Ultrasonic-Assisted Nanoparticle Engineering to Enhance the Extraction Efficiency and Sensory Quality of Saudi Coffee

Saudi coffee, made from Khawlani beans, is known for its sweeter, less acidic flavor and rich content of bioactive compounds. However, traditional preparation methods are time consuming and inefficient in extracting these compounds, limiting their global appeal. This study introduces an ultrasonic-assisted nanoparticle preparation technique to enhance the extraction efficiency, chemical profile, and sensory quality of Saudi coffee. The method aims to overcome limitations of traditional grinding by reducing the particle size while preserving key bioactive compounds.

Finely ground coffee was subjected to ultrasonic processing at optimized parameters 450 W (60% of 750 W output), with 10 min of pulsed sonication to produce nanoparticles. These were characterized using SEM, FT-IR, XRPD, and particle size analysis. Comparative chemical analysis (caffeine, total phenols) and sensory evaluation were conducted against regular Saudi coffee.

Ultrasonication reduced the particle size to ~101 nm, significantly enhancing caffeine (from 0.54 to 3.21 mg/g) and phenolic content (from 426.7 to 1825.3 µg GAE/g). Solubility also increased from 40.7% to 75.9%. Sensory tests showed an improved aroma, mouthfeel, and flavor. These improvements are attributed to an enhanced extraction and surface area at the nanoscale.

Ultrasonic-assisted nanoparticle technology significantly improves the physicochemical and sensory properties of Saudi coffee. This approach offers a fast, scalable, and eco-friendly method for quality enhancement, positioning Saudi coffee for greater global competitiveness.