This work is a contribution to the valorization of the Algerian date palm agrobiodiversity by studying some nutraceutical properties of date pastes from less important cultivars. A commercial date paste, prepared from Ghars variety, was compared to two date pastes prepared from the secondary cultivars Tamjouhert and Tazarzeit. Physico-chemical characteristics, phenolic profile (HPLC-DAD), and antioxidant activity were assessed for both date fruits and pastes. The sensory evaluation of date pastes was conducted through triangular, ranking, and hedonic tests. The results revealed that the transformation of date fruits into pastes caused a significant increase in phenolic content and antioxidant capacity, a decrease in sugar content in parallel with the appearance of hydroxymethylfurfural and furfural. The elaborated date pastes were characterized by a relatively low level of sugar (72.17–74.14 mg/100 g), a high amount of phenolic compounds (> 290 mg/kg DW), and a potent antioxidant activity. Seventeen phenolic compounds were identified by HPLC with global quantities for date fruits of 113 (Tamjouhert cv.) and 100 mg/kg DW (Tazarzeit cv.) and that were increased twofold after transformation to date pastes. The sensory analysis for the obtained date pastes indicated high scores of acceptability in comparison with the commercial paste. The obtained results showed clearly that these secondary cultivars possess several potentialities; this may help to valorize them by turning a part of their production into several added-value products such as date past.