Determination of Anthocyanins in Cranberry Fruit and Cranberry Fruit Products by High-Performance Liquid Chromatography with Ultraviolet Detection: Single-Laboratory Validation

摘要

A single-laboratory validation study was conducted on an HPLC method for the detection and quantification of cyanidin-3-O-galactoside (C3Ga), cyanidin-3-O-glucoside (C3Gl), cyanidin-3-O-arabinoside (C3Ar), peonidin-3-O-galactoside (P3Ga), and peonidin-3-O-arabinoside (P3Ar) in cranberry fruit (Vaccinium macrocarpon Aiton) raw material and finished products. An extraction procedure using a combination of sonication and shaking with acidified methanol was optimized for all five anthocyanins in freeze-dried cranberry fruit and finished products (commercial extract powder, juice, and juice cocktail). Final extract solutions were analyzed by HPLC using a C18 RP column. Calibration curves for all anthocyanin concentrations had correlation coefficients (r²) of ≥99.8%. The method detection limits for C3Ga, C3Gl, C3Ar, P3Ga, and P3Ar were estimated to be 0.018, 0.016, 0.006, 0.013, and 0.011 μg/mL, respectively. Separation was achieved with a chromatographic run time of 35 min using a binary mobile phase with gradient elution. Quantitative determination performed in triplicate on four test materials on each of 3 days (n = 12) resulted in RSDr from 1.77 to 3.31%. Analytical range, as defined by the calibration curves, was 0.57–36.53 μg/mL for C3Ga, 0.15–9.83 μg/mL for C3Gl, 0.28–17.67 μg/mL for C3Ar, 1.01–64.71 μg/mL for P3Ga, and 0.42–27.14 μg/mL for P3Ar. For solid materials prepared by the described method, this translates to 0.06–3.65 mg/g for C3Ga, 0.02–0.98 mg/g for C3Gl, 0.03–1.77 mg/g for C3Ar, 0.10–6.47 mg/g for P3Ga, and 0.04–2.71 mg/g for P3Ar.