Roasted date and barley beans as an alternative?s coffee drink: micronutrient and caffeine composition, antibacterial and antioxidant activities

Abstract

Mousa Tarawneh, Ahmad M. Al-Jaafreh, Hammad Al-Dal'in, Haitham Qaralleh, Moath Alqaraleh, Moayad Khataibeh.

Excessive consumption of coffee and caffeine containing products may increase the likelihood of adverse effects. Therefore, this study designed to evaluate the roasted date and roasted barley beans as an alternative’s coffee beverages. The micronutrient (Fe, Zn and Cu) and caffeine contents were measured atomic absorption spectrophotometer. The antibacterial activity was examined using disc diffusion method and the antioxidant activity was evaluated using ABTS and DPPH assays. The results showed that there were no significant differences between all samples tested regarding the concentrations of Fe, Zn and Cu. Besides, the coffee samples exhibited broad spectrum antibacterial activity (inhibition zone ranged from 8.5 to 11.5mm) while roasted date and barley beans showed narrow spectrum antibacterial activity against gram-positive bacteria (8.5-10.5mm). Using ABTS and DPPH assays, roasted coffee (Saudi Habshi) exhibited the strongest antioxidant activity followed by roasted coffee (Colombian), roasted barley, green coffee (Colombian) and roasted dates. The presence of these elements at comparable concentrations and the remarkable antibacterial and antioxidant activities of date and barley beans supports the hypothesis of using them as a coffee substitute.