Table 3.
(Poly)phenol content of white, yellow, and red sweet potato flesh.
| Sweet Potato Flesh Color (Origin) | Sample Extraction |
Analytical Method | Phytochemical | Amount of Phytochemical | Ref. |
|---|---|---|---|---|---|
| White (USA) | Methanol (80%) | Folin-Ciocalteu | TPC | <0.1 mg CA/g FW | [9] |
| White and orange (Italy) | Methanol | Folin-Ciocalteu | TPC | Raw: 794 mg GA/kg DW | [24] |
| Boiled: 1803 mg GA/kg DW | |||||
| Fried: 2605 mg GA/kg DW | |||||
| Microwaved: 1836 mg GA/kg DW | |||||
| Steamed: 1743 mg GA/kg DW | |||||
| White-fleshed (Korea) |
50% MeOH withn1.2 M HCl at 80 °C | HPLC system | Flavonoids: quercetin, myricetin, kaempferol. | Flavonoids: 45.4 µg/g DW (Quercetin: 19.8, myricetin: 23.4, kaempferol: 2.1) | [27] |
| Phenolic acids: ferulic, p-coumaric, p-hydroxybenzoic, sinapic, syringic, and vanillic acids. | Phenolic acids: 52.5 µg/g DW (p-hydroxybenzoic acid: 5.5, vanillic acid: 7.5, syringic acid: 3.7, p-coumaric: 7.5, ferulic acid: 15.1, sinapic acid: 13.3) | ||||
| Yellow (USA) | Methanol (80%) | Folin-Ciocalteu | TPC | <0.1 mg CA/g FW | [9] |
| Red (Peru) | Methanol | Folin-Ciocalteu | TPC | 945 mg CA/100 g FW 3220 mg CA/100 g DW | [21] |
| 0.225 N HCl in ethanol (95%) | pH-differential | Total monomeric anthocyanins (Cya 3-glc) | 182 mg total anthocyanins/g FW 618 mg total anthocyanins/g DW | ||
| Red | NS | pH-differential | TAC | 2.4 to 40.3 mg total anthocyanins/g FW | [37] |
CA: chlorogenic acid; Cya: cyanidin; DW: dry weight; Fresh weight; GA: gallic acid; Glc: glucoside; HPLC: high-performance liquid chromatography; NS: non-specified; TPC Total phenolic content; TFC: Total flavonoid content; TAC: Total anthocyanin content.