Influence of Natural Deep Eutectic Solvent Compositions on the Polyphenol Profile of Citrus aurantium By-Products from Yucatán, México

Citrus waste in Yucatán isn't just trash—it's a treasure chest of health-boosting compounds, waiting for the right green key to unlock it.

In Yucatán, the sour orange (Citrus aurantium) is more than a fruit—it's a cultural icon, squeezed for juice and essential oils. But what happens to the peels and pulp left behind? Tons of by-products pile up, yet they hide a wealth of bioactive molecules. Now, green chemistry is stepping in to turn this waste into wellness, using natural deep eutectic solvents (NADESs)—cheap, easy-to-make, and remarkably efficient at pulling out valuable compounds.

Researchers tested different NADES recipes, varying the hydrogen bond donor (fructose, glucose, or glycerol), the molar ratio with choline chloride (1:1 or 1:2), and the water content (50% or 70%). They measured polyphenols, flavonoids, vitamin C, and antioxidant power in the extracts. The results were striking: glycerol-based solvents proved champions for flavonoids, especially hesperidin, hitting 2186.08 mg per 100 g dry mass at 70% water. Meanwhile, fructose-based solvents excelled at total phenolics and vitamin C, with antioxidant inhibition reaching 84.31%.

This isn't just lab data—it's a roadmap for turning citrus waste into functional ingredients. By fine-tuning solvent composition, we can selectively extract specific bioactives, making the process both greener and more effective. For Yucatán's industry, this means less waste and more value, all thanks to a little chemistry magic.

Key Points

• Glycerol-based NADES maximized hesperidin and flavonoid extraction.
• Fructose-based NADES yielded highest phenolics, vitamin C, and antioxidant activity.
• Hydrogen bond donor type was the most critical factor.