Table 4.

Main features, advantages, and limitations of emerging extraction technologies.

Emerging Technologies	Main Features	Advantages	Limitations	References
HPH	Using high pressure intensifiers to expose biomass to high-levels of mechanical stress and shear results in complete deformation and disruption of the plant cell structure and improves the release of intracellular bioactive compounds from agri-food by-products	Short extraction time No solvent or a small amount of solvent is required Environmentally friendly method Improved extraction yield	Non-selective method High costs and capital investments Operators training is required	[15,99,100]
PEF	Exposing plant matrices to a moderate electric field and relatively low energy input induces the electropermeabilization of cell membranes by pore formation	Selective extraction of compounds Energy efficient and low-cost operation Short processing time Non-thermal, and non-destructive technology Continuous operability Easy scalability at industrial level	High costs and capital investments Operator training is required Reduced uniformity of PEF treatment due to the presence of air bubbles Uneven distribution of the electric field in the treatment chamber that can be corrected by geometry, insulator design, or inserting metal mesh Arching phenomenon and undesirable electrochemical reactions due to high electric field intensity	[101,102,103]
US	Acoustic cavitation followed by the release of a huge amount of energy creating shear stresses, allowing greater penetration of the solvent into the plant tissue	Low energy requirement Short extraction time Less solvent requirement Improved extraction efficiency	Non-selective method Damages to heat labile compounds Decreased intensity of equipment due to aging, lessening the reproducibility	[22,91,92]
SFE-CO2	Supercritical fluids allow for increased solvating power of gases beyond their critical point to extract compounds from the biomass	Low temperature operation Recovery of thermosensitive compounds Selectivity increases with changing pressure and temperature Recovery of extracted compounds with little or no solvent residues by depressurization Easy scalability of the process at the pilot and industrial level Reuse supercritical carbon dioxide Use of environmentally friendly solvents	High capital investments Complexity of the system Operators training is required Poor selectivity for polar compounds due to the low polarity of supercritical carbon dioxide	[93,94,104]
MW	Microwave heating causes physical and biological modifications of the biomass, improving the penetration of the extracting solvent into the vegetable tissue	Short extraction time High extraction yield Energy efficient process Low capital investments Low environmental pollution	Non-selective method Not uniform heating, reducing extraction efficiency Thermal degradation of phenolic compounds due to overheating of biomass Limited penetration of microwaves for scaling up Changes induced on the chemical structure of the target compounds, hindering their bioactivity and reducing their potential applications Limitation for the recovery of nonpolar compounds	[82,98,105,106]