A Sustainable Extraction Approach of Phytochemicals from Date (Phoenix dactylifera L.) Fruit Cultivars Using Ultrasound-Assisted Deep Eutectic Solvent: A Comprehensive Study on Bioactivity and Phenolic Variability

What if the secret to greener chemistry lies hidden in a date fruit? Scientists have found a way to replace harsh chemical solvents with a natural, sugar-based mixture—and the results are surprisingly sweet.

Dates are more than a sweet treat—they're a treasure trove of bioactive compounds. In a new study, researchers turned to eight Algerian date cultivars, using natural deep eutectic solvents (NADESs) made from lactic acid and sucrose to extract phytochemicals. This eco-friendly approach, powered by ultrasound, offers a sustainable alternative to conventional chemical solvents. The extracts were then tested for their phenolic content, antioxidant power, and enzyme inhibition.

The results revealed remarkable diversity among cultivars. The Ourous cultivar stood out, boasting the highest levels of total phenolics (1288.7 mg GAE/100 g), flavonoids (53.8 mg QE/100 g), proanthocyanidins (179.5 mg CE/g), and triterpenoids (12.88 mg OAE/100 g). It also led in antioxidant activity, showing strong scavenging against DPPH and ABTS radicals, plus impressive ferric-reducing power. All extracts showed moderate antioxidant effects in other assays, and inhibited enzymes like α-amylase and acetylcholinesterase—Ourous again leading with 45% and 37% inhibition, respectively.

Using HPLC-DAD-MS, the team identified five phenolic compounds, with gallic acid dominating in the Tazizaout cultivar, which showed the highest phenolic variability. This study confirms that combining ultrasound with NADESs is not only effective but also environmentally friendly, making it a promising tool for the food and pharmaceutical industries.

Key Points

• NADES with ultrasound beats chemical solvents for green extraction.
• Ourous cultivar tops phenolics, flavonoids, and antioxidant activity.
• Five phenolics found; gallic acid dominates in Tazizaout.