Rapid and eco-friendly quantification of hesperidin and naringin in mandarin peel, orange peel, and pomelo peel by using grinding-assisted ultrasonic extraction

This study presents a rapid and eco-friendly analytical method for quantifying hesperidin and naringin in mandarin peel, orange peel, and pomelo peel, thereby promoting resource utilization and sustainable practices. The method employed straightforward grinding with diatomite for 2 min, followed by extraction using a mixture of N,N-dimethylformamide and methanol (40:60, v/v) with ultrasonic assistance for 2 min, which facilitates the efficient release of bioactive flavonoids. The analysis was performed using high-performance liquid chromatography with a Agilent InfinityLab Poroshell 120 EC-C₁₈ column at 30 °C, employing a gradient elution of 0.1% formic acid aqueous solution and acetonitrile, achieving separation within 5 min. Detection was carried out at 283 nm. Method validation confirmed that this approach exhibits high specificity, precision, and stability. Compared to traditional methods, this approach reduces total analysis time to 9 min, decreases both solvent and energy consumption, and lowers costs. The method’s Greenness Evaluation Metric for Analytical Methods score of 5.691, outperforming other published approaches. The method was applied to analyze 36 batches of citrus peels (12 batches each of mandarin peel, orange peel, and pomelo peel). Hesperidin content in mandarin peel samples ranged from 3.29% to 7.15%, in orange peel samples from 2.06% to 6.03%, and naringin in pomelo peel from 0.07% to 12.40%, demonstrating high analytical accuracy and strong practicality. In conclusion, the established rapid, simple, efficient, and environmentally friendly analytical method effectively supports quality control of citrus peel materials, promotes resource utilization of citrus processing by-products, enabling their transformation into high-value ingredients for the functional food, nutraceutical, cosmetic, and pharmaceutical industries. It aligns with the concept of the green circular economy, and possesses significant potential for widespread application.