Rapid determination of reducing sugars in demerara sugar using a sustainable smartphone-based digital colorimetry approach

This study presents a novel, eco-friendly, and rapid method for determining low levels of reducing sugars in Demerara sugar using smartphone-assisted digital image colorimetry with the Benedict reaction (DIC-Benedict). Designed as a practical alternative for regulatory analyses, the method emphasizes simplicity, low cost, and on-site applicability. Optimized reagent volume and image acquisition distance ensured robust performance, with adequate linearity (R 2 > 99.8%) and detection and quantification limits of 0.04% and 0.20% ( w / v ), respectively. Matrix effects were minimized by standard addition calibration, ensuring high accuracy (recoveries: 94.9–104.9%) and precision (RSD < 2.0%). Reducing sugar levels in 20 commercial samples ranged from 0.29 to 0.74%, mainly influenced by processing conditions rather than origin. Green metrics (AGREE: 0.6; BAGI: 72.5) confirmed environmental compatibility. Overall, the DIC-Benedict method demonstrates that digital technologies can integrate with classical reactions to provide cost-effective, portable, and sustainable solutions for food analysis and quality control.