Study on infrared-assisted extraction coupled with high performance liquid chromatography (HPLC) for determination of catechin, epicatechin, and procyanidin B2 in grape seeds

In this study, infrared-assisted extraction (IRAE) was developed and combined with HPLC for the determination of catechin, epicatechin, and procyanidin B2 in grape seeds. Three factors, extraction solvent, solid/liquid ratio, and illumination time, were investigated to optimise the extraction method of catechin, epicatechin, and procyanidin B2 from grape seeds. The chosen infrared-assisted extraction conditions were as follows: a 50% methanol solution as extraction solvent, solid/liquid ratio of 1:150 g/mL and illumination time of 30 min. The extraction efficiency of IRAE was compared with conventional microwave-assisted extraction (MAE), ultrasonic extraction (UE), and classical electrical heating (CEH) methods. An initial HPLC method was established to identify and quantitate catechin, epicatechin, and procyanidin B2 from grape seeds, simultaneously. The HPLC method was validated for parameters including linearity, analytic limit, reproducibility, accuracy and recovery. The results indicted that IRAE has a great potential for offering an alternative technique for extraction of active components from plants.

Research highlights
► The IRAE was a new extraction method.
► Catechin, epicatechin, procyanidin B2 determined in one chromatographic condition.
► The IRAE indicated its own merit comparing with traditional extraction methods.