracts from Kentichi date seed powder (KDSP) using Response Surface Methodology (RSM). This approach contributes to reducing agro-industrial waste while promoting the recovery of valuable compounds. The optimized extraction conditions were a powder/solvent ratio of 200 g/L, an extraction temperature of 30 °C, and an extraction time of 6 h, resulting in an extraction yield close to the model-predicted value (77.87%). The developed model was statistically significant (p < 0.0001) with a high coefficient of determination (R² = 0.92; adjusted R² = 0.89). The obtained Kentichi date seed powder extract (KDSPE) contained 18.6 g/L of total sugars and 9.75 g/L of proteins. The extract also showed high levels of phenolic compounds (9050 µg GAE/mL), contributing to strong antioxidant activity (DPPH IC₅₀ = 10 µg/mL; ABTS IC₅₀ = 6 µg/mL). Freeze-drying proved effective for producing KDSPE powder while preserving its bioactive properties, highlighting its potential as a promising ingredient for future food applications.