Ultrasound-assisted extraction of highly nutritious date sugar from date palm (Phoenix dactylifera) fruit powder: Parametric optimization and kinetic modeling

Abstract

Alternative sweeteners to white sugar with a lower calorie content and glycemic index obtained through date palm fruits is of great interest to the food industry. In this study, ultrasound-assisted extraction of nutritive sugar from date fruit powder was investigated through Box-Behnken design. A maximum total sugar content (TSC) of 812 mg glucose eq./g of DFP was obtained with a sugar extraction yield (SEY) of 81.40 ± 0.27 % under the following optimal extraction conditions: extraction temperature of 60 °C, extraction time of 30 min, and L/S ratio of 7.6 mL/g. Various modern techniques were used to characterize the obtained extracts and associated residues. The results showed that the extract contained fructose, glucose, and sucrose and had good thermal stability. Furthermore, SEM and TSC analysis revealed that ultrasonic treatment of the biomass improved mass transfer diffusion due to acoustic or ultrasonic cavitation, resulting in a higher sugar yield.

Keywords

• Ultrasonic extraction
• Date fruit
• Date sugar
• Optimization
• Characterization
• Kinetic modeling