Table 1.

(Poly)phenol content of orange sweet potato flesh.

Origin	Sample Extraction	Analytical Method	Phytochemical	Amount of Phytochemical	Ref.
USA	Methanol (80%)	Folin–Ciocalteu	TPC	~1.4 mg CA/g FW	[9]
	Methanol (80%)	pH-differential	TAC	<0.1 mg anthocyanins/g FW
USA	Ethanol (80%)	Folin–Ciocalteu	TPC	~0.1 mg CA/g FW	[20]
Bangladesh	Acetone:water (7:3, v/v)	Folin-Ciocalteu	TPC	94.3 to 136.1 mg GA/100 g FW	[13]
Kenya	Methanol (80%)	Folin–Ciocalteu	TPC	TPC mg GA/100 g DW: -Raw: 4025.4 to 4999.4 -Boiling: 1222.8 to 4699.7 -Dehydration: 659.3 to 5861.7 -Fermentation and dehydration: 1662.4 to 3962.3	[18,25]
		Aluminum chloride	TPC	TPC mg catechin/100 g DW: -Raw: 1294.3 to 4211.2 -Boiling: 998.2 to 1554.4, -Dehydration: 411.0 to 3816.2 -Fermentation and dehydration: 913.8 to 3270.7
USA	Ethanol (80%)	Folin–Ciocalteu	TPC	57.1 to 78.6 mg CA/100 g FW	[20]
		HPLC-DAD and LC-MS/MS	Phenolic acids: chlorogenic acid, caffeic acid, di-O-caffeoylquinic acids	Phenolic acids mg/100 g FW: -Chlorogenic acid 5.1 to 9.3 -Caffeic acid 5.1 to 9.3 -4,5-di-O-caffeoylquinic acid 0.6 to 2.4 -3,5-di-O-caffeoylquinic acid 2.3 to 6.5 -3,4-di-O-caffeoylquinic acid 0.2 to 0.5
Pakistan	Ethyl acetate	Folin–Ciocalteu	TPC	319.8 μg GA/mg DE	[26]
	Methanol			262.6 μg GA/mg DE
	Ethyl acetate	Aluminum chloride	TFC	208.8 μg quercetin/mg DE
	Methanol			177.8 μg quercetin/mg DE
Korea	Methanol (50%) withn1.2 M HCl at 80 °C	HPLC system	Quercetin, myricetin, kaempferol, luteolin, ferulic, p-coumaric, p-hydroxybenzoic, sinapic, syringic, and vanillic acids.	Flavonoids: 127.1 µg/g DW (Quercetin: 59.9, myricetin: 39.8, kaempferol: 18.9, luteolin: 8.5) Phenolic acids: 71.1 µg/g DW (p-hydroxybenzoic acid:7.8, vanillic acid 7.9, syringic acid:3.8, p-coumaric:11.9, ferulic acid:24.6, sinapic acid:15.2)	[27]

CA: chlorogenic acid; DE: dry extract; DW: dry weight; FW: Fresh weight; GA: gallic acid, HPLC: high-performance liquid chromatography; MS: mass spectrometry; TPC: Total phenolic content; TFC: Total flavonoid content; TAC: Total anthocyanin content.