With the growing popularity of date seed brews and the potential impact of high and low molecular weight materials (HMw and LMw, respectively) on consistency, flavor, aroma and overall acceptability, this study aimed to isolate and characterize HMw and LMw fractions enriched with melanoidins from date seeds and compare their physicochemical properties to those of Robusta coffee. Two varieties of date seeds, Stamaran and Mazafati, were roasted, extracted with 70% ethanol, and fractionated into HMw and LMw materials. The results revealed that although HMw fractions of date seeds were rich in melanoidins, Robusta coffee contained significantly higher amount of melanoidins (7.86%) than date seeds (1.03–1.06%), when considering the mass of starting materials. The higher Kmix 405 nm observed in coffee brew (1.1142 L/g·cm) compared to date seed brews (0.6145–0.7813 L/g·cm) further supported the superior efficiency of melanoidins extraction in coffee. When comparing HMw fractions, the carbohydrate, total phenol, zeta potential, carbon-to-nitrogen ratio and Kmix 405 nm obtained from date seeds were higher than those observed in HMw of coffee. UV-Vis and FTIR spectroscopies also confirmed structural similarities within HMw fractions isolated from two varieties of date seeds, but they were different from those found in Robusta coffee. In summary, despite the high concentration of melanoidins in the HMw fractions of date seeds, the total melanoidins content in their brews was relatively low (0.64–0.68 mg/mL), which may affect consumer acceptance and preference, particularly in comparison to other melanoidins-rich beverages such as coffee brew. Therefore, to fully utilize the potential of date seeds in brew preparation, increasing extraction yield or blending with additional ingredients may be required.

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