(P36-18-26) Phytochemical Profile, Antioxidant Activity, and Sensory Acceptability of Roasted Date Palm Kernel Tea: A Sustainable Caffeine-Free Beverage

Objectives: Date palm seeds are underutilized by-product with potential for functional beverage development. Despite their bioactive potential, date palm seeds from fruit processing remain underutilized. This study assessed the phytochemical composition, antioxidant activity, physicochemical properties, and sensory acceptability of roasted date palm kernel tea as a sustainable caffeine-free beverage alternative.

Methods: Date palm kernels were washed, dried, and roasted at 160°C, 180°C, and 200°C for 15 min, with unroasted kernels serving as control. Roasted kernels were milled and brewed with boiling distilled water (1:50 w/v) to produce tea infusions. Phytochemical contents (total phenolics, flavonoids, tannins, and phytate) and antioxidant activity (DPPH radical scavenging activity and ferric reducing antioxidant power [FRAP]) were determined using standard methods. Physicochemical properties including moisture content, bulk density, and pH were measured. Sensory evaluation was conducted using a 9-point hedonic scale with 20 semi-trained panelists. Data were analyzed using analysis of variance with significance set at p< 0.05.

Results: Roasting significantly enhanced phytochemical and antioxidant properties of the tea. Total phenolic content increased from 17.16 to 25.13 mg/g, flavonoids from 7.67 to 20.12 mg/g, and tannins from 13.04 to 22.51 mg/g with increasing roasting temperature. Antioxidant activity improved with roasting, with DPPH values increasing from 94.77% to 98.12% and FRAP values from 83.81 to 94.57 mg/100 g. Moisture content decreased from 7.39% to 4.00% and pH decreased from 7.45 to 6.55 with increasing roasting temperature. Sensory evaluation showed tea produced at 200°C had the highest scores for appearance, aroma, taste, and overall acceptability (7.05 on a 9-point scale).

Conclusions: Roasted date palm kernel tea showed enhanced phytochemical composition, antioxidant capacity, and favorable sensory characteristics, particularly at the temperature of 200°C. These findings highlight the potential of date palm kernels as a sustainable raw material for developing caffeine-free functional beverages.

Funding Sources: This study did not receive any external funding.