Ultrasound-Assisted “Green” Extraction (UAE) of Antioxidant Compounds (Betalains and Phenolics) from Opuntia stricta var. Dilenii’s Fruits: Optimization and Biological Activities

Abstract

Opuntia stricta var. Dillenii’s prickly pears are an underutilized fruit with a high content of betalains and phenolic compounds that could bring potential health benefits for humans. The aim of this study is the optimization of the “green” extraction of betalains and phenolic compounds from Opuntia stricta var. Dillenii’s whole fruits by ultrasound-assisted extraction (UAE), using a response surface methodology (RSM) by a central composite design (CCD) in order to obtain extracts rich in betalains and phenolic compounds with proven biological activities. For UAE optimization, the extraction temperature (20–50 °C), the amplitude (20–50%) and the ethanol volume in extraction solvent (15–80%, v/v) were selected as independent variables. All combinations were conducted at 2, 5, 10, 20 and 30 min to determinate the time effect. The betalain and phenolic compound content in Opuntia stricta var. Dillenii’s whole fruits and UAE extracts were identified by HPLC-DAD-ESI/MS and HPLC-DAD-MS/QTOF and the antioxidant (ORAC method) and the anti-inflammatory (hyaluronidase inhibition method) in vitro biological activities also were determined. The most efficient extraction time was 5 min and the best UAE parameter combination was 50% amplitude, 15% ethanol in solvent (ethanol/water, 15/85, v/v) and 20 °C temperature, obtaining 10.06 ± 0.10 mg of total major betalains/g dry weight, 2.32 ± 0.08 mg of piscidic acid/g dry weight and 0.38 ± 0.00 mg of total major flavonoids/g dry weight. All applied UAE combinations significantly improved the in vitro bioactive activities (antioxidant and anti-inflammatory) of the Opuntia stricta var. Dillenii’s extracts compared to the bioactivities of the extracts obtained by standard homogenization processes.

Betalain-Enriched Beetroots Exhibit Antiulcer and Anti-inflammatory Potentials

“…Additionally, it has been shown that betalains have the capacity to inhibit the enzymes lipoxygenase and cyclooxygenase-2 [51]. This finding was in accordance with the previous reports that shown betalains can also inhibit the hyaluronidase enzyme [60][61][62][63]. Another investigation showed that two of the compounds of our dye as betanidin (7%) and betanin (43%) were able to inhibit key enzymes related to gastric inflammation as COX by interaction with Tyr-385 and Ser-530 residues close to the active site of COX [64,65].…”

Application of ultrasound technology for extraction of color pigments from plant sources and their potential bio‐functional properties: A review

“…However, the UAE exhibited betacyanin (4.87 mg/g) and betaxanthin (2.64 mg/g) in red beets after 30 min extraction time at the solvent/sample ratio of 75 ml/g (Silva et al, 2020). Betalain content of 10.05 mg/g was obtained from Opuntia Dillenii whole fruit by ultrasonication treatment at 15% of ethanol and 20°C of temperature (Gómez‐López et al, 2021). The higher betacyanin content was found from ultrasound extraction (71.34 mg/100 g and 82.79 mg/100 g) as compared to Soxhlet extraction (17.64 mg/100 g and 18.67 mg/100 g) of peel and flesh of red dragon fruit, respectively (Ramli et al, 2014).…”

“…Consumption of β‐carotene, β‐cryptoxanthin, lutein, and zeaxanthin decreases the risk of developing prostate cancer by 15%. According to a meta‐analysis, the effects of carotenoids, lycopene, and β‐carotene are linked to a 30% reduction in the development of lung cancer (Gómez‐López et al, 2021). Among all, β‐carotene is the most ubiquitous and is present in abundance in several fruits and leafy vegetables.…”

Impact of different solvents on extraction yield, phenolic composition, in vitro antioxidant and antibacterial activities of deseeded Opuntia stricta fruit

“…Moreover, O. stricta extracts obtained from flowers and whole fruits or peels exhibited many pharmacological activities such as anti-spermatogenic, hypotensive, anti-oxidant, antibacterial, anti-inflammatory, antiviral, analgesic and anticancer [8][9][10][11][12][13][14][15][16]. These beneficial medicinal features are as a result of their chemical contents of antioxidants, pigments, and phenolic acids [17,18].…”