Ultrasound-assisted deep eutectic solvent extraction of bioactive compounds from persimmon calyx

Area of Science:

• Green Chemistry
• Food Science
• Natural Product Extraction

Background:

• Persimmon (Diospyros kaki) calyx is a potential source of valuable bioactive compounds.
• Traditional extraction methods often rely on organic solvents, posing environmental concerns.
• Deep eutectic solvents (DES) offer a sustainable and effective alternative for natural product extraction.

Purpose of the Study:

• To investigate ultrasound-assisted extraction (UAE) of bioactive compounds from persimmon calyx using DES.
• To optimize extraction parameters, including DES molar ratios and water content.
• To evaluate the antioxidant activities of the extracted compounds.

Main Methods:

• Ultrasound-assisted extraction (UAE) was employed.
• Deep eutectic solvents (DES) with varying molar ratios of lactic acid and choline chloride were utilized.
• Extraction efficiency was assessed by measuring total phenolic-flavonoid content and antioxidant activities (DPPH•, CUPRAC, FRAP).
• Principal Component Analysis (PCA) was used to determine correlations between parameters.

Main Results:

• Optimal sonication time was determined to be 20 minutes.
• A molar ratio of 1.9:1 (lactic acid:choline chloride) and 70% water content yielded the highest phenolic/flavonoid content and antioxidant activity.
• PCA indicated that high flavonoid, FRAP, and DPPH• levels correlated with higher sonication time and lower water/molar ratios.

Conclusions:

• UAE using DES is an effective and green method for extracting bioactive compounds from persimmon calyx.
• DES can be recommended as an environmentally friendly alternative to organic solvents.
• Persimmon calyx waste can be valorized as a source of bioactive compounds, particularly relevant for the food industry and green technology initiatives.