A Modified Method for the Determination of Acylated Anthocyanins in Purple-fleshed Sweet Potato (Ipomoea batatas (L).) Tubers by High-performance Liquid Chromatography with Visible Absorption

This paper described a modified HPLC method for the determination of eight acylated anthocyanins in purple-fleshed sweet potato tuber samples, including lyophilized powder and concentrated juice. Recoveries determined for two materials spiked with anthocyanin levels of 71 µg g−1 to 8.8 mg g−1 ranges 91.8–105.0%. For repeatability, the relative standard deviation and intermediate precision ranged from 0.8% to 5.0% and 1.9% to 8.2%, respectively. HorRat values ranged from 0.3 to 1.0, except for YGM-1a and YGM-1b in two samples, which were well within the limits of performance acceptability. The proposed method showed good intralaboratory reproducibility in the range from 0.10 ± 0.0027 (mean ± expanded measurement uncertainty, k = 2) to 0.51 ± 0.016, 0.10 ± 0.0084 to 0.21 ± 0.011, 0.40 ± 0.017 to 4.5 ± 0.12, 0.21 ± 0.0066 to 0.96 ± 0.021, 0.23 ± 0.014 to 0.57 ± 0.026, 0.15 ± 0.0087 to 1.3 ± 0.040, 0.94 ± 0.021 to 6.5 ± 0.19, and 0.63 ± 0.016 to 2.4 ± 0.061 mg g−1 for YGM-1a, YGM-1b, YGM-2, YGM-3, YGM-4b, YGM-5a, YGM-5b, and YGM-6, respectively.