Deep eutectic solvents (DESs) and natural deep eutectic solvents (NADESs): Designer solvents for green extraction of anthocyanin

Anthocyanins are extracted using organic solvents for their chemical or biological applications. Recently, alternative solvents namely, ionic liquids (IL), deep eutectic solvents (DESs), and natural deep eutectic solvents (NADESs) are being used for the extraction of anthocyanins with remarkable efficiency. These potential solvents are less hazardous and environmentally friendly compared to conventional extraction solvents. This review is the first attempt to exclusively discuss the application of DES and NADES for anthocyanin extraction from different food materials and their by-products. Acid-based DES and 20–30% water resulted in the highest anthocyanin extraction yield from samples compared to sugars and polyol-based DES. Ultrasonic-assisted extraction was the most common and efficient method for anthocyanin extraction. DES-based extracts also presented the highest stability and antioxidant activity. Fruits and their by-products are the most commonly used samples whereas cereal and legumes are the least explored.