Table1 Process parameters, advantages, and disadvantages of different extraction techniques
From: Review on the extraction of bioactive compounds and characterization of fruit industry by-products
Parameters involved | Advantages | Disadvantages | References |
|---|---|---|---|
Conventional solvent extraction | |||
Plant materials (moisture content, particle size, pH) Solvent parameters (solid: solvent ratio, choice of the solvent, boiling point of the solvent, mixing the composition of solvents) Process parameters (temperature, pressure) | Low cost Simple operation Suitable for thermolabile compounds Ease extraction of flavonoids Enviro-friendly because of solvent usage as water | A tremendous amount of solvent is required Higher extraction time and energy Low extraction efficiency Higher toxicity Polar solvents are commonly used Degradation of extracts Several additional steps required for extraction Solvent presence in extracts | (Ares et al. 2018; Gu et al. 2019; Mehmood et al. 2019; Taofiq et al. 2019) |
Enzyme-assisted extraction | |||
Plant materials (moisture content, nutrient availability, particle size) Enzyme parameters (type, concentration, composition, characteristic properties, mixing ratio) Solvent (types of solvent, solvent ionic strength) Process parameters (temperature, pH, process time) | High recovery of phytochemicals Low energy and time consumption No requirement of additional steps Low residual levels Not altering the structure of the cell Limited equipment corrosion No toxic waste Low Temperature and Cost | Cost of enzymes is relatively higher Can't completely hydrolyze the structure of the cell wall Scale-up process High disbursement for the drying after the enzyme treatment Very long extraction time of 1–4 h Filtration must be required | (Adetunji et al. 2017; Gong et al. 2020; Grassino et al. 2020; Nadar et al. 2018; Panja 2018) |
Supercitical Fluid extraction | |||
Plant materials (particle size, moisture content, surface area, porosity) Solvent parameters (density, diffusivity, viscosity, polarity, compressibility, solvent mixture ratio, flow rate, vapour pressure) Process parameters (temperature, pressure, dynamic time) | CO2 is chemically inert, non-toxic, cheap, well-accepted food-grade solvent Low polarity, high diffusivity solvent Allowing low polar molecules with additional clean set-up Inactivation of microorganisms Low cost, low consumption of chemicals Clean and free solvent extract Reduce the oxidation of component Can penetrate faster than the other solvent | It is a non-polar solvent so that it can't extract polar extracts Requires modifiers Complex equipment Barely applied for extraction and fractionization of carbonyl The presence of water may cause problems Risk of volatile compounds High capital investment and cost Elevated pressure is required Many parameters to optimize | (Al-Otoom et al. 2014; Gere et al. 1997; Pinto et al. 2020; Pourmortazavi and Hajimirsadeghi 2007) |
Subcritical fluid extraction | |||
Plant materials (particle size, moisture content) Solvent parameters (temperature, critical pressure, mixing, flow rate, modifiers, additives) Process parameters (modes, time of extraction, Solid: liquid ratio) | Shorter extraction time Higher efficiency The continuous process is possible Less expensive instrument Polar, moderately polar solvent Low polar and non-polar compounds can be extracted separately Water is an extraction solvent that has the benefits of being green, cheap, and readily available | Equipment is not easy to clean More reactive and corrosive Thermal degradation may occur at high temperature Improper control process condition Hydrolysis of the pectin chain Not easy to remove moisture from the extracts and may require additional procedures, including evaporation, dehydration, precipitation | (Essien et al. 2020; Gallego et al. 2019; Zhang et al. 2020) |
Microwave-assisted extraction | |||
Plant materials (moisture content, particle size, texture complexity, dielectric loss factor) Solvent parameters (pH, volume, dielectric properties, solid: solvent ratio, density) Process parameters (microwave power, temperature, pressure, time of extraction) | Heating is homogenous No temperature gradient between solid and solvent system Minimized solvent use Lower time of extraction and cost Improved extraction yield Simple in operation Minimum labour used No risk of oxidation Volumetric heating Volatile compounds can be removed without any loss | Solvents solution may cause wear in types of equipment Not suitable for thermosensitive compounds Sometimes fat oxidation occurs To collect the volatile compound, the vessel is to be cooled Solution temperature is low | (Al-Dhabi and Ponmurugan 2020; Arrutia et al. 2020; Okolie et al. 2019; Upadhyay et al. 2012) |
Ultrasound-assisted extraction | |||
Plant materials (emulsifying capacity, solubility texture, liquid: solid ratio, presence of dissolved gases) Solvent parameters (type of solvent, mixture ratio, reaction of solvent towards the target compounds) Process parameters (frequency range, frequency combination, vibration of the probe, amplitude displacement, ultrasonic generator, ultrasound intensity, shape and size of the ultrasonic reactor, pressure, temperature, pump flow) | Improve the efficiency Reduce time of extraction and cost Increase the extraction yield Reduce the amount of solvent Versatile in terms of solvents Rapid and reproducible Prevention of material and solvent wastage Lower process temperature No costly equipment Lower environment polluting risks Less expensive than microwave digester Replaceable with GRAS solvents Used for thermolabile compounds | The repetition of the process would be done Non-uniformity of ultrasound with solution Harmful for human health by toxic solvent More solvent will be required Filtration is needed The target compounds are sometimes overcooked Generation of oxidizing species (OH+, H2O2) for the oxidation of organic material | (Belwal et al. 2020; Carrillo-Hormaza et al. 2020; Chakraborty et al. 2020; Dzah et al. 2020; Meregalli et al. 2020; Saifullah et al. 2020) |
Pulsed electric field assisted extraction | |||
Plant materials (the moisture content of biomass, Size, and shape of the plant cell) Solvent parameters (solvent type, solvent: sample ratio) Process Parameters (flow rate, frequency, extraction time, temperature, the diameter of the chamber, numbers, and duration of electric pulses) | Cheaper and usage of less energy Non-toxic Environment-friendly solvents usage Moderate temperature Improving productivity Higher selectivity for intracellular products Increase the extraction rate Decrease the amount of solvent Shortening the extraction time Avoiding quality loss and fractionization of non-pure extracts | The high cost of equipment A high voltage pulse is required Insulation should be there Electrode usage causes corrosion Dependence of medium Composition or conductivity of solvent | (Andreou et al. 2020; El Kantar et al. 2018a; Medina-Meza and Barbosa-Cánovas 2015; Plazzotta et al. 2021) |