Characterization of Polyphenolic Compounds Extracted from Different Varieties of Almond Hulls (Prunus dulcis L.)

Ultrasound-assisted extraction (UAE) was applied as a pretreatment technique to improve the recovery of polyphenols from the almond hulls of four Tunisian and three Italian almond varieties, followed by the characterization with HPLC-DAD. The operating parameters (solid/liquid ratio, extraction time, and ethanol concentrations) were optimized using a Response Surface Methodology. A polynomial equation was calculated to describe the relationship between the operating parameters and dependent variables as total polyphenolic content (TPC) and antioxidant activity (RSA). A desirability function approach was used to determine the optimum conditions for operating parameters: a solid:solvent ratio of 2 g/100 mL, an extraction time of 13 min, and an ethanol concentration of 51.2%. Among the almond varieties, Pizzuta and Fakhfekh showed the highest polyphenol content and antioxidant activity. HPLC-DAD analysis of almond hull extracts confirmed that chlorogenic acid, catechin, and protocatechuic acid were the most important polyphenols in almond hull. The results highlighted that UAE could be an effective technique for the recovery of phenolic compounds from almond hull, thereby making this byproduct a promising source of compounds with potential applications in food and healthcare sectors.

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Optimization of Ultrasound-Assisted Extraction of Phloretin and Other Phenolic Compounds from Apple Tree Leaves (Malus domestica Borkh.) and Comparison of Different Cultivars from Estonia

Antioxidants ◽

10.3390/antiox10020189 ◽

2021 ◽

Vol 10 (2) ◽

pp. 189

Author(s):

Sana Ben-Othman ◽

Hedi Kaldmäe ◽

Reelika Rätsep ◽

Uko Bleive ◽

Alar Aluvee ◽

...

Keyword(s):

Antioxidant Activity ◽

Apple Tree ◽

Maximum Yield ◽

Plant Secondary Metabolites ◽

Polyphenolic Compounds ◽

Tree Leaves ◽

Ultrasound Assisted Extraction ◽

Assisted Extraction ◽

Ultrasound Assisted ◽

Promising Source

Polyphenolic compounds, plant secondary metabolites essential for plant survival, are known for their high antioxidant and anti-inflammatory activity. In addition, several polyphenols, such as phloretin, also have potential antiviral effects, making these compounds potential ingredients of biofunctional foods. A promising source for the extraction of phloretin is a by-product of apple production—apple tree leaves. Focusing on green technologies, the first aim of the present study was to optimize the direct ultrasound-assisted extraction conditions to gain the maximum yield of phloretin from air-dried apple leaves. For the optimization of process parameters, we applied the response surface method with Box–Behnken design. The optimal extraction conditions were extraction time 14.4 min, sonication amplitude 10% and 10 g of sample per 100 mL solvent (70% ethanol, w/w). Using these conditions, we assessed the content of individual and total polyphenolic compounds along with antioxidant activity in the leaves of different autumn and winter apple cultivars grown in Estonia. The analyses were carried out with chromatographic (HPLC-DAD-MS/MS) and spectrophotometric methods. The phloretin concentration ranged from 292 to 726 µg/g and antioxidant activity from 6.06 to 11.42 mg GA eq./g, these being the highest in the local winter cultivars ‘Paide taliõun’ and ‘Tellissaare’, respectively.

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Valorization of Agri-Food Waste from Pistachio Hard Shells: Extraction of Polyphenols as Natural Antioxidants

Resources ◽

10.3390/resources10050045 ◽

2021 ◽

Vol 10 (5) ◽

pp. 45

Author(s):

Nunzio Cardullo ◽

Melania Leanza ◽

Vera Muccilli ◽

Corrado Tringali

Keyword(s):

Antioxidant Activity ◽

Ethanol Extract ◽

Natural Antioxidants ◽

Total Phenolic ◽

Industrial Processing ◽

Phenolic Constituents ◽

Potential Applications ◽

Hard Shell ◽

Promising Source ◽

By Products

The agricultural processing industry usually generates a remarkable amount of by-products rich in bioactive compounds, which can be exploited for agri-food or nutraceutical applications. Pistachio’s hard shell is one of the major by-products from pistachio industrial processing. The aim of this work was the evaluation of pistachio shells as a potential source of natural antioxidants. We evaluated different extraction procedures by measuring total phenolic content, total flavonoid content and antioxidative activity (DPPH•, TEAC and ORAC). The microwave-assisted ethanol extract turned out to be the most promising and was fractionated by XAD-16 column chromatography, affording six fractions analyzed through HPLC/ESI-MS/MS and 1H-NMR to identify the main antioxidative constituents. Fractions Fr4–Fr6 demonstrated the highest antioxidant activity. Gallic acid and a monogalloylglusose isomer are the main phenolic constituents of Fr4. Both simple and complex phenolics, such as flavonoids and hydrolysable tannins, were identified in fractions Fr5 and Fr6; pentagalloylglucose and kaempferol, well-known for their antioxidant activity, are the most abundant constituents. The results highlighted that the proposed methodology can be an effective way to recover bioactive phenolic compounds from pistachio hard shell, making this by-product a promising source of compounds with potential applications in food and healthcare sectors.

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Design and Optimization of Ultrasound Assisted Extraction of Curcumin as an Effective Alternative for Conventional Solid Liquid Extraction of Natural Products

Natural Product Communications ◽

10.1177/1934578x0900400121 ◽

2009 ◽

Vol 4 (1) ◽

pp. 1934578X0900400 ◽

Cited By ~ 4

Author(s):

Vivekananda Mandal ◽

Saikat Dewanjee ◽

Ranabir Sahu ◽

Subhash C. Mandal

Keyword(s):

Curcuma Longa ◽

Optimization Technique ◽

Extraction Procedure ◽

Liquid Extraction ◽

Extraction Time ◽

Ultrasound Assisted Extraction ◽

Assisted Extraction ◽

Ultrasound Assisted ◽

Solid Liquid Extraction ◽

Solid Liquid

The first step in the qualitative and quantitative analysis of medicinal plant constituents is the extraction step. Ideally, an extraction procedure should be exhaustive with respect to the constituents to be analyzed, rapid, simple, and for routine analysis amenable to automation. Usually, the traditional techniques require long extraction times, with more consumption of energy resources and organic solvent, have low efficiency and are often unsafe for thermolabile botanicals. The Taguchi based optimization technique was adapted for the process optimization of ultrasound assisted extraction (UAE) of Curcuma longa to identify the effect of four major factors namely, extraction time, solvent viscosity, grinding degree and solvent volume on the percentage extraction of curcumin. The reproducibility and recovery of the method was also investigated. The efficiency of the new extraction method was then compared with conventional solid liquid extraction procedures. Using this novel method, long hours of conventional Soxhlet extraction were cut down to 70 minutes of UAE with greater reproducibility and recovery. The study clearly shows that this method can be effectively utilized for cutting down long extraction time of botanicals to just a few minutes without the aid of heat.

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Cnicus benedictus Oil as a Raw Material for Biodiesel: Extraction Optimization and Biodiesel Yield

Sustainability ◽

10.3390/su132313193 ◽

2021 ◽

Vol 13 (23) ◽

pp. 13193

Author(s):

Petronela Lina Matei ◽

Cristina Busuioc ◽

Niculina Ionescu ◽

Anicuta Stoica-Guzun ◽

Nicoleta-Aurelia Chira

Keyword(s):

Extraction Methods ◽

Raw Material ◽

Extraction Time ◽

Process Efficiency ◽

Liquid Ratio ◽

Ultrasound Assisted Extraction ◽

Batch Extraction ◽

Assisted Extraction ◽

Ultrasound Assisted ◽

Solid Liquid

Cnicus benedictus fruits were used as raw material to extract oil, and the resulting oil was converted into biodiesel. Two extraction methods were tested: batch extraction, and ultrasound assisted extraction. Response surface methodology was considered for the optimization of the process efficiency. The selected key independent variables were temperature, extraction time, and solid/liquid ratio for batch extraction and ultrasound intensity, temperature, and extraction time for the ultrasound assisted extraction, respectively. The optimal working conditions are different for the two extraction techniques, with respect to temperature, solid/liquid ratio, and extraction time, respectively, leading to higher extraction efficiency in the case of the ultrasound-assisted extraction. Cnicus benedictus oil obtained under the optimal extraction conditions was further esterified with methanol under acid catalysis to yield biodiesel. The biodiesel was characterized through 1H-NMR and the main fuel properties were determined.

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Optimization of Ultrasonic Assisted Extraction Process on Antioxidant Activity of Honje Fruit Extract (Etlingera elatior) Using Surface Response Method

Jurnal Kimia VALENSI ◽

10.15408/jkv.v7i2.21396 ◽

2021 ◽

Vol 7 (2) ◽

pp. 118-128

Author(s):

Artta Gracia Malau ◽

Asri Widyasanti ◽

Selly Harnesa Putri

Keyword(s):

Antioxidant Activity ◽

Total Yield ◽

Extraction Process ◽

Extraction Time ◽

Ultrasound Assisted Extraction ◽

Assisted Extraction ◽

Ultrasonic Assisted ◽

Surface Response Method ◽

Response Method ◽

Etlingera Elatior

Honje fruit (Etlingera elatior) contains bioactive compounds as antioxidants. An antioxidant can be obtained by extraction. This research aimed to determine the best combination of solvent amount and extraction time to produce the optimal yield and antioxidant activity. The extraction method was UAE (Ultrasound Assisted Extraction) using ethanol 96% solvent amount 125 mL to 250 mL and time level of 30 to 60 minutes. The RSM (Response Surface Methodology) in the Design Expert 11 application was used to arrange the extraction combination treatment, which resulted in 13 runs. Parameters analyzed were total yield, antioxidant activity, pH, specific gravity, and color. The results showed that total yield was revealed quadratic, Y1 = 19.05 – 1.76A + 0.32B – 0.002AB + 0.023A2 – 0.0005B2 and the antioxidant activity was revealed linear, Y2 = 408.147 – 6.424A + 0.326B. The optimum treatment was achieved in the amount of solvent 174.815 ml and extraction time of 60 minutes resulted in a total yield of 17.125% and antioxidant activity of 77.55 ppm that could be classified as strong.

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Ultrasound-assisted extraction of polyphenols from Thymus serpyllum and its antioxidant activity

Hemijska industrija ◽

10.2298/hemind150629044j ◽

2016 ◽

Vol 70 (4) ◽

pp. 391-398 ◽

Cited By ~ 3

Author(s):

Aleksandra Jovanovic ◽

Verica Djordjevic ◽

Gordana Zdunic ◽

Katarina Savikin ◽

Dejan Pljevljakusic ◽

...

Keyword(s):

Antioxidant Activity ◽

Particle Size ◽

Influential Factors ◽

Extraction Time ◽

Optimum Process ◽

Total Phenol Content ◽

Ultrasound Assisted Extraction ◽

Assisted Extraction ◽

Ultrasound Assisted ◽

Thymus Serpyllum

The present study was designed to establish and optimize a method for extracting natural bioactive compounds from Thymus serpyllum which possess antioxidant, antimicrobial, antispasmotic and stimulant properties. Ultrasound-assisted extraction (UAE) is a well-established method in the processing of plant material, particularly for extraction of bioactive substances such as polyphenols. The influential factors including extraction time (3, 7 and 10 minutes), solid:solvent ratio (1:10, 1:20 and 1:30) and particle size (0.3, 0.7 and 1.5 mm), have been studied to optimize the extraction process, while using 30% ethanol as an extraction medium and amplitude set to 65%. The yield of UAE was expressed via total phenol content and antioxidant activity of the obtained extracts. The optimum process paremeters were found to be: extraction time, 3 min; solid:solvent ratio, 1:30; particle size, 0.3 mm. Under these conditions, the yield of total polyphenols was raised up to 23.03 mg/L GA and the highest antioxidant activity was recorded (10.32 mmol/mg Trolox and IC50 3.00 mg/ml).

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THE IMPACT OF PLANT MATERIAL FREEZING AND EXTRACTANT ACIDIFYING ON THE ANTIOXIDANT POTENTIAL AND PIGMENTS CONTENT IN EXTRACTS AND RAW MATERIALS OF DIFFERENT CARROT VARIETIES

Acta Scientiarum Polonorum Hortorum Cultus ◽

10.24326/asphc.2021.2.4 ◽

2020 ◽

Vol 20 (2) ◽

pp. 33-42

Author(s):

Anna Muzykiewicz-Szymańska ◽

Joanna Zielonka-Brzezicka ◽

Adam Klimowicz

Keyword(s):

Antioxidant Activity ◽

Antioxidant Activities ◽

Raw Materials ◽

Raw Material ◽

Extraction Time ◽

Antioxidant Potential ◽

Ultrasound Assisted Extraction ◽

Assisted Extraction ◽

The Impact

The antioxidant activities of extracts of purple, yellow and orange carrot varieties were evaluated by in vitro methods i.e. DPPH, ABTS, FRAP, and CUPRAC. The total polyphenols concentration was evaluated using Folin-Ciocalteu technique. The content of anthocyanins, chlorophylls and carotenoids was evaluated in fresh and frozen carrots. The anthocyanin concentration was also determined in carrot extracts. The effect of certain parameters of ultrasound-assisted extraction, i.e. extraction time, concentration and acidifying of extractant, as well as the type of raw material (fresh or frozen) was analyzed. The antioxidant potential as well as content of polyphenols and plant pigments were the highest in purple carrot extracts. The most effective extractant seems to be 70% (v/v) ethanol. The extension of the extraction time, in majority of cases, led to an increase of antioxidant activity of extracts, whereas the freezing of raw material generally decreased the above-mentioned activities. The effect of acidification of extractant is ambiguous and depends on the method applied to evaluate antioxidant activity.

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Optimization of Flavonoid Extraction from Xanthoceras sorbifolia Bunge Flowers, and the Antioxidant and Antibacterial Capacity of the Extract

Molecules ◽

10.3390/molecules27010113 ◽

2021 ◽

Vol 27 (1) ◽

pp. 113

Author(s):

Henghui Zhang ◽

Xiaoli Wang ◽

Dongliang He ◽

Dongliang Zou ◽

Runzhu Zhao ◽

...

Keyword(s):

Radical Scavenging ◽

Natural Antioxidants ◽

Extraction Process ◽

Extraction Yield ◽

Ultrasound Assisted Extraction ◽

E Coli ◽

Assisted Extraction ◽

Potential Applications ◽

Pharmaceutical Industries ◽

Solid Liquid

In the present work, the extraction process of total flavonoids (TFs) from X. sorbifolia flowers by ultrasound-assisted extraction was optimized under the response surface methodology (RSM) on the basis of single-factor experiments. The optimal extraction conditions were as follows: ethanol concentration of 80%, solid–liquid ratio of 1:37 (g/mL), temperature of 84 °C, and extraction time of 1 h. Under the optimized conditions, the extraction yield of the TFs was 3.956 ± 0.04%. The radical scavenging capacities of TFs against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) were much greater than that of rutin. The results of antibacterial experiments indicated that the TFs displayed strong inhibitory activities on E. coli, S. aureus and Bacillus subtilis. Therefore, X. sorbifolia flowers can be used as a novel source of natural flavonoids, and the TFs have potential applications as natural antioxidants or antibacterial agents in the food and pharmaceutical industries.

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Sustainable Extraction Techniques for Obtaining Antioxidant and Anti-Inflammatory Compounds from the Lamiaceae and Asteraceae Species

Foods ◽

10.3390/foods10092067 ◽

2021 ◽

Vol 10 (9) ◽

pp. 2067

Author(s):

Marisol Villalva ◽

Susana Santoyo ◽

Lilia Salas-Pérez ◽

María de las Nieves Siles-Sánchez ◽

Mónica Rodríguez García-Risco ◽

...

Keyword(s):

Antioxidant Activity ◽

Total Phenolic ◽

Volatile Fraction ◽

Ultrasound Assisted Extraction ◽

Pure Ethanol ◽

Vast Number ◽

Flavonoid Aglycones ◽

Bioactive Ingredients ◽

Anti Inflammatory ◽

Promising Source

Melissa officinalis L. and Origanum majorana L., within Lamiaceae family, and Calendula officinalis L. and Achillea millefolium L., within the Asteraceae, have been considered a good source of bioactive ingredients with health benefits. In this study, the supercritical fluid extraction (SFE) using pure CO2, and the ultrasound assisted extraction (UAE) were proposed as green techniques to obtain plant-based extracts with potential antioxidant and anti-inflammatory activities. Higher values of total phenolic content and antioxidant activity were achieved in UAE ethanol:water (50:50, v/v) extracts. Meanwhile, UAE pure ethanol extracts showed greater anti-inflammatory activity. RP-HPLC-PAD-ESI-QTOF-MS/MS analysis showed a vast number of phenolic compounds in the extracts, including unreported ones. O. majorana ethanol:water extract presented the highest content of phenolics and antioxidant activity; among its composition, both rosmarinic acid and luteolin glucoside derivatives were abundant. The pure ethanol extract of A. millefolium resulted in an important content of caffeoylquinic acid derivatives, luteolin-7-O-glucoside and flavonoid aglycones, which could be related to the remarkable inhibition of TNF-α, IL-1β and IL-6 cytokines. Besides, borneol and camphor, found in the volatile fraction of A. millefolium, could contributed to this latter activity. Thus, this study points out that O. majorana and A. millefolium are considered a promising source of bioactive ingredients with potential use in health promotion.

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