2.1. Materials
The extraction solvents ethanol (99.5%, ACS reagent), dichloromethane (99.5%, ACS reagent), and ionic liquids (ILs) (IL1: 1-n-Hexyl-3-methylimidazolium chloride, 98% and IL2: 1-Ethyl-3-methylimidazolium chloride, 97%) were purchased from Fisher Scientific (Fisher Scientific, Waltham, MA, USA). The selection of ionic liquids was based on previous literature for higher affinity for polar lipids and phenolic molecules. The solutions of ILs (40 mL) were prepared by mixing two ionic liquids with ethanol (99%) as co-solvent at 1:2 (w/v) ratio. The waxy burgundy whole grain sorghum was kindly donated by Nu Life Market LLC (Nu Life Market LLC, Scott City, KS, USA).