Appraisal of Phenolic Compounds, Antioxidant Activity and in Vitro Gastrointestinal Digestion of Borage (echium Amoenum) Flowers Using Natural Deep Eutectic Solvent (NADES)

Borage is used traditionally in folk medicine for centuries and is reputed in many ancient civilizations. This paper examined the effectiveness of natural deep eutectic solvent (NADES) based on choline chloride and glycerol (CHGLY) for the extraction of phenolic compounds from borage. The results showed that NADES was significantly more efficient than the traditional solvents such as water, methanol and ethanol. NADES gave the highest amounts of gallic acid (157.25 ± 8.47 mg/kg), catechin (100.21 ± 014 mg/kg), hydroxybenzoic acid (256.00 ± 1.70 mg/kg), chlorogenic acid (530.91 ± 15.85 mg/kg), caffeic acid (95.70 ± 9.26 mg/kg), vanillic acid (600.07 ± 6.19 mg/kg), epicatechin (175.99 ± 10.35 mg/kg), ρ-coumaric acid (77.17 ± 5.16 mg/kg) and ferulic acid (33.13 ± 096 mg/kg). These phenolic compounds were optimized by choosing the molar ratio, water content, extraction temperature and extraction time as variables. The optimum conditions were 1:3.40 of molar ratio, 40