Table 1.

Extraction technologies for crude propolis extraction.

No	Extraction Solvent (ES) (Special Conditions)	Extraction Type	P:ES Ratio (w/v)	Extraction Temperature	Extraction Duration	Ref.
1	EtOH (25–60% v/v)/H2O	M	1:5	r.t.	typically 10–30 days	[126]
2	EtOH (10–95% v/v)/H2O	M + P, SE	1:12.5	Δ/70 °C	30 min	[127,128]
3	H2O	E	n.r.	Δ/30–50 °C	6–8 min	[129]
4	H2O	E	1:20	Δ/70–95 °C	18 h	[130]
5	H2O (4× repeated with fresh H2O)	M	1:4	r.t.	72 h	[131]
6	H2O	E	1:2	Δ/60 °C	30 min	[132]
7	H2O	UAE	1:10	Δ/50–60 °C	2.5 h	[133]
8	OS: MeOH, n-PrOH, i-PrOH, n-BuOH, s-BuOH, t-BuOH, Et2O, BnOH, 1,2-PG, DMSO, ETG, BnBz, PEG, acetone, HOAc	M	1:2	r.t.	10 days	[134]
9	1,2-PG	M/E	1:10–1:20	r.t. or Δ/50–60 °C	10 days 2 h	[135]
10	H2O/PEG 400 (20% v/v)	M	1:10	r.t.	5 h	[136]
11	Glycerol (GL)	n.r.	n.r.	n.r.	n.r.	[8]
12	Glycerol (GL)	E	1:2	Δ/90–160 °C	n.r.	[129]
13	Plant oil	n.r.	n.r.	n.r.	n.r.	[8]
14	EtOH (96%)/sunflower oil (60:40 w/w)	n.r.	n.r	n.r	n.r	[137]
15	OPEO (mostly d-limonene)	M	1:9	r.t.	48 h	[138]
16	CC/1,2-PG (1:1, n/n)	E	1:20	Δ/50 °C	3 h	[139,140]
17	CC/1,2-PG (1:2, n/n)	E	1:20	Δ/50 °C	3 h	[139,140]
18	CC/LA/H2O (1:2:2, n/n/n)	E	1:20	Δ/50 °C	3 h	[139,140]
19	CC/LA/H2O (1:1:1, n/n/n)	E	1:20	Δ/50 °C	3 h	[139,140]
20	Lys/H2O (1:10, n/n)	E	1:20	Δ/50 °C	3 h	[139,140]
21	scCO2	scE	1:10	Δ/40–60 °C 10–20 MPa	n.r.	[141]
22	H2O/GL (3:1)/HP-β-CD (22.5%) or H2O/GL (1:1)/HP-β-CD (11.25%)	CAAE	n.r.	n.r.	n.r.	[142]
23	EtOH/H2O, 80:20, v/v (UAE; 120 W; closed vessel)	UAE	1:10	Δ/70 °C	1 h	[20]
24	EtOH/H2O, 80:20, v/v MAE: 300 W/2450 MHz/ closed vessel	MAE	1:10	Δ/106 °C	15 min	[20]
26	EtOH/H2O, 70:30, v/v UAE: 300 W/20 KHz MAE: 800 W/2450 MHz	UAE MAE	1:10 or 1:20	25 °C	UAE: 30 min MAE: 2 × 10 s	[143]
27	EtOH/H2O, 70:30, v/v UAE: 20 KHz MAE: 140 W/2450 MHz	UAE MAE	1:50	UAE: r.t. MAE: ≈60 °C	UAE: 15 min MAE: 2 × 1 min	[144]
28	EtOH/H2O, 75:25, v/v HPE: 500 MPa	HPE	1:35	r.t.	1 min	[147]
29	H2O/EM EM: PS, PECO, LE, MG, PVA, PEO, PAA, cPAA, CMC, GG, XG, cPA	E	typically 1:10	Δ/40–100 °C	2–24 h	[148]
30	PEG200–600/LE (0.1–3.5% w/w)	M/E	1:2–1:20	r.t. or 10–150 °C	5 min to 72 h	[149]
31	1. step: H2O/16.6 kPa/100 V 2. step: EtOH/H2O, 70:30, v/v, 16.6 kPa/220 V	VRHE	n.r.	1. 58 °C 2. 37 °C	2 × 20 min	[150]

P:ES ratio = a ratio between the weight starting crude propolis and volume of employed extraction solvent, expressed as w/v; M = maceration, a batch-type extraction at room temperature (r.t.; typically 20–25 °C); P= percolation; SE = Soxhlet extraction; E = a batch-type extraction at elevated temperatures; UAE = ultrasound-assisted extraction; OS = organic solvent; MeOH = methanol; n-PrOH = 1-propanol; i-PrOH = 2-propanol; n-BuOH = 1-butanol; s-BuOH = 2-butanol; t-BuOH = tert-butanol; Et₂O = diethylether; 1,2-PG = 1,2-propylene glycol; DMSO = dimethylsulfoxide; ETG = ethylene glycol; BnBz = benzyl benzoate; PEG = polyethylene glycol; HOAc = glacial acetic acid; n.r. = not reported; DER = drug-to-extract weight ratio during extraction; Δ = elevated temperature; GL = glycerol; OPEO = orange peel essential oil; CC = choline chloride; NADES = natural deep eutectic solvents; Lys = L-lysine; sc = supercritical; scE = supercritical extraction, usually a batch-type extraction process with scCO₂ as the ES; HP-β-CD = hydroxypropyl-β-cyclodextrin; CAAE = a complexing agent-assisted extraction; MAE = microwave-assisted extraction; EM = emulsifier; PS = polysorbates, PECO = polyoxyethylene castor oil derivatives; LE = lecithin; MG = monoglycerides; PVA = polyvinyl alcohol; PEO = polyethylene oxide; PAA = polyacrylamide; cPAA = cross-linked PAA, CMC = sodium carboxymethyl cellulose; GG = guar gum; XG = xanthan gum; cPA = cross-linked polyacrylate; HPE = high pressure extraction; VRHE = vacuum resistive heating extraction.