Optimizing ultrasound-assisted deep eutectic solvent extraction of bioactive compounds from Chinese wild rice

Can we pull precious health compounds from wild rice using greener, custom-built solvents? Scientists have just unlocked a remarkably efficient way to do it.

When it comes to harvesting valuable nutrients from plants, traditional organic solvents are getting some serious competition. Researchers recently turned their attention to Chinese wild rice, deploying a clever lineup of seven different choline chloride-based deep eutectic solvents to extract its hidden treasures. Among them, a specific mixture paired with 1,4-butanediol—known as DES-2—stole the show, outperforming the rest in yielding total flavonoids, total phenolics, and powerful free radical scavenging capacities.

To make this green chemistry even more effective, the team dialed in the extraction conditions using a Box–Behnken statistical design. The sweet spot? A 76.6% concentration of DES-2, operating at an extraction temperature of 51.2 degrees Celsius and a solid-liquid ratio of 37.0 milligrams per milliliter.

Put to the test with advanced ultra-performance liquid chromatography-triple quadrupole tandem mass spectrometry, this optimized green procedure successfully captured a rich harvest of 9 phenolic and 3 flavonoid compounds. The work highlights a compelling future: the ability to engineer custom green solvents that surpass traditional organic solvents in extraction power.

Key Points

• Tested 7 choline chloride-based green deep eutectic solvents
• Choline chloride/1,4-butanediol showed the best extraction efficiency
• Extracted 9 phenolic and 3 flavonoid compounds successfully