scholarly journals Pulsed Electric Field Extraction and Antioxidant Activity Determination of Moringa oleifera Dry Leaves: A Comparative Study with Other Extraction Techniques

Beverages ◽  
2019 ◽  
Vol 5 (1) ◽  
pp. 8 ◽  
Author(s):  
Eleni Bozinou ◽  
Ioanna Karageorgou ◽  
Georgia Batra ◽  
Vassilis G. Dourtoglou ◽  
Stavros I. Lalas

The scope of this work was to determine the possibility of the application of the pulsed electric field (PEF) technique to the production of extracts from Moringa oleifera plant material (freeze-dried leaves). Various PEF conditions (pulse duration—PD; and pulse interval—PI) were tested. A field strength of 7 kV/cm was used. The total phenols in the extracts were evaluated by the Folin–Ciocalteu method and the antioxidant activity was evaluated by the radical scavenging activity (DPPH•), ferric reducing antioxidant power (FRAP) and Rancimat methods. The results were compared with those of the extracts obtained using other extraction techniques, namely microwave-assisted and ultrasound-assisted extractions, simple boiling water extraction, and plain maceration with water (as the control). The highest extraction of total phenols was achieved by the PEF procedure using 40 min treatment at a PD of 20 msec and a PI of 100 μsec. Additionally, all methods for the determination of the antioxidant activity showed that the activity of the extracts was proportional to the total phenol content. Concerning the PEF procedure, a low pulse duration with a high pulse interval is proposed in order to achieve higher extraction efficiency.

2016 ◽  
Vol 23 (3) ◽  
pp. 265-276 ◽  
Author(s):  
Alifdalino Sulaiman ◽  
Mohammed Farid ◽  
Filipa VM Silva

Worldwide, apple juice is the second most popular juice, after orange juice. It is susceptible to enzymatic browning spoilage by polyphenoloxidase, an endogenous enzyme. In this study, Royal Gala apple juice was treated by thermosonication (TS: 1.3 W/mL, 58 ℃, 10 min), pulsed electric field (PEF: 24.8 kV/cm, 60 pulses, 169 µs treatment time, 53.8 ℃) and heat (75 ℃, 20 min) and stored at 3.0 ℃ and 20.0 ℃ for 30 days. A sensory analysis was carried out after processing. The polyphenoloxidase activity, antioxidant activity and total color difference of the apple juice were determined before and after processing and during storage. The sensory analysis revealed that thermosonication and pulsed electric field juices tasted differently from the thermally treated juice. Apart from the pulsed electric field apple juice stored at room temperature, the processed juice was stable during storage, since the pH and soluble solids remained constant and fermentation was not observed. Polyphenoloxidase did not reactivate during storage. Along storage, the juices’ antioxidant activity decreased and total color difference increased (up to 6.8). While the antioxidant activity increased from 86 to 103% with thermosonication and was retained after pulsed electric field, thermal processing reduced it to 67%. The processing increased the total color difference slightly. No differences in the total color difference of the juices processed by the three methods were registered after storage. Thermosonication and pulsed electric field could possibly be a better alternative to thermal preservation of apple juice, but refrigerated storage is recommended for pulsed electric field apple juice.


2021 ◽  
Vol 13 (1) ◽  
pp. 101-109
Author(s):  
Abhimanyu Thakur ◽  
NS Thakur ◽  
Hamid ◽  
Sunakshi Gautam

Wild pomegranate (Punica granatum L.) fruit arils with high acid content are processed into dried arils (anardana) which is used as an ingredient in various medicinal formulations and culinary preparations. The various phenols and flavonoids are responsible for the antioxidant activity of anardana which signifies its functional benefits. The advanced packaging techniques like vacuum packaging, can retain higher antioxidant activity characteristics during storage. So, the present studies were carried out to compare the effect of packaging on total phenols, flavonoids, DPPH (2, 2-diphenyl-1-picrylhydrazyl) antioxidant activity, metal chelating activity, FRAP (ferric reducing antioxidant power) and reducing power of anardana prepared in mechanical cabinet drier. Anardana was packed in different packaging materials and stored under ambient and refrigerated temperature conditions. The overall effect of storage during 12 months revealed that there was a significant (p< 0.05) decrease in total phenols (180.95 to 161.76 mg GAE/100 g), flavonoids (40.60 to 32.66 mg QuE/100 g), DPPH antioxidant activity (61.23 to 56.13%), metal chelating activity (22.25 to 19.37%), FRAP (34.60 to 31.73 ?M Fe2+/100 g) and reducing power (0.610 to 0.521) which was observed less in anardana packed in ALPV (aluminium laminated pouches with vacuum) followed by ALP (aluminium laminated pouches) and gunny bags. Due to slower rates of degradation of various antioxidant compounds, the changes after 12 months of storage were lower under refrigerated conditions. The total phenols, flavonoids and DPPH antioxidant activity were reduced  from 180.95 to 167.24 and 156.28 mg GAE/100 g, 40.60 to 34.95 and 30.37 mg QuE/100 g and 61.23 to 57.99 and 54.27 % in refrigerated and ambient temperature conditions, respectively.


Agronomy ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 727 ◽  
Author(s):  
Antonios Chrysargyris ◽  
Maria Mikallou ◽  
Spyridon Petropoulos ◽  
Nikolaos Tzortzakis

In the present study, the yield, the chemical composition, and the antioxidant activities of the essential oils (EOs) of eight medicinal and aromatic plants (MAPs) cultivated under two environmental conditions characterized by a different altitude (namely mountainous and plain) were evaluated. Cultivation at different environmental conditions resulted in significant differences in the chemical composition and antioxidant activity for most of the studied species. In particular, high altitudes resulted in increased phenolic compounds’ content and antioxidant activity for artemisia plants, while specific parameters increased in the case of spearmint (total phenols) and rosemary (flavonoids). In contrast, in pelargonium, all the tested parameters were positively affected in the plain area, whereas, for laurel and sage, only flavanols remained unaffected. EO yield in mountainous pelargonium and spearmint decreased while, in mountainous laurel, pelargonium and spearmint increased when compared to plain areas. In addition, the major EO constituents’ content for most of the species were affected by environmental conditions. The 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and ferric reducing antioxidant power (FRAP) were variably correlated with total phenols, flavonoids, and flavanols, depending on the species and the altitude. Lastly, in limited cases, antioxidant activity (DPPH or FRAP values) was positively correlated with some EO components (e.g., borneol and β-pinene in artemisia and laurel plants grown in the plain, respectively, or 1,8-cineole in mountainous grown verbena plants). In conclusion, environmental conditions (altitude) affected antioxidants’ content and EO yield and composition of the studied MAPs. These findings can be used to introduce cultivation of MAPs in specific ecosystems for the production of high added value products.


2021 ◽  
Vol 50 (5) ◽  
pp. 1445-1456
Author(s):  
Nur Fatin Nabilah Mohd Sahardi ◽  
Faizul Jaafar ◽  
Siti Nor Asyikin Zakaria ◽  
Jen Kit Tan ◽  
Mariam Firdhaus Mad Nordin ◽  
...  

Ginger has been proven to possess various therapeutic effects, including antibacterial, anticancer, anti-inflammatory, and antioxidant effects. However, data on the comparison of ginger antioxidant activity with that of other natural products are still lacking. This study aimed to analyse and compare the antioxidant properties of two types of Malaysian ginger extracts (GE1 and GE2) with that of selected natural products. The antioxidant activities were measured by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) and ferric reducing antioxidant power (FRAP) assays, while cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfonyl)-2H-tetrazolium (MTS) assay. The order of the DPPH scavenging activities was as follows: vitamin C > palm tocotrienol-rich fraction (TRF) > á-tocopherol > N-acetylcysteine (NAC) > Ficus deltoidea > butylated hydroxytoluene (BHT) > Centella asiatica > GE2 > GE1 > Moringa oleifera > Kelulut honey; the order of the mean FRAP value was as follows: NAC > á-tocopherol > BHT > TRF > Ficus deltoidea > Moringa oleifera > GE2 = GE1 > Centella asiatica > Kelulut honey. The viability assays showed that both ginger extracts significantly increased the percentage of viable cells (p < 0.05). In conclusion, neither of the ginger extracts was cytotoxic toward cells and both possessed comparable antioxidant properties, indicating their potential for ameliorating oxidative stress.


Antioxidants ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1554
Author(s):  
Vasileios M. Pappas ◽  
Achillia Lakka ◽  
Dimitrios Palaiogiannis ◽  
Vassilis Athanasiadis ◽  
Eleni Bozinou ◽  
...  

Olive leaves (OLL) are reported as a source of valuable antioxidants and as an agricultural by-product/waste. Thus, a twofold objective with multi-level cost and environmental benefits arises for a “green” standalone extraction technology. This study evaluates the OLL waste valorization through maximizing OLL extracts polyphenol concentration utilizing an emerging “green” non-thermal technology, Pulsed Electric Field (PEF). It also provides further insight into the PEF assistance span for static solid-liquid extraction of OLL by choosing and fine-tuning important PEF parameters such as the extraction chamber geometry, electric field strength, pulse duration, pulse period (and frequency), and extraction duration. The produced extracts were evaluated via comparison amongst them and against extracts obtained without the application of PEF. The Folin-Ciocalteu method, high-performance liquid chromatography, and differential scanning calorimetry were used to determine the extraction efficiency. The optimal PEF contribution on the total polyphenols extractability (38% increase with a 117% increase for specific metabolites) was presented for rectangular extraction chamber, 25% v/v ethanol:water solvent, pulse duration (tpulse) 2 μs, electric field strength (E) 0.85 kV cm−1, 100 μs period (Τ), and 15 min extraction duration (textraction), ascertaining a significant dependence of PEF assisting extraction performance to the parameters chosen.


Planta Medica ◽  
2016 ◽  
Vol 81 (S 01) ◽  
pp. S1-S381
Author(s):  
A da Costa Gomes ◽  
CC Malagutti Figueiredo ◽  
L Pereira Silva ◽  
EC Toledo de Mello Peixoto ◽  
RM Gonçalvez da Silva

2020 ◽  
pp. 1-16 ◽  
Author(s):  
Mozhdeh Sarraf ◽  
Adel Beig-babaei ◽  
Sara Naji-Tabasi

BACKGROUND: Barberry is a valuable plant, which is useful in the treatment of different diseases. There are valuable compounds in different parts of barberry that are pruned per year and discarded as waste. OBJECTIVE: In this study, the amount of berberine, phenolic compounds and antioxidant activity of barberry fruits, leaves, and stems of different barberry species (B.integerrima and B.thunbergii) were investigated. METHODS: Central composite design of response surface methodology (RSM) were used in this study to investigate the extraction variables (time: 2–24 h, temperature: 24–70°C and ethanol concentration: 50–90%) in the extraction of berberine from the stem of B.integrrima. The responses used as criteria were the amount of berberine, scavenging radical DPPH, and polyphenol. Also, pulsed electric field-assisted (PEF) was applied as a pretreatment (Pulse strengths of 250, 1000 and 1250 Vcm–1; Pulse numbers (n) of 50 and 100; frequency (f) of 1 Hz) and then the extraction was conducted in optimum condition. PEF increased significantly the amount of berberine. RESULTS: The stem of B.integrrima had the most amounts of antioxidant activity and berberine content, and it was selected for more investigation. The optimum condition in the maceration method was: 90% of ethanol, 70°C, and 3.36 h (141.6 min). According to the result of PEF method, the best condition for extraction of berberine from barberry stems was 1000 Vcm–1 and n = 100. CONCLUSIONS: The results demonstrated that the extract of B.integrrima stem is a good source of berberine, antioxidant, and has the potential to be applied in various industries.


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