Table 3.
Summary of some of the optimal or suggested conditions for the extraction of betalains by non-conventional extraction methods from natural sources.
| Extraction method | Sample | Compound(s) | RL/S | Solvent | Solvents ratio (%) | Temperature | Time | Other condition | Reference |
|---|---|---|---|---|---|---|---|---|---|
| Enzimatic treatment | Hylocereus polyrhizus fruit | betanin, isobetanin, phylocactin, hylocerenin, isophyllocactin, and isohylocerenin | 1 mL/g | water (acidified with citric acid, pH 4) | 100 | 40 °C | 120 min | stirring speed of 250 rpm | Naderi et al., 2010 |
| Ultrasound-assisted | Colored quinoa (Chenopodium quinoa Willd) hulls | betacyanins | 100 mL/g | water | 100 | 9.2 s | power of 100 W, 30 kHz, 70% of amplitude, pulse of 0.6 | Laqui-Vilca et al., 2018 | |
| betaxanthins | 100 mL/g | water | 100 | 40 s | power of 100 W, 30 kHz, 90% of amplitude, pulse of 0.7 | Laqui-Vilca et al., 2018 | |||
| Grown red and golden beets (Beta vulgaris L.) | betacyanins and betaxanthins | 2 mL/g | methanol | 100 | 60 min | Wang et al., 2020 | |||
| Red beet (Beta vulgaris L.) | betacyanins and betaxanthins | 5 mL/g | ethanol:water (acidified with acetic acid, 0.5%) | 30:70–45:55 | 55 °C | 15 min | 37 kHz. After sonication, stirring at 320 rpm for 43 min at 40 °C | Haq et al., 2020 | |
| betacyanins and betaxanthins | 75 mL/g | water | 100 | 30 °C | 30 min | power of 83 W | Silva et al., 2020 | ||
| betacyanins | 25 mL/g | ethanol:water | 25:75 | 52 °C | 90 min | power of 165 W, 25 kHz | da Silva et al., 2018 | ||
| betaxanthins | 25 mL/g | ethanol:water | 25:75 | 37 °C | 90 min | power of 165 W, 25 kHz | da Silva et al., 2018 | ||
| betacyanins and betaxanthins | 15 mL/g | water (pH 2.5) | 50 °C | 10 min | Kushwaha et al., 2018 | ||||
| betacyanins and betaxanthins | 19 mL/g | water | 100 | 53 °C | 35 min | power of 89 W | Maran & Priya, 2016 | ||
| Red dragon fruit (Hylocereus polyrhizus) flesh | betacyanin | 25 mL/g | water | 100 | 25 °C | 30 min | 50 kHz | Ramli et al., 2014 | |
| Red pitaya (Stenocereus stellatus) | betacyanins and betaxanthins | ≈2 mL/g | water | 100 | 20 °C | 15 min | 40 kHz. After sonication, stirring at 3200 rpm | Pérez-Loredo et al., 2017 | |
| Opuntia engelmannii fruit peel | betacyanins | 200 mL/g | methanol:water (pH 7) | 17:83 | 33.9 °C | 1.2 min | 40 kHz, stirring speed of 200 rpm | Melgar et al., 2019 | |
| β-CD-enhanced ultrasound assisted | Red beets (Beta vulgaris L) | betanin | 10 mL/g | water:β-Ciclodextrin (β-CD) | 95:5 | 30 min | 28 kHz, 80 W. Prior to ultrasound treatment, the sample solution was homogenized for 180 min. | Tutunchi et al., 2019 | |
| Microwave assissted | Dragon fruit (Hylocereus polyzhirus) peel | betalains | 25 mL/g | water | 100 | 35°C | 8 min | microwave power of 100 W | Thirugnanasambandham & Sivakumar, 2015 |
| Red beetroot (Beta vulgaris L.) | betacyanins (betanin) | 250 mL/g | ethanol:water (acidified with ascorbic acid, 0.04 mol/L) | 50:50 | 1.17 min/1.7 min | microwave power of 400 W; duty cycle of 100% | Cardoso-Ugarte et al., 2014 | ||
| betaxanthins | 250 mL/g | ethanol:water (acidified with ascorbic acid, 0.04 mol/L) | 50:50 | 2.7 min/1.8 min | microwave power of 400 W; duty cycle of 100% | (Cardoso-Ugarte et al., 2014 | |||
| Red beetroot (Beta vulgaris L.) peel | betacyanins (betanin) | 5 mL/g | water (acidified with citric acid, pH 5.2) | 100 | 0.95 min | microwave power of 224.61 W | Singh et al., 2017 | ||
| betacyanins (betanin) | 5 mL/g | ethanol | 100 | 1.25 min | microwave power of 384.25 W | Singh et al., 2017 | |||
| betacyanins and betaxanthins | (4:1, 2:1, 2:1, and 1.5:1) | water | 100 | 12 min (4 times of 3 min) | microwave power of 450 W | Slavov et al., 2013 | |||
| Opuntia engelmannii fruit peel | betacyanins | 49 mL/g | methanol:water (pH 7) | 55:45 | 25°C | 8.8 min | microwave power of 400 W | Melgar et al., 2019 | |
| White-fleshed red pitaya (Hylocereus undatus) | betacyanins | 150 mL/g | water | 100 | 49.33°C | 5 min | microwave power of 600 W | Ferreres et al., 2017 | |
| Yellow pitaya (Hylocereus megalanthus) | betacyanins | 150 mL/g | water | 100 | 49.33°C | 5 min | microwave power of 600 W | Ferreres et al., 2017 | |
| Pulsed electric field | Red beet (Beta vulgaris L.) | betanin and vulgaxanthin | 100 mL/g | phosphate buffer, pH 6.5 | 100 | 20 μs pulses of electric field at 4.38 kV cm−1 of strength, Energy of 4.86 kJ/kg. | Nowacka et al., 2019 | ||
| betalains | 20 mL/g | water | 100 | 100 μs pulses with electric field strengthat 1 kV cm−1 of strength. | Loginova et al., 2011 | ||||
| High-Pulsed Electric Fields (HPEF) | Prickly Pear (Opuntia spp.) fruits | betacyanins and betaxanthins | 10 min | 8 kV cm−1, repetition rate of 5 Hz. | Jiménez-Alvarado et al., 2015 | ||||
| High Pressure Carbon Dioxide (HPCD) | Cactus pears (Opuntia spp.) fruit | betacyanins and betaxanthins | sample + water (acidified with citric acid, pH 5):CO2 pressurized | 20:80 | 40°C | 30 min | high pressure CO2 pre-treatment of dried sample pre-heated to 55°C, CO2 at 375 bar for 60 min | Nunes et al., 2015 | |
| Supercritical Fluid Extraction (SFE) | Hylocereus polyrhizus flesh and peel | betacyanins | co-solvent (ethanol:water 10:90):CO2 pressurized | 90:10 | 50°C | 90 min | pressure of 25 Mpa | Fathordoobady et al., 2016 |
RL/S mean: Ratio liquid (solvent)/solid.