Extraction Methods of Major Phytochemicals: Comparison
View Latest Version
Please note this is a comparison between Version 2 by Peter Tang and Version 3 by Peter Tang.

Scientific studies have established a relationship between the consumption of phytochemicals such as carotenoids, polyphenols, isoprenoids, phytosterols, saponins, dietary fibers, polysaccharides, etc., with health benefits such as prevention of diabetes, obesity, cancer, cardiovascular diseases, etc. This has led to the popularization of phytochemicals. FNowadays, foods containing phytochemicals as a constituent (functional foods) and the concentrated form of phytochemicals (nutraceuticals) are used as a preventive measure or cure for many diseases. The health benefits of these phytochemicals depend on their purity and structural stability. The yield, purity, and structural stability of extracted phytochemicals depend on the matrix in which the phytochemical is present, the method of extraction, the solvent used, the temperature, and the time of extraction.

  • phytochemicals
  • bioactive compounds
  • extraction methods
  • solvents
  • Functional foods

1. Introduction

Phytochemicals are plant-based bioactive compounds produced by plants for their protection. They can be derived from various sources such as whole grains, fruits, vegetables, nuts, and herbs, and more than a thousand phytochemicals have been discovered to date. Some of the significant phytochemicals are carotenoids, polyphenols, isoprenoids, phytosterols, saponins, dietary fibers, and certain polysaccharides. These phytochemicals possess strong antioxidant activities and exhibit antimicrobial, antidiarrheal, anthelmintic, antiallergic, antispasmodic, and antiviral activities [1][2]. They also help to regulate gene transcription, enhance gap junction communication, improve immunity, and provide protection against lung and prostate cancers [3][4][5][6][7]. The recent focus on translational research has enhanced the dimensions of functional foods. Phytochemicals, after extraction from various sources, find profound application in the development of functional foods and nutraceuticals. Phytochemicals exhibit variations in their affinity for solvents and tolerance to heat. The selection of the solvent also affects the quality of the recovered phytochemical and its application in the development of food and nutraceutical products. The solvents can be divided into green solvents [water, ethanol, glycerol, fatty acids/oils, acetic acid, ionic liquids, carbon dioxide (CO2), deep eutectic solvents and natural deep eutectic solvents (NADES), etc.] and other solvents such as acetone, chloroform, butanol, methanol, ethyl acetate, methyl acetate, benzene, hexane, cyclohexane, etc. [8]. Loss in functional properties can occur with the use of non-compatible solvents and varied exposure to different temperatures. Additionally, extraction efficiency depends upon the matrix in which the phytochemical is present. Several matrix-related characteristics, such as matrix type, structure, pre-treatment, particle size, and solid–liquid ratios influence the extraction efficiencies of phytochemicals and extraction techniques [9]. To ensure quality products, phytochemicals must be extracted from the source crop in a manner that retains their natural structure and properties. Hence, it is imperative to select a suitable method of phytochemical extraction. Some of the widely used conventional methods are maceration, percolation, decoction, reflux extraction, and Soxhlet extraction, and the novel methods are pressurized liquid extraction (PLE), high hydrostatic pressure extraction (HHP), microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE), pulsed electric field extraction (PEF), vibro-cavitation extraction, extraction under vacuum-oscillating boiling conditions, extractions in mills, extraction in rotary-pulsation apparatus (RPE), liquid gas extraction (LGS), enzyme-assisted extraction (EAE), supercritical fluid extraction (SFE), and natural deep eutectic solvent extraction (NADES) [8][10].

2. Overview of Major Phytochemicals and Related Health Benefits

The type and concentration of phytochemicals in the source crop vary according to intrinsic and extrinsic factors such as crop type, variety, soil, and environment (region, altitude, and season) of cultivation. This section discusses major phytochemicals, their characteristics, and associated health benefits. A detailed list of major phytochemicals, their sources, and their health benefits is also provided in Table 1.
Table 1. Major phytochemicals, their sources, active sites, and the related health benefits.

Phytochemical

Sources

Active Site

Health Benefits

References

Carotenoids

α-carotene

Mango, pear, peach, pumpkin, butternut squash, green bean, okra, avocado, chard, collard greens, tangerine, banana

Pulp of mango, tangerine, avocado, butternut squash, and pumpkin;

the green part of okra, chard, collard greens

Regulates gene transcription, protects against lung and prostate cancer, good for eye health

[

41

]

White potato, rice, oats, corn

Starchy endosperm of rice, white potato, oats, and corn

Improves intestinal health and increases gut microbiota

[

60

]

[

61

]

Resistant starch

Buckwheat, oats, lentils, peas, beans

Starchy endosperm of oats, buckwheat, and lentils

Cures hypercholesterolemia and obesity; improves gut microbiota

[62]

Arabinoxylan

Rice, barley, guar gum, wheat, finger millet

Starchy endosperm of rice, barley, wheat, and finger millet

Improves gastrointestinal health; reduces diabetics, cancer, and obesity

[63][64][65]

3. Phytochemical Extraction Methods

Extraction is defined as a process of removing or obtaining the desired compounds from the source material [66]. The solvents used for the extraction of phytochemicals can be divided into green solvents such as water, ethanol, glycerol, fatty oils, ionic liquids, acetic acid, isopropanol, supercritical CO2, deep eutectic solvents, natural deep eutectic solvents, etc., and other organic solvents such as acetone, chloroform, butanol, methanol, ethyl acetate, methyl acetate, benzene, hexane, cyclohexane, etc. The green solvents are termed so due to their nontoxic, biodegradable, recyclable, and renewable nature. These solvents also have a high flash point. Among the green solvents, water is the most used and universal solvent. It is a non-selective solvent and can separate all the hydrophilic substances such as saponins, phenolics, polysaccharides, etc. The extraction efficiency of water can be enhanced by superheating, as superheating decreases the dielectric constant of water and provides better penetration. Superheated water is also a better solvent for the extraction of lipophilic substances such as essential oils, as the polarity of water decreases significantly between 100–374 °C. Ethanol is selective in action and is used for the extraction of polyphenols and triterpenes. The extraction efficiencies of ethanol can be modified by using water and acid. Glycerol has high thermal stability (boiling point 290 °C). It is too viscous at low temperatures and hence has a low solubility. It can be used as an extraction solvent above 60 °C or with other co-solvents. Glycerol is not a good solvent for hydrophobic compounds such as fatty acids and oils but is a selective solvent for polyphenolic extraction. Fatty oils are a good solvent for the extraction of hydrophobic substances and can be used for the extraction of carotenoids, coumarins, tocopherols, flavonoids, etc. The major oils used for extraction are soybean, almond, olive, sunflower, etc. Acetic acid buffer can be used for the extraction of phenolics and anthocyanins. Isopropanol is a green alternative to n-hexane. It can be used for the extraction of oils, alkaloids, gums, and natural resins. Supercritical CO2 is used for the extraction of lignans, anthocyanins, and essential oils. Ionic liquids are non-volatile, non-inflammable salts with low melting points (below 100 °C). The melted salts form a liquid that is composed of ions that have high thermal stability, high conductivity, high heat capacity, low flammability, and low or negligible vapor pressure. These can be used for the extraction of a wide range of organic and inorganic compounds such as flavonoids, alkaloids, saponins, lignans, etc. Deep eutectic solvents are a mixture of two or more pure compounds having a eutectic point temperature below an ideal liquid mixture. Deep eutectic solvents are used for the extraction of alkaloids, flavonoids, saponins, and phenolic compounds, and the most commonly used deep eutectic solvents for the extraction of phytochemicals are type III (choline chloride and urea in ratio 1:2) and type IV (choline chloride and zinc chloride in ratio 1:2). NADES solvents are made up of natural metabolites such as organic acids, amino acids, sugars, polyols, and choline derivatives. These solvents have a low volatility and melting point and a broad polarity range. These solvents can be used for the extraction of compounds that are poorly soluble in water. Among the organic solvents, acetone has low toxic potential and is a suitable solvent for the extraction of alkaloids, oils, etc. Ethyl acetate is non-toxic and is used for the extraction of flavonoids, total phenolics, etc. Methanol and chloroform have inherent toxicity. Methanol is used for the extraction of flavonoids, saponins, tannins, etc. Chloroform is used with other solvents such as ethanol and fatty acids for the extraction of alkaloids and anthocyanins. Butanol can be used for the extraction of saponins, total phenolics, and flavonoids; however, it is mainly used for the purification of fractions of individual compounds. n-hexane is a solvent with low acute toxicity. It can be used for the extraction of flavonoids, carbohydrates, anthra-glycosides, and saponins. Methyl acetate is a volatile solvent that is produced by acetic acid esterification with methanol or as a byproduct during methanol carboxylation. It is used mainly for the extraction of phytosterols and tocopherols. Benzene is a potentially dangerous chemical. It can be used for the extraction of flavonoids, phytosterols, alkaloids, and volatile oils. Cyclohexanes are used for the extraction of fats, waxes, and oils [10][67][68][69]. The detailed considerations for the suitable solvent for the extraction of phytochemicals have been discussed by Kim and Wijesekra [70].
The extraction efficiency can be further enhanced by optimizing extraction conditions such as the choice of solvent, temperature, and time. The extraction process starts with cell lysis, followed by the collection of extract, isolation, purification using chromatographic techniques to separate bioactive compounds from the mixture, and identification of phytochemicals using spectrophotometry [71][72][73][74]. Various extraction methods and their mechanism of action are discussed in detail in this section and are also provided in Table 2.
Table 2. The optimized conditions for the extraction of phytochemicals using various extraction methods.

Extraction Method

Solvent

Temperature

Pressure

Time Consumed

References

Maceration

Water, aqueous and non-aqueous solvent

Room temperature or cold method (4–15 °C)

Atmospheric pressure

3–7 days or up to months

[74][75][76]

Percolation

Water, aqueous and non-aqueous solvent

Room temperature or under heat (35–70 °C)

Atmospheric pressure

[7][11][12]

2–24 h

[

77][78]

β-carotene

Decoction

Red pepper, carrot, spinach, peaches, brussel sprout, grapefruit, sour cherries, papaya, mango, romaine lettuce

Water

Green parts of plants, flowers, roots, and stems of plants;

pulp of mango, grapefruit, papaya, etc.

Enhancement of gap junction communication, enhances immunity

Atmospheric pressure

[

1–2 h

6][13][14]

65–70 °C

[

79][80]

Lutein

Asparagus, spinach, kale, green beans, orange pepper, lettuce, broccoli, parsley, pistachio nuts

Leaves of spinach, lettuce, parsley; flower part of broccoli; essential oil of pepper; middle lamella of nuts

Improves immunity, good for eye health

Reflux extraction

[

15

]

Water, aqueous and non-aqueous solvent

60–100 °C

Atmospheric pressure

15 min–2 h

[81][82][83]

Lycopene

Tomato, sweet potato, pink grapefruit, pink guava, watermelon, apricot, papaya, rosehip

Soxhlet extraction

Organic solvents

Skin and pulp of tomato, grapefruit, watermelon, apricot, guava

65–100 °C

Improves eyesight, reduces pain, and strengthens bones

Atmospheric pressure

[16][17]

6–24 h

[84]

Xanthophylls

Pumpkin, papaya, pepper, mushroom

Pressurized liquid extraction

Water, aqueous and non-aqueous solvent

Young leaves of papaya, pumpkin;

essential oil of pepper

50–200 °C

Antioxidant properties, boosts eye health and blood flow

50–300 psi

[18][19]

5–20 min

[

86][87][88]

Cryptoxanthin

Apricot, papaya, peach, cashew apples, seabuckthorn, mandarin, tangerine, lemon

Skin and pulp of cashew apple and citrus fruits

Microwave-assisted extraction

Water, aqueous and non-aqueous solvent

40–120 °C

Maintains pulmonary health, prevents arthritis and inflammation; improves immune response

Atmospheric pressure

[20][21]

30 s–20 min

[

89]

Fucoxanthin

Brown seaweeds, Bacillariophyta, Chromophyta, Macroalgae, Microalgae

Chloroplasts of brown seaweeds

Ultrasound-assisted extraction

Antioxidant, anti-inflammatory, antihypertensive, anticancerous, antidiabetic, antiobesity and radioprotective properties

Water, aqueous and non-aqueous solvent

[10][22]

20–80 °C

Atmospheric pressure

10–60 min

[90][91]

Polyphenols

Pulsed electric field extraction

Water, aqueous and non-aqueous solvent

20–50 °C

1.32–1.64 bar or atmospheric pressure

5 min–48 h

[92][93][94]

Flavones

Parsley, oregano, rosemary, green olive, pumpkin, watermelon, bell pepper, honey, fava beans, chickpea, field pea

Enzyme-assisted extraction

Water, aqueous andnon-aqueous solvent

Essential oils of spices,

pulp of watermelon and pumpkin

33–67 °C

Action against free radicals, protective effects against cardiovascular diseases, cancers, and other age-related diseases

Atmospheric pressure[23][24]

20 min–4 h

[95][96]

[

85

]

Flavanones

Supercritical fluid extraction

Grapefruit, pumelo, mandarin, lemon

Pulp of citrus fruits

Protective effects against cardiovascular diseases, prevention of inflammation and allergies

Supercritical Fluids such as S-CO2, S-H2O

40–80 °C

[25][26]

35–70 MPa

10–60 min

[97][98]

Flavanols

Chocolate, tea, grapes

High hydrostatic pressure extraction

Water, ethanol, glycerol, silicon oil, or a mixture of solvents

Green and black tea leaves

Below 45 °C

Action against free radicals, prevention of inflammation and allergies

100–1000 MPa

[27][28]

3–15 min

[

99][100][101]

Anthocyanidins and anthocyanins

Blueberry, cranberry, pomegranate, red grapes, black soybean, purple corn, red cabbage, raspberry

Flesh of berries, skin of grapes, corn fiber

Protective effects against cardiovascular diseases, prevention of inflammation and allergies

Liquid gas extraction

Liquified petroleum gas (propane, n-butane), dimethyl ether

35 °C

Room temperature or low pressure 200–1000 kPa

[26][29]

20 min

[

10][102]

Polyphenol amides

Natural deep eutectic solvent extraction

Oats, chili, pepper

Deep eutectic solvents such as reline, ethaline, glycerine, etc.

Capsaicinoids in chili pepper,

avenanthramides in oats

25–105 °C

Prevention of inflammation and allergies

Atmospheric pressure

[23][30]

30–60 min

[

103][

Isoprenoids

Limonene

Lemon, lime, orange

Oil of orange

Anti-inflammatory, antioxidant, and anti-stress properties, as well as a neuroprotective role in Alzheimer’s disease

[31][32][33]

Myrcene

Mango, guava, thyme, parsley, bay leaves, lemongrass, cardamom, sweet basil, juniper

Essential oil extract of lemongrass, juniper, cardamom

Anxiolytic, antioxidant, anti-aging, anti-inflammatory, and analgesic properties

[34]

Pinene

Cannabis, turpentine tree, ironwort, sage plant

Oil of cannabis, ironwort, and sage plants

Antibacterial, antitumor, anti-inflammatory, and sedative properties

[35][36]

Phytosterols

Campesterol

Banana, pomegranate, pepper, coffee, grapefruit, cucumber, onion, oat, potato, lemongrass

Pulp of bananas, pomegranate, grapefruit;

essential oil of pepper, lemongrass, etc.

Used in the treatment of allergy, asthma, psoriasis, rheumatoid arthritis, chronic fatigue syndrome, migraine, and menstrual disorders

[37][38][39]

Sitosterol

Avocado, hazelnut, walnut, soybean, olive, canola

Oil of hazelnut, walnut, olive, canola, soybean

Used in the treatment of an enlarged bladder; reduces the risk of cardiovascular disease, promotes anti-cancer properties

[28][37][38]

Stigmasterol

Soybean, calabar bean, and rapeseed

Oil of soybean, calabar bean, and rapeseed

Has a protective effect against gastric and duodenal ulcers, neurological disorders

[37][38][40]

104

]

[

105

]

Campestanol

Soybean, olive, hazelnut, flax, cashew

Oil of soybean, olive, hazelnut, flax, and cashew

Prostate health, hair growth, reduce LDL cholesterol

[37][38]

Sitostanol

Pepper, banana, pomegranate, soybean, olive

Oil of pepper, soybean, and olive; pulps of banana and pomegranate

Reduces chance of heart attack and stroke, improves hair growth

[37][38][42]

Stigmastanol

Hazelnut, olive, corn

Oil of hazelnut and olive, as well as corn fiber

Reduces chance of heart attack and stroke, antioxidant activity

[37][38][43]

Saponins

Dammarane

Black gram, garden pea, pigeon pea

Middle lamella of peas and legumes

Exhibits hypoglycemic, virucidal, and antifungal activity

[44][45]

Tirucallane

Sunflower, almond, walnut

Oil of almond, sunflower, and walnut

Has an effect on the transverse tubular system and sarcoplasmic reticulum at lower concentration (10µg/mL), has an effect on skin inflammation and diarrhea

[46][47]

Oleanane

Common bean, black gram, almond

Middle lamella of legumes and oil of almond

Antimicrobial and hypolipidemic activities; aids in the treatment of chronic diseases

[48]

Dietary fiber

Pectin

Apples, apricots, cherries, oranges, carrots, citrus fruits, rose hip

Peels of citrus fruits,

middle lamella of cell walls of fruits

Lowers LDL cholesterol; cures diarrhea; promotes the generation of peripheral regulatory T cells

[49][50][51]

Cellulose

Rice, wheat, sisal, jute, hemp, corn, flasks

Rice husk,

wheat straw,

kernels of corn

Improves insulin sensitivity, gut microbial viability and diversity; reduces the level of bad cholesterol; reduces free radical damage to cells

[52][53][54]

Lignin

Flaxseeds, parsley, carrots, horseradish), Wheat, tomatoes, berries, broccoli, cabbage, green beans, peaches, peas, Brazil nuts, apples

Seeds of tomatoes and berries, stems of cabbage and broccoli,

bran of wheat

Lowers the risk of cancer, reduces hot flashes in postmenopausal women, protects from cardiovascular diseases

[55][56][57]

Hemicelluloses

Rice, wheat, nuts, legumes, whole grains

Bran of rice and wheat,

middle lamella of legumes, nuts

Improves metabolites from gut microflora; reduces cardiovascular risk

[58][59]

Polysaccharides

Amylose

Corn, rice, quinoa, potato, oats, arrowroot

Starchy endosperm of corn, rice, potato, and oats;

powder of arrowroot

Cures immunodeficiency, cancer, inflammation, hypertension, hyperlipidemia

[60]

Amylopectin

4. Suitability of the Methods for the Extraction of Various Bioactive Compounds

4.1. Carotenoids

Various methods have been adopted by scientists for the extraction of carotenoids. This section discusses the literature on the conditions and suitability of these methods. Yaqoob et al. [106] studied the extraction of carotenoids from dried ripe kinnow (Citrus reticulata) fruit peel using reflux extraction, UAE, and SFE with different concentrations of solvents (50%, 80%, and 100% v/v). To perform reflux extraction, 1 g dried peel was extracted with 50 mL each of ethanol, methanol, and acetone for 4 h at 30 °C. For UAE, a probe sonicator was used for 100 mL each of ethanol, methanol, and acetone, and extraction was carried out for 10 min. SFE was performed at 400 bar and 333 K with CO2 (flow rate of 3 mL/min) along with co-solvents (23% v/v acetone, ethanol, and methanol). The highest recovery of carotenoids (5.17 mg/100 g sample) was observed in SFE while the lowest (0.98 mg/100 g) was found in reflux extraction. Among the solvents, acetone had the highest recovery of carotenoids and β-carotene. Mihalcea et al. [107] studied the SFE of oleoresins and their carotenoids from dried seabuckthorn pomace using CO2. For the extraction, 400 g of sample was loaded into the extraction equipment and pressurized with 99.99% pure CO2 using a high-pressure pump at two different temperatures and pressure conditions, i.e., 35 °C, and 45 MPa for 105 min under the first condition and 37.5 °C and 36.5 Mpa for 105 min for the second condition. The extraction yields obtained under both conditions were 67.6 g/kg d.w. and 63.6 g/kg d.w., respectively. The total carotenoid content in the first extract was 396.12 mg/g d.w. and in the second extract it was 206.73 mg/g d.w. Ordóñez-Santos et al. [108] studied UAE of ground mandarin (Citrus reticulata) epicarp. The sample was mixed with 4 mL of sunflower oil at a sample-to-solvent ratio of 0.0004 g/mL and the extraction was carried out in an Ultrasonic Cleaner (HB-S49 DHT, China) at 240 W, 42 kHz, and 60 °C for 60 min. The total carotenoid content obtained was 140.7 mg/100 g d.w. sample. Purnomo et al. [109] studied the solvent extraction of carotenoid pigments from red fruit juice (Pandanus conoideus Lam) using maceration. The solvents used were 50 mL each of 99.5% ethanol, 99% acetone, and distilled water. Each solvent was separately mixed with 5 g of sample and kept at room temperature for 24 h in the dark. After 24 h, the sample was filtered, and optical density was measured spectrophotometrically at different wavelengths for each solvent. The distilled water extract had an absorption peak of 266 nm, which was less than the visible range. Ethanolic extract gave an absorption peak at 481 nm. Acetone extract gave an absorption peak at 476 nm. When characterized using fluorescence spectroscopy, distilled water extract gave an excitation peak at 290 and 330 nm, and emission peaks were observed at 360 and 430 nm. Ethanolic extract gave an excitation peak at 266 and 294 nm and an emission peak at 343 and 344 nm. Acetone extract gave an excitation peak at 334 and 350 nm and emission peaks at 394 and 561 nm. Since the fluorescence spectra of acetone extract exhibited emission and excitation peaks in the visible range, acetone was found to be best suited for the extraction of carotenoids. Li et al. [110] studied the extraction efficiency of lycopene and β-carotene using acid–base-induced deep eutectic solvent liquid–liquid microextraction (DES-LLME), liquid–liquid microextraction (LLE), and ultrasound-assisted liquid–liquid microextraction (UA-LLE) from juices of watermelon, grapefruit, tomato, and guava. The extraction efficiency of DES-LLME was compared with other organic solvents such as petroleum ether, acetone, and methanol. To perform the extraction, 600 µL of fatty acid deep eutectic solvent (2C9:1C10:1C11) was mixed with 400 μL of ammonium hydroxide (NH3H2O) and vortexed for 30 s. The lycopene and β-carotene content of the extract was measured using HPLC. The extraction efficiency obtained was 96% for β-carotene and 90% for lycopene within 8 min of extraction, while liquid–liquid microextraction (LLE) took 30 min for the complete extraction using acetone, methanol, and petroleum ether and had an extraction efficiency of 75–80%. Ultrasound-assisted LLE using methanol had an extraction efficiency of 80–97% after 15 min of extraction. Deep eutectic solvents had higher extraction efficiency compared to other solvents. Martínez et al. [111] studied the extraction of carotenoids from fresh biomass of yeast cells of Rhodotorula glutinis using PEF. The yeast biomass was resuspended in a citrate phosphate McIlvaine buffer of pH 7.0 to a final concentration of about 108 cells/mL. This was treated for 150 μs at an electric field of 15 kV/cm and total specific energy of 37.12 kJ/kg. This treatment irreversibly electroporated 90% of the cells. Then, the PEF-treated samples were incubated in ethanol at two conditions, i.e., 24 h at 20 °C and pH of 7.0 and 24 h at 25 °C and pH of 8.0. The yield of carotenoids was 240 μg/g d.w. and 375 μg/g d.w., respectively, at either incubation condition.

4.2. Polyphenols

Pavlić et al. [112] studied the NADES extraction of polyphenols from dried wild thyme (Thymus serpyllum L.) dust. For the extraction, 0.05 g of sample was mixed with 20 different NADES, each at a sample-to-solvent ratio of 1:20 mL/mL, and the extraction was carried out for 60 min at 50 °C in a water bath placed in a magnetic stirrer hot plate. To further aid the separation of extract from solvent, 4 mL of water was added and centrifuged at 4000 rpm for 15 min. The use of L-proline (Pro)–glycerin (Gly)–water (H2O) NADE solvent at a mixture ratio of 1:2:1 with a water content of 5.68% extracted out the highest polyphenols compared to other NADE solvents. The yield of polyphenols was 71.43 mg GAE/g when 1 g of sample was extracted using 28 g Pro-Gly-H2O solvent. Popovic et al. [113] studied the green extraction of polyphenols from sour cherry (Prunus cerasus L.) pomace using NADES. To perform the extraction, 300 mg of freeze-dried sample was mixed with 4 mL deep eutectic solvent [1:1 M choline chloride (ChCl) as HBA and malic acid, urea, or fructose as HBD] and the extraction was carried out at 50 °C for 45 min with a stirring speed of 650 rpm. The obtained extract had 3238.32 μg/g of total phenols, 2442.93 μg/g of total anthocyanins, 418.00 μg/g of total flavonoids, and 377.39 μg/g of total phenolic acids. Frohlich et al. [114] optimized UAE for the extraction of phytochemicals from dried leaves of clove (Syzygium aromaticum) using 99.5% ethanol. It was found in the study that extraction using a solvent-to-sample ratio of 35 mL/g at 70 °C and amplitude of 85% for 25 min gave the highest yield. This resulted in a total extract yield of 14.63%, and the yield of eugenol was 2.94 g/kg of leaves. Domínguez-Rodríguez et al. [115] studied EAE of non-extractable bioactive polyphenol from sweet cherry (Prunus avium L.) pomace. In this study, 0.38 g of sweet cherry pomace was extracted using 1 mL methanol at different pH (3–10), temperature (30–70 °C), and enzyme concentrations (1–120 μL/g) for 10–300 min. The optimized conditions were a pH of 10, a temperature of 70 °C, an enzyme concentration of 2 µL/g, and an extraction time of 18.4 min. The recovery of polyphenols at the optimized conditions was 1.1 mg GAE/g sample. Hwang et al. [116] studied the PEF extraction of narirutin and hesperidin from dried Citrus unshiu peels. For this, 30 g of the sample was immersed in distilled water and was treated at a 5 kW pulse generator, 50 Hz pulse frequency, and 3 kV/cm electric field for 60 and 120 s at room temperature. The total yield of extract was higher in the sample treated for 120 s, and the yields of hesperidin and narirutin were 46.96 mg/100 g and 8.76 mg/100 g of the sample, respectively. Velásquez et al. [117] designed 10 NADES via lyophilization and used them for the ultrasound-assisted extraction of anthocyanins from Chilean Luma Chequen (Molina) A. Gray berry. It was found in the study that the highest recovery of total anthocyanins (3.30 mg/g DW) was obtained for NADESs prepared using lactic acid and glucose in the ratios 8:1, followed by NADESs prepared using choline chloride: glycine (4:6) (3.30 mg/g DW), glycine: glucose (8:1) (3.06 mg/g DW) and tartaric acid: glycine (4:1) (3.03 mg/g). The anthocyanin content of extracts based on NADES was significantly higher than ethanol (1.16 mg/g DW), except for NADESs prepared using tartaric acid: glycine (1:2) (0.81 mg/g DW). Grdiša et al. [118] studied the extraction efficiency of pyrethrins from dried flower heads of Dalmatian pyrethrum (Tanacetum cinerariifolium/Trevir. Sch. Bip.) using maceration, UAE, and matrix solid-phase dispersion (MSPD). A sample size of 0.25 g was used in all three extraction methods. Maceration extraction was performed using different solvents, i.e., acetone, ethanol, and ethyl acetate at different volumes, i.e., 5, 7, 9, and 11 mL, at different extraction times, i.e., 0.5, 1, 2, and 3 h, at the stirrer rotational speed of 200, 300, 400, and 500 rpm. UAE was carried out using 5 mL acetone at 50 °C for 60 min at 1200 W and 35 kHz. In MSPD, the sample was mixed with 0.50 g of florisil and 0.40 g of Na2SO4, after which florisil was activated at 160 °C and washed with n-hexane and methanol. It was then treated with solvents such as acetone and ethyl acetate at 1:1 (v/v) and extracted using a solid phase extractor. It was found in the study that the highest extraction efficiency of pyrethrin was obtained in maceration (0.62%), followed by MSPD (0.59%) and UAE (0.49%). Sharma et al. [119] optimized MAE for the extraction of phytochemicals such as phenols, flavonoids, ascorbic acid, and tannins from dried fruits of Ficus racemosa. The optimized conditions for the extraction were sample to water ratio of 1:15, pH of 3.5, microwave power of 360.55 W, and extraction time of 30 s. These extraction conditions resulted in the extraction of 31.19 mg/100 mL of ascorbic acid, 35.14 mg/100 mL of gallic acid, 14.06 mg/100 mL of tannic acid, 50.86 mg/100 mL of chlorogenic acid, 36.96 mg/100 mL of quercetin. Oroian et al. [120] evaluated the extraction efficiency of flavonoids and polyphenols from crude pollen (collected from a local beekeeper in Suceava County, Romania) using UAE. To perform the extraction, 30 g of pollen sample was mixed with 1 liter of 80% methanol and extraction was carried out at 40.85 °C and 100% amplitude for 14.30 min. The extraction of total phenols and total flavonoids was 366.1 mg GAE/100 g and 592.2 mg QE/g of the sample, respectively. De Queiroz et al. [121] optimized the MAE for the extraction of phenols and tannins from the dried stem bark of Stryphnodendron adstringens. The extraction was carried out by adding 0.075 g of sample in 1 mL of water and heating it at 106–134 °C for 0.48–2.12 min. These conditions extracted out 15.91–18.69% tannins and 16.36–22.12% phenols from the studied sample. In a study conducted by Azman et al. [67] on the extraction of free and bound phenolics from dried black currant (Ribes nigrum L.) skins, it was found that acetic buffer solvent resulted in the highest free anthocyanin (1712.3 mg/100 g), free hydroxycinnamic acid (268 mg/100 g), total phenolic content (3702 mg GAE/100 g), and DPPH inhibition activity (60.7%) compared to other solvents, i.e., water, methanol and a mixture of methanol and water. The use of acetic acid as a co-solvent with other solvents such as water and ethanol has also been reported to extract the phytochemicals from colored vegetables [122]. Jamaludin et al. [99] optimized the extraction of bioactive compounds from noni fruits using high hydrostatic pressure. This study was carried out in two parts. In the first part, the effect of each extraction parameter (ethanol concentration, pressure, and extraction time) was studied individually on the yield of bioactive compounds (scopoletin, alizarin, and rutin), and in the second part, the combined effect of the extraction parameters was studied on the yield of bioactive compounds using the Box-Behnken Design of RSM. The highest yield of bioactive compounds, i.e., scopoletin (82.4%), alizarin (77.2%), and rutin (82.2%), were found at 544 MPa, with an extraction time of 15 min and ethanol concentration of 65%. The extraction of phenyletanes and phenylpropanoids of Rhodiola rosea L. using NADES was studied by Shikov et al. [123]. The highest concentration of total phenyletanes and phenylpropanoids (26.10 mg/g) was obtained using NADES prepared using L-lactic acid, fructose, and water in the ratios 5:1:11 mL/mol when the particle size of Rhodiola rosea L. rhizome was in between 0.5–1 mm and the extraction was carried out for 154 min at 22 °C and extraction modulus of 40. Razboršek et al. [103] performed choline chloride-based UAE NADES extraction of phenolic compounds from chokeberry (Aronia melanocarpa) and compared the results with those obtained from 80% methanolic extract. The highest total phenols (36.15 mg GAE/g DW) and total flavonoids (4.71 mg rutin/g DW) were obtained for NADES prepared using choline chloride, fructose, and water in the ratios 2:1:1. This was significantly higher than 80% methanol, i.e., 27.11 mg GAE/g DW for total phenols and 3.37 mg rutin/g DW for flavonoids. The application of methyl acetate under pressurized conditions for the extraction of Crambe seed oil has been reported to have higher phytosterol and tocopherol values compared to the Soxhlet method [124] Castro-López et al. [125] studied polyphenol extraction from pomegranate (Punica granatum) peels, walnut (Juglans regia) shells, hojasen (Cassia fistula) leaves, and moringa (Moringa oleifera) leaves using different extraction methods, i.e., maceration, decoction, UAE, and MAE. For maceration, 0.2 g of sample was treated with 10 mL deionized water at a sample-to-solvent ratio of 1:50 at room temperature in a magnetic stirrer for 2 h. For decoction, 0.2 g of sample was treated with 10 mL deionized water at a sample-to-solvent ratio of 1:50 in an oven at 60 °C for 2 h. The UAE was carried out at 25 °C in a sonicated water bath for 60 min using a sample-to-solvent (deionized water) ratio of 1:50. For MAE, deionized water at a sample-to-solvent ratio of 1:50 was used at 550 W and 70 °C for 90 s. Higher polyphenol content was obtained using MAE followed by decoction, UAE, and maceration methods. Total polyphenol yields of 6.4–18.92 mg GAE/g, 1.17–12.8 mg GAE/g, 2.73–15.19 mg GAE/g, and 1.68–12.69 mg GAE/g were obtained for pomegranate peel, walnut shell, moringa leaves, and hojasen leaves, respectively. Jovanovic’ et al. [126] extracted polyphenols from the air-dried aerial part of Thymus serpyllum L. using maceration, heat-assisted extraction (HAE), and UAE. Maceration was carried out using ethanol and water solutions containing 30%, 50%, 70%, and 96% ethanol. The particle sizes of the powder used for extraction were 0.3, 0.7, and 1.5 mm, and to perform the extraction, solid-to-solvent ratios of 1:10, 1:20, and 1:30 were used for the extraction times of 5, 15, 30, 60 and 90 min. In HAE, solvent concentrations and sample-to-solvent ratios were the same as that of maceration; however, the extraction was carried out at 80 °C for 5, 15, and 30 min in an incubator shaker. In UAE, solvent type, solid-to-solvent ratio, particle size, and extraction time were similar to those of HAE. The extraction was carried out at 25 °C and 80% amplitude and a 750 W output ultrasonic processor with a 20 kHz converter having a solid titanium probe of 19 mm diameter. The total phenolics extracted using maceration, HAE, and UAE were 19.56 mg GAE/L, 22.60 mg GAE/L, and 24.94 mg GAE/L, respectively. Porto and Natalino [127] studied the SFE of polyphenols from dried white grape Marc (Vitis vinifera) seeds. They used 100 g of sample in an SFE pilot plant (SCF100 series 3 PLC-GR-DLMP, Separeco S.R.L, Pinerolo, Italy) equipped with a 1 L extraction vessel, and the extraction was carried out for 13 min at a pressure of 80 bar, a temperature of 40 °C, and a CO2 flow rate of 6 kg/h along with 57% v/v of ethanol–water (20% w/w) mixture as co-solvent. The total polyphenol yield in this extraction was 7132 mg GAE/100 g DM. The extraction of phlorotannins from brown algae using NADES is reported by Obluchinskaya et al. [128]. The study reported that the use of aqueous NADES solutions (50–70%) based on choline chloride with added lactic or malic acid and betaine and malic acid gave a 6—72% yield of phlorotannins. Sharif and Bennet [129] compared maceration and reflux methods for the extraction of polyphenols from freeze-dried ginger rhizomes using various solvents viz. ethanol, methanol, and acetone. For maceration, 10 g of sample was used with 300 mL of solvent and placed in an orbital shaker for 8 h. In the reflux extraction, a 2.5 g sample was extracted with 50 mL solvent at 90 °C for 30 min. The total phenol contents obtained using ethanol for the maceration and reflux extraction were 263 and 205.4 mg/100 g GAE, respectively. In the case of acetone, the total phenols yield was 216 mg/100 g GAE for maceration and 184 mg/100 g GAE for reflux extraction, while when using methanol it was 148 mg/100 g GAE for maceration and 95 mg/100 g GAE for reflux. This shows the lower extraction efficiency of reflux extraction compared to maceration.

4.3. Phytosterols

De Aquino et al. [130] studied the effect of thermal pre-treatment on the enzyme (protease)-assisted aqueous extraction and yield of phytosterols from sunflower (Helianthus annuus L.) seeds. The thermal pre-treatment was performed by immersing 150 g of whole seeds in distilled water at room temperature in the ratio of 1:3 (w/v). Excess water was removed after 3 h and the sample was placed in an oven with air circulation (Marconi, Model MA035) at 120 °C for 60 min. A commercial enzymatic preparation, i.e., Alcalase® 2.4 L FG was used as a source of protease enzyme. The extraction for both thermally pre-treated and untreated samples was carried out for 3 h at 40 °C, pH of 8, and enzyme concentration of 9% v/v. The total yield of the oil using this method was 15.59%. The total yield of phytosterols in the oil extracted without thermal treatment was 149.41 mg/100 g oil, and the major phytosterols were campesterol (15.80 mg/100 g), stigmasterol (21.46 mg/100 g), γ-sitosterol (12.07 mg/100 g), and β-sitosterol (100.07 mg/100 g). The yield of total phytosterols from the thermally pre-treated samples was 133.66 mg/100 g. The major phytosterols obtained were campesterol (15.99 mg/100 g), stigmasterol (18.88 mg/100 g), γ-sitosterol (8.72 mg/100 g), and β-sitosterol (90.08 mg/100 g). Hien and Minh [131] compared UAE and enzyme-assisted UAE for the extraction of oil and phytosterols from dried pumpkin (Cucurbita pepo L) seeds. The extraction was carried out using hexane for 4.5 h at a sample-to-solvent ratio of 1:6, frequency of 40 kHz, and temperature of 60 °C. In enzyme-assisted UAE, commercial enzyme Alcalase® 2.4 L FG with enzyme activity of 3.9 U/mL was used along with the above parameters. The oil extraction yield was 95.46% in UAE, while 91.87% was obtained from enzyme-assisted UAE. The phytosterol content was 2017.5 mg/100 mL in UAE-extracted oil and 2327.7 mg/100 mL in oil extracted from enzyme-assisted UAE. UAE was found to be effective for oil extraction, while the phytosterol extraction was more efficient with the enzyme-assisted UAE. Jalani et al. [132] extracted phytosterols from sludge palm oil (also known as palm acid oil) and empty fruit bunch (Elaeis guineensis) residual oil. In this study, a 5 g sample was extracted at 90 °C for 1 h with 50 mL of ethanol at the sample-to-solvent ratio of 1:10. The quantity of the phytosterols in the sludge palm oil was 500 ppm and the content of phytosterols in unsaponifiable form was 6.19%. In empty fruit bunch residual oil, phytosterol content was 450 ppm and the phytosterols in unsaponifiable form were 4.58%. Jafarian Asl et al. [133] compared Soxhlet and SFE extraction of phytosterols from rapeseed (Brassica napus L.) oil. Soxhlet extraction was carried out using a 15 mg sample in 150 mL ethanol at the sample-to-solvent ratio of 1:10 at different temperatures (40, 60, and 80 °C) for 1 h. SFE was carried out for 1 h with CO2 and co-solvent ethanol having flow rates of 5 mL/min and 0.5 mL/min, respectively. This extraction was carried out at different pressures ranging from 100–400 bar. The highest yield (87%) of phytosterols was obtained in Soxhlet extraction at 40 °C and SFE at 350 bar. The lowest phytosterol yield (21%) was obtained with SFE at 100 bar. Ibrahim et al. [134] studied the MAE extraction of β-sitosterol from cocoa (Theobroma cacao) shell waste. The extraction was carried out using a 100 g sample with 300 mL, 99% ethanol in the sample to solvent ratio of 1:3 at 500 W and 70 °C for 10 min. The total extract obtained was 13% based on the one-factor-at-a-time (OFAT) approach and the sitosterol present was 3546.1 mg/100 g extract.

4.4. Saponins

Li et al. [135] studied the UAE of saponins from powdered Aralia taibaiensis root bark. The extraction was carried out in a water-bath sonicator with different ethanolic concentrations (50, 60, 70, 80, and 90%), time durations (10, 20, 30, 40, and 50 min), temperatures (40, 50, 60, 70, and 80 °C), sample to solvent ratios (5, 10, 15, 20, and 25 g/mL), ultrasound power (100, 200, 300, 400, and 500 W) and number of extractions (1, 2, 3, 4, and 5). The highest total saponin (11.45%) content was obtained when 5 g of sample was extracted with 75 mL of 73% ethanol at 400 W and 61 °C for 34 min. Liu et al. [136] studied the EAE of saponins from powdered Acanthopanax senticosus. The extraction was carried out at different enzyme concentrations (1000, 5000, and 9000 U/g), time durations (45, 55, and 65 min), temperatures (40, 50, and 60°C), and solvent pH values (5.4, 6, and 6.6). The highest extraction yield of saponins (17.8 mg/g sample), was obtained when 2 g of sample was extracted with 6963 U/g of enzyme mixture (cellulase and pectinase at a ratio of 2:3) at pH 6 and a temperature of 53.7 °C for 60 min. Yang et al. [137] studied the extraction of four bioactive steroidal saponins (protodioscin, protogracillin, pseudoprotodioscin, and pseudoprotogracillin) from the dried rhizome of Dioscorea nipponica, also known as Dioscoreae Nipponicae Rhizoma (DNR), using NADES. A mixture containing ChCl and malonic acid in a molar ratio of 1:1 with 30% water was used as the NADE solvent. For a sample weighing 50 mg, the optimal extraction conditions were 1 mL NADE solvent, an extraction time of 23.5 min, a liquid–solid ratio of 57.5 mL/g, a water content of 54%, and ultrasonic conditions of 300 W and 40 kHz. The recovery yield of four steroidal saponins was between 98.8 and 107.5% compared to standard steroidal saponins. The extract consisted of 64.99 mg/g of total saponins where 29.39 mg/g was protodioscin, 15.86 mg/g was protogracillin, 9.71 mg/g was pseudoprotodioscin, and 3.66 mg/g was pseudoprotogracillin. Ramli et al. [138] studied the MAE of saponins from dried furcraea (Furcraea selloa var. marginata) leaves using water, ethyl acetate, and ethanol. The extraction was carried out using a 3 g sample in 200 mL solvent at a ratio of 1:24, frequency of 2.45 GHz, and power of 1000 W at 90 °C for 9 min. The extraction yields obtained from aqueous, ethyl acetate, and ethanolic extract were 5.77%, 8.07%, and 6.67%, respectively. The saponin contents in the samples extracted using water, ethyl acetate, and ethanol were 0.0514 g/mL, 0.0453 g/mL, and 0.0344 g/mL extract, respectively.

4.5. Isoprenoids

Lanjekar and Rathod [139] optimized the extraction of glycyrrhizic acid from Glycyrrhiza glabra (Liquorice root) powder using choline chloride (ChCl): lactic acid (1:1), ChCl: dextrose (2:1), ChCl: glycerol (min1:1), ChCl: malic acid (1:1), ChCl: citric acid (1:1), ChCl: oxalic acid (1:1), and ChCl: succinic acid (1:1) as different natural deep eutectic solvents. In this extraction, 2 g licorice powder having a moisture content of 7.78% was treated with 20 mL NADES in an overhead stirrer for 60 min at 400 rpm and 30 °C. The mixture was then centrifuged at 8000 rpm for 10 min and analyzed using HPLC. The highest glycyrrhizic acid yield was 43.65 mg/g of the sample using ChCl: succinic acid as solvent. The yield of glycyrrhizic acid was 42.82 mg/g using ChCl: lactic acid as solvent, 23.25 mg/g using ChCl: dextrose, 14.37 mg/g using ChCl: glycerol, 30.67 mg/g using ChCl: citric acid, 36.70 mg/g using ChCl: malic acid, and 39.60 mg/g using ChCl: oxalic acid. The extraction of glycyrrhizic acid from liquorice roots using NADES has also been reported by Shikov et al. [140]. The yields of glycyrrhizic acid in NADES based on sucrose and lactic acid (3:1), sorbitol and lactic acid (3:1), and choline chloride and lactic acid (1:3) were higher (38–60 mg/g) than its yield in water (<30 mg/g). Rodrigues et al. [141] extracted triterpenoids from dried leaves of Acacia dealbata using SFE and Soxhlet extraction. The sample was dried using a forced convection oven at 35 °C for 72 h to a moisture content of 4.5% wt. For Soxhlet extraction, different solvents such as 99.5% ethanol, 99% hexane, 99% ethyl acetate, and 99% dichloromethane were used. In this study, 3 g of sample was used with 180 mL solvent for 6 h at 39–78 °C. For SFE, CO2, CO2: ethanol (95:5 wt.%), and CO2:ethyl acetate (95:5 wt.%) were used as solvents. For extraction, a 25 g sample was loaded into the extraction chamber of a lab-scale Speed Helix SFE System at a flow rate of 12 g/min for 6 h at 40–80 °C. From Soxhlet extraction, the highest total extraction yield obtained was 11.58% using ethanol as solvent. The highest triterpenoid yield obtained was 8201 mg/kg of extract using ethyl acetate as a solvent and 6259 mg/kg of extract using ethanol as a solvent. From SFE, the highest yield was 1.76% using CO2 as solvent. The highest triterpenoid yield obtained was 4719 mg/kg of extract using CO2: ethanol as solvent and a triterpenoid yield of 4366 mg/kg of extract using CO2:ethyl acetate as solvent. Grdiša et al. [118] studied the extraction efficiency of pyrethrins from dried flower heads of Dalmatian pyrethrum (Tanacetum cinerariifolium/Trevir./Sch. Bip.) using maceration, UAE, and matrix solid-phase dispersion (MSPD). A sample size of 0.25 g was used in all three extraction methods. Maceration extraction was performed using different solvents, i.e., acetone, ethanol, and ethyl acetate at different volumes, i.e., 5, 7, 9, and 11 mL, at different extraction times, i.e., 0.5, 1, 2, and 3 h at stirrer rotational speeds of 200, 300, 400, and 500 rpm. UAE was carried out using 5 mL acetone at 50 °C for 60 min at 1200 W and 35 kHz. In MSPD, the sample was mixed with 0.50 g of florisil and 0.40 g of Na2SO4, (florisil was activated at 160 °C and washed with n-hexane and methanol). It was then treated with solvents such as acetone and ethyl acetate at 1:1 (v/v) and extracted using a solid phase extractor. It was found in the study that the highest extraction efficiency of pyrethrin was obtained in maceration (0.62%), followed by MSPD (0.59%) and UAE (0.49%).

4.6. Polysaccharides and Dietary Fiber

Gong et al. [142] studied the SFE of polysaccharides from dried fallen Ginkgo biloba leaf powder. For the extraction, a 20 g sample was placed in a supercritical extraction device and the extraction was carried out using SC-CO2 and 15% co-solvent having strengths of 60, 70, and 80% and at the temperatures of 50, 60, and 70 °C, pressures of 35, 40, and 45 MPa, and time intervals of 80, 100, and 120 min. The extract was centrifuged at 6000 rpm for 15 min and analyzed. The highest yield (10.13 g/100 g) of polysaccharides was obtained with 68% co-solvent at the extraction conditions of 42 MPa, 63°C, and 99 min. García et al. [143] studied pressurized liquid extraction of total dietary fiber from dried pomegranate (Punica granatum L.) peel and fruit. For the extraction, 3.75 g of powdered sample was mixed with 11.25 g of sand and the extraction was carried out in a pressurized liquid extractor at 1500 psi for 20 min. The total dietary fiber extracted was analyzed using an enzymatic gravimetric method and a yield of 30% was obtained from the peel and 18% from the fruit. Hussain et al. [144] optimized the UAE of soluble dietary fiber from dried sea buckthorn (Hippophae rhamnoides L.) pomace powder. Samples were pretreated by mixing with 0.1% citric acid at the sample-to-acid ratio of 1:25 and incubated in a water bath at 80 °C for 1 h. Extraction was carried out using a Digital Sonifier® S450 CE (Richmond Newtown, VA, USA) attached with a 13 mm diameter disruptor horn. The extraction was carried out at different sonication temperatures (60, 70, and 80 °C), powers (100, 130 and 160 W), and time intervals (30, 45, and 60 min). The extract so obtained was further centrifuged at 6000 rpm for 10 min to obtain the dietary fiber. The highest extraction yield obtained was 17.82% under the conditions of 130 W and 70 °C for 45 min. Rivas et al. [145] optimized the SFE of dietary fiber from dried pomegranate (Punica granatum L.) peel. The extraction was carried out using 40 g powdered sample inside a 100 mL stainless steel column with a CO2 flowrate of 2 L/min and different extraction conditions such as pressure (250, 275, and 300 bar), temperature (45, 50, and 55 °C), and time (2, 3, and 4 h). Dietary fiber was estimated using the alcohol–insoluble residue method. The highest dietary fiber obtained was 49.37 g/100 g of the sample under the extraction conditions of 45 °C and 300 bar for a duration of 2.2 h. Douard et al. [146] optimized NADES extraction of cellulose nanocrystals from cotton sheets obtained from the paper industry. The extraction was carried out using a 2 mg cotton sheet with a mixture of 63 g oxalic acid and 69.8 g ChCl as NADE solvent under differing conditions such as cellulose concentrations (1, 1.5, and 2%), temperature (60, 75.5, and 95 °C), and time intervals (2, 9, and 16 h). After extraction, cellulose was washed and filtered out through a 1 µm membrane using 200 mL of deionized water, and the filtrate was centrifuged at 10,000 rpm for 15 min. The highest yield of cellulose nanocrystals (35.5%) with a crystallinity index of 80% was obtained at 95 °C for 6 h with a 2% cellulose concentration. Gan et al. [147] studied the extraction of soluble dietary fiber from dried grapefruit (Citrus paradisi) peel powder using microwave–enzymatic treatment (MET), microwave–sodium hydroxide treatment (MST), and microwave–ultrasonic treatment (MUT). Microwave treatment was carried out using a 3 g sample in each of eight polyfluoroalkoxy tubes that were treated using a microwave cracker at 500 W and 80 °C for 40 min. For MST, a 5 g microwave-treated sample was mixed with 1% NaOH using a magnetic stirrer in a water bath at 200 rpm and 50 °C for 30 min and then centrifuged at 4800 rpm for 10 min. For MET, a 5 g microwave-treated sample was mixed with 240 mg cellulase (3000 U/g) at a pH of 4.5 and 1% heat stable α-amylase at pH 5, then incubated in a water bath for 30 min at 90 °C. When the temperature reached 60 °C, the pH was maintained at 6, and 0.05% papain was added and incubated at this temperature for 30 min. For MUT, a 5 g microwave-treated sample was placed in a Sonicator JY92-Ⅱ (Ningbo Scientz. Biotechnology Co. LTD, Ningbo, China) at 200 W and 25 °C for 10 min. The yields of the dietary fiber from MST, MET, and MUT were 17.19 g/100 g, 9.13 g/100 g, and 8.35 g/100 g samples, respectively. Cheikh Rouhou et al. [148] compared different solvents for the extraction of dietary fiber from ground cactus (Opuntia ficus indica) rackets. Water and ethanol were used as a solvent in maceration extraction and lemon juice as a solvent in steam extraction. For maceration using water, hot water was used for extraction at the sample-to-solvent ratio of 1:30 at 100 °C for 30 min and 1 h. For maceration using ethanol, 80% ethanol was used at the sample-to-solvent ratio of 1:10 for 30 min and 1 h at room temperature. For steam extraction using lemon juice, a sample-to-solvent ratio of 1:30 at 220 °C and 2 bar pressure at pH 2 were used for 30 min and 1 h. The highest fiber content (86.66%) was obtained in lemon juice steam extraction followed by maceration with water (85.81%) and ethanol (84.88%) after 1 h of extraction.

References

  1. Sharma, B.R.; Kumar, V.; Gat, Y.; Kumar, N.; Parashar, A.; Pinakin, D.J. Microbial maceration: A sustainable approach for phytochemical extraction. 3 Biotech 2018, 8, 401.
  2. Jaeger, R.; Cuny, E. Terpenoids with special pharmacological significance: A review. Nat. Prod. Commun. 2016, 11, 1934578X1601100946.
  3. Rowles, J.L., 3rd; Erdman, J.W., Jr. Carotenoids and their role in cancer prevention. Biochimica et Biophysica Acta. Mol. Cell Biol. Lipids. 2020, 1865, 158613.
  4. Jiang, Y.; Chen, L.; Taylor, R.N.; Li, C.; Zhou, X. Physiological and pathological implications of retinoid action in the endometrium. J. Endocrinol. 2018, 236, R169–R188.
  5. Cooperstone, J.L.; Schwartz, S.J. Recent insights into health benefits of carotenoids. In Handbook on Natural Pigments in Food and Beverages; Carle, R., Schweigget, R.M., Eds.; Woodhead Publishing: Cambridge, UK, 2016; pp. 473–497.
  6. Vallverdú-Coll, N.; Ortiz-Santaliestra, M.E.; Mougeot, F.; Vidal, D.; Mateo, R. Sublethal Pb exposure produces season-dependent effects on immune response, oxidative balance and investment in carotenoid-based coloration in red-legged partridges. Environ. Sci. Technol. 2015, 49, 3839–3850.
  7. Yuan, Y.; Macquarrie, D. Microwave assisted extraction of sulfated polysaccharides (fucoidan) from Ascophyllum nodosum and its antioxidant activity. Carbohydr. Polym. 2015, 129, 101–107.
  8. Shikov, A.N.; Mikhailovskaya, I.Y.; Narkevich, I.A.; Flisyuk, E.V.; Pozharitskaya, O.N. Methods of extraction of medicinal plants. In Evidence-Based Validation of Herbal Medicine; Elsevier: Amsterdam, The Netherlands, 2022; pp. 771–796.
  9. Carreira-Casais, A.; Otero, P.; Garcia-Perez, P.; Garcia-Oliveira, P.; Pereira, A.G.; Carpena, M.; Soria-Lopez, A.; Simal-Gandara, J.; Prieto, M.A. Benefits and drawbacks of ultrasound-assisted extraction for the recovery of bioactive compounds from marine algae. Int. J. Environ. Res. Public Health. 2021, 18, 9153.
  10. Quitério, E.; Grosso, C.; Ferraz, R.; Delerue-Matos, C.; Soares, C. A Critical Comparison of the Advanced Extraction Techniques Applied to Obtain Health-Promoting Compounds from Seaweeds. Marine Drug. 2022, 20, 677.
  11. Zeece, M. Food colorants. In Introduction to the Chemistry of Food; Zeece, M., Ed.; Academic Press: Cambridge, MA, USA, 2020; pp. 313–344.
  12. Nagarajan, J.; Ramanan, R.N.; Raghunandan, M.E.; Galanakis, C.M.; Krishnamurthy, N.P. Carotenoids. In Nutraceutical and Functional Food Components: Effects of Innovative Processing Techniques; Galanakis, C.M., Ed.; Academic Press: Cambridge, MA, USA, 2017; pp. 259–296.
  13. Bogacz-Radomska, L.; Harasym, J. β-Carotene—Properties and production methods. Food Qual. Safe 2018, 2, 69–74.
  14. Grune, T.; Lietz, G.; Palou, A.; Ross, A.C.; Stahl, W.; Tang, G.; Thurnham, D.; Yin, S.A.; Biesalski, H.K. Beta-carotene is an important vitamin A source for humans. J. Nutr. 2010, 140, 2268S–2285S.
  15. Eisenhauer, B.; Natoli, S.; Liew, G.; Flood, V. Lutein and zeaxanthin—Food sources, bioavailability and dietary variety in age-related macular degeneration protection. Nutrients 2017, 9, 120.
  16. Imran, M.; Ghorat, F.; Ul-Haq, I.; Ur-Rehman, H.; Aslam, F.; Heydari, M.; Shariati, M.A.; Okuskhanova, E.; Yessimbekov, Z.; Thiruvengadam, M.; et al. Lycopene as a Natural Antioxidant Used to Prevent Human Health Disorders. Antioxidants 2020, 9, 706.
  17. Przybylska, S. Lycopene—A bioactive carotenoid offering multiple health benefits: A review. Int. J. Food Sci. Tech. 2019, 55, 11–32.
  18. Aziz, E.; Batool, R.; Akhtar, W.; Rehman, S.; Shahzad, T.; Malik, A.; Shariati, M.A.; Laishevtcev, A.; Plygun, S.; Heydari, M.; et al. Xanthophyll: Health benefits and therapeutic insights. Life Sci. 2020, 240, 117104.
  19. Sara Sara, G.Y.; Dauda, S.; Emmanuel, A.; Bhutto, Y.Y.; Joseph, I. Phytochemical screening and antimicrobial activity of leaf and stem-bark aqueous extracts of Diospyros mespiliformis. Int. J. Biochem. Res. Rev. 2018, 22, 1–8.
  20. Jiao, Y.; Reuss, L.; Wang, Y. β-Cryptoxanthin: Chemistry, occurrence, and potential health benefits. Curr. Pharmacol. Rep. 2019, 5, 20–34.
  21. Furukawa, H. Cultivation technology for vegetable and herb production. In Plant Factory Using Artificial Light: Adapting to Environmental Disruption and Clues to Agricultural Innovation; Anpo, M., Fukuda, H., Wada, T., Eds.; Elsevier: Amsterdam, The Netherlands, 2019; pp. 15–23.
  22. Wang, X.; Ma, Y.; Xu, Q.; Shikov, A.N.; Pozharitskaya, O.N.; Flisyuk, E.V.; Liu, M.; Li, H.; Duez, P. Flavonoids and saponins: What have we got or missed? Phytomedicine 2023, 109, 154580.
  23. Ballard, C.R.; Maróstica, M.R. Health Benefits of Flavonoids. In Bioactive Compounds; Woodhead Publishing: Cambridge, UK, 2019; pp. 185–201.
  24. Hostetler, G.L.; Ralston, R.A.; Schwartz, S.J. Flavones: Food Sources, Bioavailability, Metabolism, and Bioactivity. Adv. Nutr. 2017, 8, 423–435.
  25. Ana, C.C.; Jesús, P.V.; Hugo, E.A.; Teresa, A.T.; Ulises, G.C.; Neith, P. Antioxidant capacity and UPLC–PDA ESI–MS polyphenolic profile of Citrus aurantium extracts obtained by ultrasound assisted extraction. J. Food Sci. Tech. 2018, 55, 5106–5114.
  26. Tomas-Barberan, F.A.; Clifford, M.N. Flavanones, chalcones and dihydrochalcones—Nature, occurrence and dietary burden. J. Sci. Food Agric. 2000, 80, 1073–1080.
  27. Liu, Z.; Bruins, M.E.; de Bruijn, W.J.C.; Vincken, J.P. A comparison of the phenolic composition of old and young tea leaves reveals a decrease in flavanols and phenolic acids and an increase in flavonols upon tea leaf maturation. J. Food Compos. Anal. 2020, 86, 103385.
  28. Bonetti, F.; Brombo, G.; Zuliani, G. Nootropics, functional foods, and dietary patterns for prevention of cognitive decline. In Nutrition and Functional Foods for Healthy Aging; Watson, R.R., Ed.; Academic Press: Cambridge, MA, USA, 2017; pp. 211–232.
  29. Guan, L.; Fan, P.; Li, S.H.; Liang, Z.; Wu, B.H. Inheritance patterns of anthocyanins in berry skin and flesh of the interspecific population derived from teinturier grape. Euphytica 2019, 215, 1–14.
  30. Tsao, R. Chemistry and biochemistry of dietary polyphenols. Nutrients 2010, 2, 1231–1246.
  31. Shahbazi, Y.; Shavisi, N. Limonene. In A Centum of Valuable Plant Bioactives; Mushtaq, M., Farooq, A., Eds.; Academic Press: Cambridge, MA, USA, 2021; pp. 77–91.
  32. Eddin, L.B.; Jha, N.K.; Meeran, M.; Kesari, K.K.; Beiram, R.; Ojha, S. Neuroprotective potential of limonene and limonene containing natural products. Molecules 2021, 26, 4535.
  33. Klimek-Szczykutowicz, M.; Szopa, A.; Ekiert, H. Citrus limon (lemon) phenomenon-a review of the chemistry, pharmacological properties, applications in the modern pharmaceutical, food, and cosmetics industries, and biotechnological studies. Plants 2020, 9, 119.
  34. Surendran, S.; Qassadi, F.; Surendran, G.; Lilley, D.; Heinrich, M. Myrcene-What are the potential health benefits of this flavouring and aroma agent? Front. Nutr. 2021, 8, 699666.
  35. Salehi, B.; Upadhyay, S.; Orhan, E.I.; Jugran, A.K.; Jayaweera, S.L.P.; Dias, D.A.; Sharopov, F.; Taheri, Y.; Martins, N.; Baghalpour, N.; et al. Therapeutic potential of α- and β-Pinene: A miracle gift of nature. Biomolecules 2019, 9, 738.
  36. Russo, E.B. Taming THC: Potential cannabis synergy and phytocannabinoid-terpenoid entourage effects. British J. Pharmacol. 2011, 163, 1344–1364.
  37. Bot, A. Phytosterols. In Encyclopedia of Food Chemistry; Melton, L., Varelis, P., Sahahidi, F., Eds.; Elsevier: Amsterdam, The Netherlands, 2019; pp. 225–228.
  38. National Center for Biotechnology Information. PubChem Compound Summary for CID 119394, Campestanol. 2022. Available online: https://pubchem.ncbi.nlm.nih.gov/compound/Campestanol (accessed on 10 April 2022).
  39. Ho, X.L.; Loke, W.M. Dietary plant sterols supplementation increases in vivo nitrite and nitrate production in healthy adults: A randomized, controlled study. J. Food Sci. 2017, 82, 1750–1756.
  40. Sudeep, H.V.; Thomas, J.V.; Shyamprasad, K. A double blind, placebo-controlled randomized comparative study on the efficacy of phytosterol-enriched and conventional saw palmetto oil in mitigating benign prostate hyperplasia and androgen deficiency. BMC Urol. 2020, 20, 86.
  41. Tovey, F. Duodenal ulcer and diet in Sub-Saharan Africa. In Digestive Diseases in Sub-Saharan Africa: Changes and Challenges; Segal, I., Ed.; Academic Press: Cambridge, MA, USA, 2019; pp. 53–65.
  42. Karim, N.; Khan, I.; Abdelhalim, A.; Halim, S.A.; Khan, A.; Al-Harrasi, A. Stigmasterol can be new steroidal drug for neurological disorders: Evidence of the GABAergic mechanism via receptor modulation. Phytomed. Int. J. Phytother. Phytopharmacol. 2021, 90, 153646.
  43. Liwa, A.C.; Barton, E.N.; Cole, W.C.; Nwokocha, C.R. Bioactive plant molecules, sources and mechanism of action in the treatment of cardiovascular disease. In Pharmacognosy; Academic Press: Cambridge, MA, USA, 2017; pp. 315–336.
  44. Akihisa, T.; Zhang, J.; Tokuda, H. Potentially chemopreventive triterpenoids and other secondary metabolites from plants and fungi. Stud. Nat. Prod. Chem. 2016, 51, 1–50.
  45. Brüll, F.B.; Mensink, R.P.; Steinbusch, M.F.; Husche, C.; Lütjohann, D.; Wesseling, G.J.; Plat, J. Beneficial effects of sitostanol on the attenuated immune function in asthma patients: Results of an in vitro approach. PLoS ONE 2012, 7, e46895.
  46. Zhang, B.; Hu, X.; Wang, H.; Wang, R.; Sun, Z.; Tan, X.; Liu, S.; Wang, H. Effects of a dammarane-type saponin, ginsenoside Rd, in nicotine-induced vascular endothelial injury. Phytomedicine 2020, 79, 153325.
  47. Lee, S.R.; Choi, E.; Jeon, S.H.; Zhi, X.Y.; Yu, J.S.; Kim, S.H.; Lee, J.; Park, K.M.; Kim, K.H. Tirucallane triterpenoids from the stems and stem bark of Cornus walteri that control adipocyte and osteoblast differentiations. Molecules 2018, 23, 2732.
  48. Desai, S.; Desai, D.G.; Kaur, H. Saponins and their biological activities. Pharma. Times 2009, 41, 13–16.
  49. Blanco-Pérez, F.; Steigerwald, H.; Schülke, S.; Vieths, S.; Toda, M.; Scheurer, S. The dietary fiber pectin: Health benefits and potential for the treatment of allergies by modulation of gut microbiota. Curr. Allergy Asthma Rep. 2021, 21, 43.
  50. Kumar, A.; Kumari, P.; Gupta, K.; Singh, M.; Tomer, V. Recent Advances in Extraction, Techno-functional Properties, Food and Therapeutic Applications as Well as Safety Aspects of Natural and Modified Stabilizers. Food Rev. Int. 2021, 1, 1–44.
  51. Sista Kameshwar, A.K.; Qin, W. Structural and functional properties of pectin and lignin–carbohydrate complexes de-esterases: A review. Bioresour. Bioprocess 2018, 5, 43.
  52. Baghaei, B.; Skrifvars, M. All-cellulose composites: A review of recent studies on structure, properties and applications. Molecules 2021, 25, 2836.
  53. Heinze, T.; El Seoud, O.A.; Koschella, A. Production and characteristics of cellulose from different sources. In Cellulose Derivatives; Springer Series on Polymer and Composite Materials; Springer: Cham, Germany, 2018; pp. 1–38.
  54. Johar, N.; Ahmad, I.; Dufresne, A. Extraction, preparation and characterization of cellulose fibres and nanocrystals from rice husk. Ind. Crops Prod. 2012, 37, 93–99.
  55. Sun, R.C. Lignin Source and Structural Characterization. ChemSusChem 2020, 13, 4385–4393.
  56. Watkins, D.; Nuruddin, M.; Hosur, M.; Tcherbi-Narteh, A.; Jeelani, S. Extraction and characterization of lignin from different biomass resources. J. Mater. Res. Technol. 2015, 4, 26–32.
  57. Vinardell, M.P.; Mitjans, M. Lignins and their derivatives with beneficial effects on human health. Int. J. Mol. Sci. 2017, 18, 1219.
  58. Dhingra, D.; Michael, M.; Rajput, H.; Patil, R.T. Dietary fibre in foods: A review. J. Food Sci. Technol. 2011, 49, 255–266.
  59. Farhat, W.; Venditti, R.; Quick, A.; Taha, M.; Mignard, N.; Becquart, F.; Ayoub, A. Hemicellulose extraction and characterization for applications in paper coatings and adhesives. Ind. Crops Prod. 2017, 107, 370–377.
  60. Bonechi, C.; Consumi, M.; Donati, A.; Leone, G.; Magnani, A.; Tamasi, G.; Rossi, C. Biomass: An overview. Bioenergy Syst. Future 2013, 18, 3–42.
  61. Ma, J.; Huo, X.Q.; Chen, X.; Zhu, W.X.; Yao, M.C.; Qiao, Y.J.; Zhang, Y.L. Study on screening potential traditional Chinese medicines against 2019-nCoV based on Mpro and PLP. Zhongguo Zhong Yao Za Zhi 2020, 45, 1219–1224.
  62. Birt, D.F.; Boylston, T.; Hendrich, S.; Jane, J.L.; Hollis, J.; Li, L.; McClelland, J.; Moore, S.; Phillips, G.J.; Rowling, M.; et al. Resistant starch: Promise for improving human health. Adv. Nutri. 2013, 4, 587–601.
  63. Fadel, A.; Ashworth, J.; Plunkett, A.; Mahmoud, A.M.; Ranneh, Y.; Li, W. Improving the extractability of arabinoxylans and the molecular weight of wheat endosperm using extrusion processing. J. Cereal Sci. 2018, 84, 55–61.
  64. Kellow, N.J.; Walker, K.Z. Authorised EU health claim for arabinoxylan. In Foods, Nutrients and Food Ingredients with Authorised EU Health Claims; Sadler, M.J., Ed.; Woodhead Publishing: Cambridge, UK, 2018; pp. 201–218.
  65. Butardo, V.M., Jr.; Sreenivasulu, N. Tailoring grain storage reserves for a healthier rice diet and its comparative status with other cereals. Int. Rev. Cell Mol. Biol. 2016, 323, 31–70.
  66. Merriam-Webster. Definition of Extracting. Available online: https://www.merriam-webster.com/dictionary/extracting (accessed on 21 June 2022).
  67. Azman, E.M.; Charalampopoulos, D.; Chatzifragkou, A. Acetic acid buffer as extraction medium for free and bound phenolics from dried blackcurrant (Ribes nigrum L.) skins. J. Food Sci. 2020, 85, 3745–3755.
  68. Gopalasatheeskumar, K.; Parthiban, S.; Manimaran, T.; Boopathi, T. Phytochemical screening on various extracts (benzene, ethanolic and aqueous) of stem parts of Zanthoxylum rhetsa (roxb.) Dc. Inter.J. Uni. Pharm. Bio Sci. 2017, 6, 79–91.
  69. Laboukhi-Khorsi, S.; Daoud, K.; Chemat, S. Efficient solvent selection approach for high solubility of active phytochemicals: Application for the extraction of an antimalarial compound from medicinal plants. ACS Sustain. Chem. Eng. 2017, 5, 4332–4339.
  70. Kim, S.K.; Wijesekara, I. Role of marine nutraceuticals in cardiovascular health. In Sustained Energy for Enhanced Human Functions and Activity; Academic Press: Cambridge, MA, USA, 2017; pp. 273–279.
  71. Altemimi, A.; Lakhssassi, N.; Baharlouei, A.; Watson, D.G.; Lightfoot, D.A. Phytochemicals: Extraction, Isolation, and Identification of Bioactive Compounds from Plant Extracts. Plants 2017, 6, 42.
  72. Banu, K.S.; Cathrine, L. General techniques involved in phytochemical analysis. Int. J. Adv. Res. Chem. Sci. 2015, 2, 25–32.
  73. Raaman, N. Phytochemical Techniques; New India Publishing Agency: Delhi, India, 2006.
  74. Cvetanović, A.; Uysal, S.; Pavlić, B.; Sinan, K.I.; Llorent-Martínez, E.J.; Zengin, G. Tamarindus indica L. seed: Optimization of maceration extraction recovery of tannins. Food Anal. Methods 2020, 13, 579–590.
  75. Okoduwa, S.I.R.; Umar, I.A.; James, D.B.; Inuwa, H.M.; Habila, J.D. Evaluation of extraction protocols for anti-diabetic phytochemical substances from medicinal plants. World J. Diabetes 2016, 7, 605.
  76. Ćujić, N.; Šavikin, K.; Janković, T.; Pljevljakušić, D.; Zdunić, G.; Ibrić, S. Optimization of polyphenols extraction from dried chokeberry using maceration as traditional technique. Food Chem. 2016, 194, 135–142.
  77. Kannaian, U.P.N.; Edwin, J.B.; Rajagopal, V.; Shankar, S.N.; Srinivasan, B. Phytochemical composition and antioxidant activity of coconut cotyledon. Heliyon 2020, 6, e03411.
  78. Kalia, V.C.; Lal, S.; Rashmi. Modified cold percolation method for extracting oil from oil seeds. J. Sci. Ind. Res. 2002, 61, 630–634.
  79. Ennaifer, M.; Bouzaiene, T.; Chouaibi, M.; Hamdi, M. Pelargonium graveolens aqueous decoction: A new water-soluble polysaccharide and antioxidant-rich extract. BioMed. Res. Int. 2018, 2018, e2691513.
  80. Khajehei, F.; Niakousari, M.; Seidi Damyeh, M.; Merkt, N.; Claupein, W.; Graeff-Hoenninger, S. Impact of ohmic-assisted decoction on bioactive components extracted from yacon (Smallanthus sonchifolius poepp.) leaves: Comparison with conventional decoction. Molecules. 2017, 22, 2043.
  81. Shang, Y.F.; Zhang, T.H.; Thakur, K.; Zhang, J.G.; CESPEDES-ACUÑA, C.L.A.; Wei, Z.J. HPLC-MS/MS targeting analysis of phenolics metabolism and antioxidant activity of extractions from Lycium barbarum and its meal using different methods. Food Sci. Technol. 2022, 42, e71022.
  82. Chua, L.S.; Latiff, N.A.; Mohamad, M. Reflux extraction and cleanup process by column chromatography for high yield of andrographolide enriched extract. J. Appl. Res. Med. Aromat. Plants 2016, 3, 64–70.
  83. Larsen, B.S.; Kaiser, M.A.; Botelho, M.; Wooler, G.R.; Buxton, L.W. Comparison of pressurized solvent and reflux extraction methods for the determination of perfluorooctanoic acid in polytetrafluoroethylene polymers using LC-MS-MS. Analyst 2005, 130, 59–62.
  84. Sulaiman, M.; Zhigila, D.A.; Mohammed, K.; Umar, D.M.; Aliyu, B.; Manan, F.A. Moringa oleifera seed as alternative natural coagulant for potential application in water treatment: A review. J. Adv. Rev. Sci. Res. 2017, 30, 1–11.
  85. Mohammad Azmin, S.N.H.; Abdul Manan, Z.; Wan Alwi, S.R.; Chua, L.S.; Mustaffa, A.A.; Yunus, N.A. Herbal processing and extraction technologies. Sep. Puri. Rev. 2016, 45, 305–320.
  86. Duarte, K.; Justino, C.I.L.; Gomes, A.M.; Rocha-Santos, T.; Duarte, A.C. Green analytical methodologies for preparation of extracts and analysis of bioactive compounds. Compr. Anal. Chem. 2014, 65, 59–78.
  87. Mustafa, A.; Trevino, L.M.; Turner, C. Pressurized hot ethanol extraction of carotenoids from carrot by-products. Molecules 2012, 17, 1809–1818.
  88. Vilaplana, F.; Karlsson, P.; Ribes-Greus, A.; Ivarsson, P.; Karlsson, S. Analysis of brominated flame retardants in styrenic polymers: Comparison of the extraction efficiency of ultrasonication, microwave-assisted extraction and pressurized liquid extraction. J. Chromatogr. A 2008, 1196, 139–146.
  89. Suhitha, S.; Devi, S.K.; Gunasekaran, K.; Carehome Pakyntein, H.; Bhattacharjee, A.; Velmurugan, D. Phytochemical analyses and activity of herbal medicinal plants of North-East India for anti-diabetic, anti-cancer and anti-tuberculosis and their docking studies. Curr. Top. Med. Chem. 2015, 15, 21–36.
  90. Yousuf, O.; Gaibimei, P.; Singh, A. Ultrasound assisted extraction of oil from soybean. Int. J. Curr. Microbiol. Appl. Sci. 2018, 7, 843–852.
  91. Medina-Torres, N.; Ayora-Talavera, T.; Espinosa-Andrews, H.; Sánchez-Contreras, A.; Pacheco, N. Ultrasound assisted extraction for the recovery of phenolic compounds from vegetable sources. Agronomy 2017, 7, 47.
  92. Ranjha, M.M.A.N.; Kanwal, R.; Shafique, B.; Arshad, R.N.; Irfan, S.; Kieliszek, M.; Kowalczewski, P.L.; Irfan, M.; Khalid, M.Z.; Roobab, U.; et al. A critical review on pulsed electric field: A novel technology for the extraction of phytoconstituents. Molecules 2021, 26, 4893.
  93. Lakka, A.; Bozinou, E.; Makris, D.P.; Lalas, S.I. Evaluation of pulsed electric field polyphenol extraction from Vitis vinifera, Sideritis scardica and Crocus sativus. ChemEngineering 2021, 5, 25.
  94. Martínez, J.M.; Schottroff, F.; Haas, K.; Fauster, T.; Sajfrtová, M.; Álvarez, I.; Raso, J.; Jaeger, H. Evaluation of pulsed electric fields technology for the improvement of subsequent carotenoid extraction from dried Rhodotorula glutinis yeast. Food Chem. 2020, 323, 126824.
  95. Pontillo, A.R.N.; Papakosta-Tsigkri, L.; Lymperopoulou, T.; Mamma, D.; Kekos, D.; Detsi, A. Conventional and enzyme-assisted extraction of rosemary leaves (Rosmarinus officinalis L.): Toward a greener approach to high added-value extracts. Appl. Sci. 2021, 11, 3724.
  96. Heemann, A.C.W.; Heemann, R.; Kalegari, P.; Spier, M.R.; Santin, E. Enzyme-assisted extraction of polyphenols from green yerba mate. Braz. J. Food Technol. 2019, 22, 1–10.
  97. Ahangari, H.; King, J.W.; Ehsani, A.; Yousefi, M. Supercritical fluid extraction of seed oils—A short review of current trends. Trends Food Sci. Technol. 2021, 111, 249–260.
  98. Volcho, K.P.; Anikeev, V.I. Environmentally benign transformations of monoterpenes and monoterpenoids in supercritical fluids. In Supercritical Fluid Technology for Energy and Environmental Applications; Anikeev, V.I., Fan, M., Eds.; Elsevier: Amsterdam, The Netherlands, 2014; pp. 69–87.
  99. Jamaludin, R.; Kim, D.S.; Md Salleh, L.; Lim, S.B. Optimization of high hydrostatic pressure extraction of bioactive compounds from noni fruits. J. Food Meas. Charac. 2020, 14, 2810–2818.
  100. Moreira, S.A.; Silva, S.; Costa, E.; Pinto, S.; Sarmento, B.; Saraiva, J.A. and Pintado, M.; Effect of high hydrostatic pressure extraction on biological activities and phenolics composition of winter savory leaf extracts. Antioxidants 2020, 9, 841.
  101. Scepankova, H.; Martins, M.; Estevinho, L.; Delgadillo, I.; Saraiva, J.A. Enhancement of bioactivity of natural extracts by non-thermal high hydrostatic pressure extraction. Plant Foods Hum. Nut. 2018, 73, 253–267.
  102. Bier, M.C.J.; Medeiros, A.B.P.; de Oliveira, J.S.; Côcco, L.C.; da Luz Costa, J.; de Carvalho, J.C.; Soccol, C.R. Liquefied gas extraction: A new method for the recovery of terpenoids from agroindustrial and forest wastes. J. Super. Fluids 2016, 110, 97–102.
  103. Ivanović, M.; Islamčević Razboršek, M.; Kolar, M. Innovative extraction techniques using deep eutectic solvents and analytical methods for the isolation and characterization of natural bioactive compounds from plant material. Plants 2020, 9, 1428.
  104. Mulia, K.; Putri, S.; Krisanti, E.; Nasruddin. Natural deep eutectic solvents (NADES) as green solvents for carbon dioxide capture. AIP Conf. Proc. 2017, 1923, 020022.
  105. Paiva, A.; Craveiro, R.; Aroso, I.; Martins, M.; Reis, R.L.; Duarte, A.R.C. Natural deep eutectic solvents—Solvents for the 21st century. ACS Sustain. Chem. Eng. 2014, 2, 1063–1071.
  106. Yaqoob, M.; Aggarwal, P.; Babbar, N. Extraction and screening of kinnow (Citrus reticulata L.) peel phytochemicals, grown in Punjab, India. Biomass Convers. Biorefin. 2022, 1, 1–13.
  107. Mihalcea, L.; Turturică, M.; Cucolea, E.I.; Dănilă, G.M.; Dumitrașcu, L.; Coman, G.; Constantin, O.E.; Grigore-Gurgu, L.; Stănciuc, N. CO2 supercritical fluid extraction of oleoresins from Sea buckthorn pomace: Evidence of advanced bioactive profile and selected functionality. Antioxidants 2021, 10, 1681.
  108. Ordóñez-Santos, L.E.; Esparza-Estrada, J.; Vanegas-Mahecha, P. Ultrasound-assisted extraction of total carotenoids from mandarin epicarp and application as natural colorant in bakery products. LWT-Food Sci. Tech. 2021, 139, 110598.
  109. Purnomo, T.A.B.; Kurniawan, Y.S.; Kesuma, R.F.; Yuliati, L. Selection of maceration solvent for natural pigment extraction from red fruit (Pandanus conoideus Lam). Indones. J. Nat. Pigment. 2020, 2, 8.
  110. Li, H.; Zhao, C.; Tian, H.; Yang, Y.; Li, W. Liquid–liquid microextraction based on acid–base-induced deep eutectic solvents for determination of β-carotene and lycopene in fruit juices. Food Anal. Methods 2019, 12, 2777–2784.
  111. Martínez, J.M.; Delso, C.; Angulo, J.; Álvarez, I.; Raso, J. Pulsed electric field-assisted extraction of carotenoids from fresh biomass of Rhodotorula glutinis. Innov. Food Sci. Emerg. Technol. 2018, 47, 421–427.
  112. Pavlić, B.; Mrkonjić, Ž.; Teslić, N.; Kljakić, A.C.; Pojić, M.; Mandić, A.; Stupar, A.; Santos, S.; Duarte, A.R.C.; Mišan, A. Natural deep eutectic solvent (NADES) extraction improves polyphenol yield and antioxidant activity of wild thyme (Thymus serpyllum L.) extracts. Molecules 2022, 27, 1508.
  113. Popovic, B.M.; Micic, N.; Potkonjak, A.; Blagojevic, B.; Pavlovic, K.; Milanov, D.; Juric, T. Novel extraction of polyphenols from sour cherry pomace using natural deep eutectic solvents—Ultrafast microwave-assisted NADES preparation and extraction. Food Chem. 2022, 366, 130562.
  114. Frohlich, P.C.; Santos, K.A.; Hasan, S.D.M.; da Silva, E.A. Evaluation of the ethanolic ultrasound-assisted extraction from clove (Syzygium aromaticum) leaves and chemical characterization of the extracts. Food Chem. 2022, 373, 131351.
  115. Domínguez-Rodríguez, G.; Marina, M.L.; Plaza, M. Enzyme-assisted extraction of bioactive non-extractable polyphenols from sweet cherry (Prunus avium L.) pomace. Food Chem. 2021, 339, 128086.
  116. Hwang, H.J.; Kim, H.J.; Ko, M.J.; Chung, M.S. Recovery of hesperidin and narirutin from waste Citrus unshiu peel using subcritical water extraction aided by pulsed electric field treatment. Food Sci. Biotechnol. 2021, 30, 217–226.
  117. Velásquez, P.; Bustos, D.; Montenegro, G.; Giordano, A. Ultrasound-Assisted Extraction of Anthocyanins Using Natural Deep Eutectic Solvents and Their Incorporation in Edible Films. Molecules 2021, 26, 984.
  118. Grdiša, M.; Varga, F.; Ninčević, T.; Ptiček, B.; Dabić, D.; Biošić, M. The extraction efficiency of maceration, UAE and MSPD in the extraction of pyrethrins from Dalmatian pyrethrum. Agric. Conspec. Sci. 2020, 85, 257–267.
  119. Sharma, B.R.; Kumar, V.; Kumar, S.; Panesar, P.S. Microwave assisted extraction of phytochemicals from Ficus racemosa. Curr. Res. Green Sustain. Chem. 2020, 3, 100020.
  120. Oroian, M.; Ursachi, F.; Dranca, F. Ultrasound-assisted extraction of polyphenols from crude pollen. Antioxidants 2020, 9, 322.
  121. de Queiroz, J.E.; dos Santos, D.M.; Vila Verde, G.M.; de Paula, J.R.; de Aquino, G.L.B. Microwave irradiation to the rapid extraction of Stryphnodendron adstringens (Barbatimão) compounds by statistical planning. Nat. Prod. Res. 2019, 35, 354–358.
  122. Thomas, J.; Barley, A.; Willis, S.; Thomas, J.; Verghese, M.; Boateng, J. Effect of Different Solvents on the Extraction of Phytochemicals in Colored Potatoes. Food Nut. Sci. 2020, 11, 942.
  123. Shikov, A.N.; Kosman, V.M.; Flissyuk, E.V.; Smekhova, I.E.; Elameen, A.; Pozharitskaya, O.N. Natural deep eutectic solvents for the extraction of phenyletanes and phenylpropanoids of Rhodiola rosea L. Molecules 2020, 25, 1826.
  124. de Mello, B.T.F.; Iwassa, I.J.; Cuco, R.P.; dos Santos Garcia, V.A.; da Silva, C. Methyl acetate as solvent in pressurized liquid extraction of crambe seed oil. J. Super. Fluids. 2019, 145, 66–73.
  125. Castro-López, C.; Ventura-Sobrevilla, J.M.; González-Hernández, M.D.; Rojas, R.; Ascacio-Valdés, J.A.; Aguilar, C.N.; Martínez-Ávila, G.C.G. Impact of extraction techniques on antioxidant capacities and phytochemical composition of polyphenol-rich extracts. Food Chem. 2017, 237, 1139–1148.
  126. Jovanović, A.A.; Đorđević, V.B.; Zdunić, G.M.; Pljevljakušić, D.S.; Šavikin, K.P.; Gođevac, D.M.; Bugarski, B.M. Optimization of the extraction process of polyphenols from Thymus serpyllum L. herb using maceration, heat- and ultrasound-assisted techniques. Sep. Purif. Technol. 2017, 179, 369–380.
  127. Da Porto, C.; Natolino, A. Supercritical fluid extraction of polyphenols from grape seed (Vitis vinifera): Study on process variables and kinetics. J. Supercrit. Fluid. 2017, 130, 239–245.
  128. Obluchinskaya, E.D.; Daurtseva, A.V.; Pozharitskaya, O.N.; Flisyuk, E.V.; Shikov, A.N. Natural Deep Eutectic Solvents as Alternatives for Extracting Phlorotannins from Brown Algae. Pharma. Chem. J. 2019, 53, 243–247.
  129. Sharif, M.F.; Bennett, M.T. The effect of different methods and solvents on the extraction of polyphenols in ginger (Zingiber officinale). J. Teknol. 2016, 78, 49–54.
  130. de Aquino, D.S.; Roders, C.; Vessoni, A.M.; Stevanato, N.; Da Silva, C. Assessment of obtaining sunflower oil from enzymatic aqueous extraction using protease enzymes. Grasas Aceites 2022, 73, e452.
  131. Hien, T.T.; Minh, N.T. Enhancing the extraction of pumpkin seed (Cucurbita pepo L) for increasing oil yield and its phytosterol content. Food Sci. Appl. Biotechnol. 2021, 4, 6.
  132. Jalani, N.F. Extraction and purification of phytosterols mixture from palm fatty acid distillate (PFAD) using multistage extraction processes. J. Oil Palm. Res. 2020, 33, 93–102.
  133. Jafarian Asl, P.; Niazmand, R.; Yahyavi, F. Extraction of phytosterols and tocopherols from rapeseed oil waste by supercritical CO2 plus co-solvent: A comparison with conventional solvent extraction. Heliyon 2020, 6, e03592.
  134. Ibrahim, N.H.; Mahmud, M.S.; Nurdin, S. Microwave-assisted extraction of β-sitosterol from cocoa shell waste. IOP Conf. Ser. Mater. Sci. Eng. 2020, 991, 012106.
  135. Li, H.; Zhai, B.; Sun, J.; Fan, Y.; Zou, J.; Cheng, J.; Zhang, X.; Shi, Y.; Guo, D. Ultrasound-assisted extraction of total saponins from Aralia taibaiensis: Process optimization, phytochemical characterization, and mechanism of α-glucosidase inhibition. Drug Des. Devel. Ther. 2022, 16, 83–105.
  136. Liu, R.; Chu, X.; Su, J.; Fu, X.; Kan, Q.; Wang, X.; Zhang, X. Enzyme-assisted ultrasonic extraction of total flavonoids from Acanthopanax senticosus and their enrichment and antioxidant properties. Processes 2021, 9, 1708.
  137. Yang, G.Y.; Song, J.N.; Chang, Y.Q.; Wang, L.; Zheng, Y.G.; Zhang, D.; Guo, L. Natural deep eutectic solvents for the extraction of bioactive steroidal saponins from Dioscoreae nipponicae rhizoma. Molecules 2021, 26, 2079.
  138. Ramli, N.H.; Yusup, S.; Quitain, A.T.; Johari, K.; Kueh, B.W.B. Optimization of saponin extracts using microwave-assisted extraction as a sustainable biopesticide to reduce Pomacea canaliculata population in paddy cultivation. Sustain. Chem. Pharm. 2019, 11, 23–35.
  139. Lanjekar, K.J.; Rathod, V.K. Green extraction of glycyrrhizic acid from Glycyrrhiza glabra using choline chloride based natural deep eutectic solvents (NADESs). Process Biochem. 2021, 102, 22–32.
  140. Shikov, A.N.; Shikova, V.A.; Whaley, A.O.; Burakova, M.A.; Flisyuk, E.V.; Whaley, A.K.; Terninko, I.I.; Generalova, Y.E.; Gravel, I.V.; Pozharitskaya, O.N. The Ability of Acid-Based Natural Deep Eutectic Solvents to Co-Extract Elements from the Roots of Glycyrrhiza glabra L. and Associated Health Risks. Molecules 2022, 27, 7690.
  141. Rodrigues, V.H.; de Melo, M.M.R.; Portugal, I.; Silva, C.M. Extraction of added-value triterpenoids from Acacia dealbata leaves using supercritical fluid extraction. Processes 2021, 9, 1159.
  142. Gong, T.; Liu, S.; Wang, H.; Zhang, M. Supercritical CO2 fluid extraction, physicochemical properties, antioxidant activities and hypoglycemic activity of polysaccharides derived from fallen Ginkgo leaves. Food Biosci. 2021, 42, 101153.
  143. García, P.; Fredes, C.; Cea, I.; Lozano-Sánchez, J.; Leyva-Jiménez, F.J.; Robert, P.; Vergara, C.; Jimenez, P. Recovery of Bioactive Compounds from Pomegranate (Punica granatum L.) Peel Using Pressurized Liquid Extraction. Foods 2021, 10, 203.
  144. Hussain, S.; Sharma, M.; Bhat, R. Valorisation of sea buckthorn pomace by optimization of ultrasonic-assisted extraction of soluble dietary fibre using response surface methodology. Foods 2021, 10, 1330.
  145. Rivas, M.Á.; Casquete, R.; de Guía Córdoba, M.; Benito, M.J.; Hernández, A.; Ruiz-Moyano, S.; Martín, A. Functional properties of extracts and residual dietary fibre from pomegranate (Punica granatum L.) peel obtained with different supercritical fluid conditions. LWT-Food Sc. Tech. 2021, 145, 111305.
  146. Douard, L.; Bras, J.; Encinas, T.; Belgacem, M.N. Natural acidic deep eutectic solvent to obtain cellulose nanocrystals using the design of experience approach. Carbohydr. Polym. 2021, 252, 117136.
  147. Gan, J.; Huang, Z.; Yu, Q.; Peng, G.; Chen, Y.; Xie, J.; Nie, S.; Xie, M. Microwave assisted extraction with three modifications on structural and functional properties of soluble dietary fibers from grapefruit peel. Food Hydrocoll. 2020, 101, 105549.
  148. Cheikh Rouhou, M.; Abdelmoumen, S.; Thomas, S.; Attia, H.; Ghorbel, D. Use of green chemistry methods in the extraction of dietary fibers from cactus rackets (Opuntia ficus indica): Structural and microstructural studies. Int. J. Biol. Macromol. 2018, 116, 901–910.
More
© Text is available under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Video Production Service
Feedback