Environmentally Friendly Methods for Flavonoid Extraction from Plant Material: Impact of Their Operating Conditions on Yield and Antioxidant Properties

Table 2

Conditions of the extraction of flavonoids by ultrasound.

Source	Experimental conditions	Flavonoid	Yield	Reference
T. inflorescentia	Solv: 80% MeOH; Temp: 60°C; Time: 20 min; Frequency: —; Power: —; Liquid-solid ratio: 25 mL/g	Rutin; Isoquercetrin; Astragalin; Tiliroside	565.49 ± 12.69 μg/g; 118.47 ± 5.64 μg/g; 63.55 ± 1.10 μg/g; 910.28 ± 26.82 μg/g	[92]
Calligonum comosum	Solv: MeOH, EtOH; Temp: 30°C; Time: 30 min; Frequency: —; Power: 720 W; Liquid-solid ratio: 10 mL/g	TFC	0.51 ± 0.14 mg/g (MeOH); 32.97 ± 0.78 mg/g (EtOH)	[93]
Mandarin peel	Solv: 80% Ac; Temp: 48°C; Time: 40 min; Frequency: —; Power: 56.71 W; Liquid-solid ratio: 20 mL/g	Hesperidin	6435.53 mg/100 g	[63]
Arbutus unedo L. fruits	Solv: 58.8% EtOH; Temp: —; Time: 28.6 min; Frequency: —; Power: 246.7 W; Liquid-solid ratio: 20 mL/g	TFC	29.49 ± 0.72 mg/g	[65]
Selaginella helvetica	Solv: 95% EtOH; Temp: 47°C; Time: 40 min; Frequency: —; Power: 250 W; Liquid-solid ratio: 12.7 mL/g	Biflavonoids	Approx. 12.1 mg/g	[69]
Camellia oleifera seeds	Solv: 60% EtOH; Temp: 30°C; Time: 30 min; Frequency: —; Power: —; Liquid-solid ratio: 50 mL/g	TFC	15.91 ± 0.86 mg/g	[80]
Nectandra grandiflora	Solv: 96% EtOH; Temp: 50°C; Time: 30 min; Frequency: —; Power: 750 W; Liquid-solid ratio: 20 mL/g	TFC	114.50 ± 0.71 mg/g	[81]
Hypericum formosanum tissues	Solv: 73.5% EtOH; Temp: 62.5°C; Time: 38.3 min; Frequency: 40 kHz; Power: —; Liquid-solid ratio: 100 mL/g	TFC	101.7 ± 1.7 mg/g	[94]
Amaranthus paniculatus leaves (a), defatted seeds (b), and non-defatted seeds (c)	Solv: 90 : 10 MeOH: EtOH; Temp: 25°C; Time: 50 min; Frequency: —; Power: —; Liquid-solid ratio: 15 mL/g	Rutin	3.62 ± 0.06 g/kg (a); 0.19 ± 0.001 g/kg (b); 0.34 ± 0.002 g/kg (c)	[95]
Oryza sativa cv. Poireton	Solv: 67.34% EtOH; Temp: 49.46°C; Time: 10.02 min; Frequency:—; Power: —; Liquid-solid ratio: 40.79 mL/g	TFC	3.01 mg/100 g	[96]
Pistacia vera L. hulls	Solv: MeOH/water/FA (80 : 19 : 1); Temp:—; Time:—; Frequency:—; Power:—; Liquid-solid ratio: 60 mL/g	Total flavonols	3.38 ± 0.18 g/kg	[97]

Solv: solvent, Temp: temperature, TFC: total flavonoid content, EtOH: ethanol, MeOH: methanol, Ac: acetone, and FA: formic acid.