Evaluation of Antioxidant Capacity (ABTS and CUPRAC) and Total Phenolic Content (Folin-Ciocalteu) Assays of Selected Fruit, Vegetables, and Spices

Table 1

Extraction solvents as presented in the references.

Reference	Samples tested	Extraction solvents
2	Green tea	Steeping in boiling water
16	Blueberry, blackberry, raspberry, strawberry	Not given
18	Blueberry	Acidified methanol
19	Blueberry, blackberry, raspberry	Aqueous methanol-acetone extraction followed by evaporation, reextraction in diethyl ether-ethyl acetate, final evaporation, and redissolution in methanol
20	Blueberry, blackberry, raspberry	Multiple extractions using methanol
21	Blueberry, blackberry, raspberry, cherry, strawberry	50 : 50 methanol-water extraction followed by 70 : 30 acetone-water extraction
22	Blueberry, blackberry, strawberry	80% methanol
23	Blueberry	60 : 40 ethanol-water
24	Raspberry, strawberry, plum, tomato	Methanol, n-hexane, varying solvents
25	Plum	Multiple extractions using 90% methanol
26	Plum	Methanolic extraction followed by 80% methanol, evaporation, and redissolution in methanol
29	Pumpkin	Multiple extractions using 80% methanol
30	Pumpkin	Various solvents, solvent combinations, and conditions
32	Tomato	Multiple extractions using 75% methanol in water
33	Tomato, capsicum	Multiple extractions using 75% methanol in water
34	Capsicum	Multiple extractions using various solvents and conditions
35	Papaya seeds	Absolute methanol and 80 : 20 methanol-water
36	Papaya seeds	Subcritical water extraction and conventional soxhlet extraction using water
37	Pomegranate husks	Multiple extractions using 75% aqueous methanol including 0.1% () formic acid
38	Pomegranate husks	Compared many different extractions solvents, their combinations and conditions
39	Papaya seeds	Multiple extractions of 95% ethanolic extract after partitioning with water, ethanol extract with petroleum ether, and ethyl acetate
40	Pomegranate husks	Decoction in boiling water
41	Pomegranate seeds, pomegranate husks	Multiple extractions using 80% methanol in water, evaporated and separate hydrolysis followed by extraction with 100% methanol containing 0.1% formic acid
42	Pomegranate husks	96% ethanol
47	Turmeric powder	Boiling water
48	Turmeric powder, ginger powder	Water and 50% ethanol-water at various conditions
49	Turmeric powder	Methanol, water, and ethanol
50	Turmeric	Expressed juice
51	Turmeric powder	Separate multiple extractions using 80% ethanol, 80% methanol, 80% acetone, and water
52	Turmeric powder	Dimethyl formamide
53	Ginger powder	80% methanol
54	Ginger powder	Separate extractions using 80% ethanol and water followed by solvent removal
56	Ginger powder	Multiple extractions using methanol followed by evaporation and redissolution in methanol
57	Cocoa powder	Separate extractions using water and 70% methanol after removing fat with n-hexane
58	Green tea	98°C boiling water
59	Green tea	Steeping in hot water at different temperatures
60	Green tea	Steeping in boiling water
61	Green tea	Steeping in freshly boiled water
62	Green tea	Multiple extractions using 80% methanol