scholarly journals Optimization of Oleuropein and Luteolin-7-O-Glucoside Extraction from Olive Leaves by Ultrasound-Assisted Technology

Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2486 ◽  
Author(s):  
Antonio Lama-Muñoz ◽  
María del Mar Contreras ◽  
Francisco Espínola ◽  
Manuel Moya ◽  
Inmaculada Romero ◽  
...  
Keyword(s):  
Large Scale ◽  
Soxhlet Extraction ◽  
Operating Conditions ◽  
Antioxidant Compounds ◽  
Olive Leaves ◽  
Ultrasound Assisted Extraction ◽  
Mediterranean Countries ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
High Concentrations

The olive orchard cultivation in Mediterranean countries results in huge amounts of lignocellulosic biomass residues. One of the main residues are olive leaves. Olive leaves contain high concentrations of bioactive antioxidant compounds like oleuropein and luteolin-7-glucoside. The production of biactive compounds from olive leaves requires treatments capable of breaking the lignocellulosic structure. Current research focuses on use of inexpensive, quick, and not harmful to the environment treatments, searching a more simplified large-scale operation approach. Recently, advances in applied chemistry have led to possible new emerging industrial techniques like ultrasound-assisted extraction (UAE). This technology is a promising candidate as a green treatment solution for olive leaves utilization in a biorefinery. However, this application goes through prior optimization of technique and operating conditions. The goal of this study was to optimize the extraction of oleuropein and luteolin-7-glucoside from olive leaves through an investigation of the influence of key factors of ultrasound-assisted extraction using an experimental central composite design, in comparison with conventional Soxhlet extraction. The highest extraction efficiency and antioxidant capacity were obtained under optimal increment of temperature and amplitude conditions (40 °C and 30%, respectively). Values for oleuropein, luteolin-7-glucoside were 69.91 g/kg and 1.82 g/kg, respectively.

scholarly journals Ultrasound-Assisted Extraction as a First Step in a Biorefinery Strategy for Valorisation of Extracted Olive Pomace

Energies ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2679 ◽  
Author(s):  
José Carlos Martínez-Patiño ◽  
Irene Gómez-Cruz ◽  
Inmaculada Romero ◽  
Beatriz Gullón ◽  
Encarnación Ruiz ◽  
...  
Keyword(s):  
Ethanol Concentration ◽  
Total Phenolic ◽  
Natural Food ◽  
Antioxidant Compounds ◽  
Olive Pomace ◽  
Ultrasound Assisted Extraction ◽  
Antioxidant Power ◽  
Mediterranean Countries ◽  
Assisted Extraction ◽  
Ultrasound Assisted

Currently, interest in finding new feedstock as sources of natural food antioxidants is growing. The extracted olive pomace (EOP), which is an agro-industrial residue from the olive pomace extracting industries, is generated yearly in big amounts, mainly in the Mediterranean countries. EOP was subjected to an ultrasound assisted extraction with ethanol-water mixtures. The effect of main parameters, such as ethanol concentration (30–70% v/v), ultrasound amplitude (20–80%), and extraction time (5–15 min), on the extraction of antioxidant compounds was evaluated according to a Box–Behnken experimental design. The antioxidant capacity of the resulting extracts was determined by measuring their content in total phenolic compounds (TPC) and flavonoids (TFC), as well as their antioxidant activity by DPPH, ferric reducing antioxidant power (FRAP), and ABTS assays. Considering the simultaneous maximization of these five responses, the optimal conditions were found to be 43.2% ethanol concentration, 70% amplitude, and 15 min. The ultrasound assisted extraction of EOP under these optimized conditions yielded an extract with a phenolic and flavonoid content (per gram of EOP) of 57.5 mg gallic acid equivalent (GAE) and 126.9 mg rutin equivalent (RE), respectively. Likewise, the values for DPPH, ABTS, and FRAP assay (per gram of EOP) of 56.7, 139.1, and 64.9 mg Trolox equivalent, respectively were determined in the optimized extract.

scholarly journals Natural antioxidants isolated from Schinus areira leaves by ultrasound-assisted extraction

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Liliana S. Celaya ◽  
Carmen I. Viturro ◽  
Luís R. Silva ◽  
Silvia Moreno
Keyword(s):  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Natural Antioxidants ◽  
Antioxidant Compounds ◽  
Ultrasound Assisted Extraction ◽  
Leaf Extracts ◽  
Chromatography Analysis ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
Optimized Conditions

The aim of this study was to optimize the extraction of antioxidant compounds from Schinus areira leaves using  ultrasound assisted extraction and response surface methodology. The effect of sonication time and plant material:solvent ratio were used to optimize the recovery. Results showed that a high recovery of antioxidant compounds from leaves of three different S. areira specimens was achieved under optimized conditions. The leaf extracts obtained displayed a DPPH (1,1-Diphenyl-2-picrylhydrazyl) radical scavenging activity analogous to the well-known antioxidant trolox  (EC50 = 23-46 vs 36.1 µg/mL, respectively). In addition, these extracts showed a good potency to eliminate superoxide and nitric oxide-radicals as well as a moderate antimicrobial activity against gram positive Staphylococcus aureus and Enterococcus faecalis and yeast. HPLC chromatography analysis of the three S. areira leaf extracts showed different high contents of kaempferol-3-O-rutinoside, quercetin-3-O-galactoside and 3-O-caffeoylquinic acid. The results showed that the S. areira leaf extracts contained a high amount of antioxidant phenolic compounds, which might be a valuable source to be used as additives in plant-based foods.

scholarly journals Optimization of Ultrasound-Assisted Extraction of Flavonoids from Olive (Olea europaea) Leaves, and Evaluation of Their Antioxidant and Anticancer Activities

Molecules ◽  
2018 ◽  
Vol 23 (10) ◽  
pp. 2513 ◽  
Author(s):  
Bixia Wang ◽  
Jipeng Qu ◽  
Siyuan Luo ◽  
Shiling Feng ◽  
Tian Li ◽  
...  
Keyword(s):  
Olea Europaea ◽  
Maximum Yield ◽  
Flavonoid Compound ◽  
Anticancer Activities ◽  
Olive Leaves ◽  
Ultrasound Assisted Extraction ◽  
Assisted Extraction ◽  
Significant Difference ◽  
Ultrasound Assisted ◽  
Olea Europaéa

Olea europaea leaves are the major byproduct of olive farming. In this study, ultrasound-assisted extraction of flavonoids from olive leaves was optimized using response surface methodology, and the flavonoid compounds and their antioxidant and anticancer activities were investigated by high performance liquid chromatography. The results showed that the optimized conditions for achieving the maximum yield of flavonoids (74.95 mg RE/g dm) were 50 °C temperature, 270 W power, 50 min time, and 41 mL/g liquid-solid ratio. There was a significant difference in the total flavonoid content between the aged and young leaves harvested in April and July, and six main components were quantified. Among them, luteolin-4’-O-glucoside was the most predominant flavonoid compound, followed by apigenin-7-O-glucoside and rutin. Olive leaves also contained small amounts of luteolin, apigenin, and quercetin. Additionally, excellent antioxidant activity was exhibited when tested with the DPPH assay; superoxide radical-scavenging ability and reducing power was also tested. The anticancer activity of the flavonoids was assessed using HeLa cervical cancer cells, and it was observed that increasing concentrations of olive leaf flavonoids resulted in decreased cancer cell viability. These results suggest that the flavonoids from olive leaves could be used as a potential source of natural antioxidants for the pharmaceutical and food industries.

scholarly journals Effects of Ultrasound-Assisted Extraction and Solvent on the Phenolic Profile, Bacterial Growth, and Anti-Inflammatory/Antioxidant Activities of Mediterranean Olive and Fig Leaves Extracts

Molecules ◽  
2020 ◽  
Vol 25 (7) ◽  
pp. 1718 ◽  
Author(s):  
Cristina Alcántara ◽  
Tihana Žugčić ◽  
Radhia Abdelkebir ◽  
Jose V. García-Pérez ◽  
Anet Režek Jambrak ◽  
...  
Keyword(s):  
Bioactive Compounds ◽  
Bacterial Growth ◽  
Extraction Methods ◽  
Olive Leaves ◽  
Ultrasound Assisted Extraction ◽  
Phenolic Profile ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
Conventional Extraction ◽  
Anti Inflammatory

Mediterranean plants, such as fig and olive leaves, are well-known to exert beneficial effects in humans because of the presence of a wide range of bioactive compounds. However, scarce information regarding the impact of extraction methods, such as ultrasound and types of solvents, on their profile of antioxidant and anti-inflammatory compounds is provided. In addition, no information is available on the effects of extraction methods and solvents on the inhibition of pathogenic bacteria or promoting probiotic growth. In this scenario, this study was aimed to study the effects of ultrasound-assisted extraction (UAE) and solvent on the phenolic profile (Triple TOF-LC-MS/MS), antioxidant and anti-inflammatory compounds of olive and fig leaves. Results showed that UAE extracted more carotenoids compared to conventional extraction, while the conventional extraction impacted on higher flavonoids (olive leaves) and total phenolics (fig leaves). The antioxidant capacity of aqueous extract of fig leaves was three times higher than the extract obtained with ethanol for conventional extraction and four times higher for UAE. In general terms, hydroethanolic extracts presented the highest bacterial growth inhibition, and showed the highest anti-inflammatory activity. In conclusion, these side streams can be used as sources of bioactive compounds for further development of high-added-value products.

scholarly journals Optimization of Ultrasound-Assisted Extraction of Antioxidant Polyphenols from the Seed Coats of Red Sword Bean (Canavalia gladiate (Jacq.) DC.)

Antioxidants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 200 ◽  
Author(s):  
Yue Zhou ◽  
Xiao-Yu Xu ◽  
Ren-You Gan ◽  
Jie Zheng ◽  
Ya Li ◽  
...  
Keyword(s):  
Extraction Method ◽  
Natural Antioxidants ◽  
Extraction Time ◽  
Antioxidant Compounds ◽  
Extraction Temperature ◽  
Ultrasound Assisted Extraction ◽  
Solid Ratio ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
Seed Coats

The seed coat of red sword bean (Canavalia gladiata (Jacq.) DC.) is rich in antioxidant polyphenols. It is often discarded as a byproduct with the consumption of red sword bean, since it is very thick and not consumed by people. The aim of this study was to develop an ultrasound-assisted extraction method to extract natural antioxidants from the seed coats. The extraction process was optimized by using response surface methodology. After the single-factor experiments, three key factors, including ethanol concentration, liquid/solid ratio, and extraction time, were selected and their interactions were studied using a central composite design. The optimal extraction condition was 60.2% hydroethanol, a liquid/solid ratio of 29.3 mL/g, an extraction time of 18.4 min, an extraction temperature of 50 °C, and ultrasound power of 400 W. Under the optimal conditions, antioxidant activity of the extract was 755.98 ± 10.23 μmol Trolox/g dry weight (DW), much higher than that from maceration (558.77 ± 14.42 μmol Trolox/g DW) or Soxhlet extraction (479.81 ± 12.75 μmol Trolox/g DW). In addition, the main antioxidant compounds in the extract were identified and quantified by high-performance liquid chromatography–diode array detection–tandem mass spectrometry (HPLC–DAD–MS/MS). The concentrations of digalloyl hexoside, methyl gallate, gallic acid, trigalloyl hexoside, and digallic acid were 15.30 ± 0.98, 8.85 ± 0.51, 8.76 ± 0.36, 4.27 ± 0.21, and 2.89 ± 0.13 mg/g DW. This study provides an efficient and green extraction method for the extraction of natural antioxidants from the bean coat of red sword bean. The extract of antioxidants might be added into functional foods or nutraceuticals with potential beneficial functions.

scholarly journals Ultrasound-Assisted Extraction of Total Acetogenins from the Soursop Fruit by Response Surface Methodology

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1139 ◽  
Author(s):  
Gabriela Aguilar-Hernández ◽  
María de los Ángeles Vivar-Vera ◽  
María de Lourdes García-Magaña ◽  
Napoleón González-Silva ◽  
Alejandro Pérez-Larios ◽  
...  
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Large Scale ◽  
Raw Material ◽  
Ultrasound Assisted Extraction ◽  
Fruit Peel ◽  
Optimal Method ◽  
Assisted Extraction ◽  
Ultrasound Assisted ◽  
By Products

The soursop fruit or Annona muricata (A. muricata) fruit is recognized by its bioactive compounds and acetogenins (ACG) are among the most important. The effect of ACGs, with greater importance in health, is that they present anti-tumor activity; however, the methods of extraction of ACGs are very slow and with a high expenditure of solvents. To our knowledge, there is no report of an optimal method for the extraction of acetogenins from the Annonaceae family by ultrasound-assisted extraction (UAE); therefore, the aim was to find the best UEA conditions of acetogenins from A. muricata fruit (peel, pulp, seed, and columella) by using response surface methodology. The effect of amplitude (40%, 70%, and 100%), time (5, 10, and 15 min), and pulse-cycle (0.4, 0.7, and 1 s) of ultrasound at 24 kHz was evaluated on the total acetogenin content (TAC). Optimal extraction conditions of acetogenins (ACGs) with UEA were compared with the extraction of ACGs by maceration. The optimal UEA conditions in the A. muricata pulp and by-products were dependent on each raw material. The highest TAC was found in the seed (13.01 mg/g dry weight (DW)), followed by the peel (1.69 mg/g DW), the pulp (1.67 mg/g DW), and columella (1.52 mg/g DW). The experimental TAC correlated well with the model (Adjusted R2 with values between 0.88 and 0.97). The highest effectiveness in ACG extraction was obtained in seeds and peels using UEA compared to extraction by maceration (993% and 650%, respectively). The results showed that A. muricata by-products are an important source of ACGs and that UAE could be a viable alternative, with high potential for large-scale extraction.

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