Pressurized liquid extraction and quantification of anthocyanins in purple-fleshed sweet potato genotypes

► Anthocyanins in purple-fleshed sweetpotatoes extracted by pressurized-liquid extraction. ► Optimum conditions 80-100 °C and acetic acid:methanol:water solvent of 7:75:18% (v/v). ► Anthocyanin content varied widely among genotypes, up to 210 mg/100 g fresh weight. ► High correlation in pH-differential anthocyanin determination and Japan color values.