Evaluation of antioxidant activity of olive leaf extract obtained by ultrasound‐assisted extraction and their antimicrobial activity against bacterial pathogens from food

2021 ◽  
Author(s):  
Jasminka Giacometti ◽  
Sanja Milovanović ◽  
Diana Jurčić Momčilović ◽  
Marina Bubonja‐Šonje
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Leaf Extract ◽  
Bacterial Pathogens ◽  
Olive Leaf ◽  
Ultrasound Assisted Extraction ◽  
Olive Leaf Extract ◽  
Assisted Extraction ◽  
Ultrasound Assisted

scholarly journals Improving the Biological Value of Olive and Soybean Oil Blends with Olive Leaf Extract Obtained by Ultrasound-Assisted Extraction towards the Preparation of a Sauce Product

Life ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 974
Author(s):  
Mohammad Amin Aliyari ◽  
Karamatollah Rezaei
Keyword(s):  
Oxidative Stability ◽  
Olive Oil ◽  
Leaf Extract ◽  
Control Sample ◽  
Olive Leaf ◽  
Ultrasound Assisted Extraction ◽  
Olive Leaf Extract ◽  
Polyphenolic Extract ◽  
Assisted Extraction ◽  
Ultrasound Assisted

French sauce from different blends of soybean and olive oils was prepared and the oxidative stability of the optimum sauce sample, enriched with various amounts of olive leaf polyphenolic extract (OLE) (obtained via ultrasound-assisted extraction), was investigated over 90 days of storage. The microbiological and sensory properties of the samples containing the optimum amounts of OLE, as a substitution for synthetic preservatives, were studied. According to the results, the addition of olive oil at higher levels (75% and 100%) could affect the physicochemical properties of the sauce as compared to the control sample. It was also found that the addition of olive oil (up to 50%) would not significantly impact the sauce properties. Regarding the OLE enrichment in the samples, it was found that high levels of OLE could improve the oxidative stability of the samples. It was also found that OLE could be used as a preservative instead of commercial ones. Overall, this study suggests the potential use of olive oil and olive leaf extract in the preparation of French sauce to boost its nutritional value and its stability.

scholarly journals Journal of Food Quality Evaluation of Effect of Extraction Solvent on Selected Properties of Olive Leaf Extract

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Won-Young Cho ◽  
Da-Hee Kim ◽  
Ha-Jung Lee ◽  
Su-Jung Yeon ◽  
Chi-Ho Lee
Keyword(s):  
Antimicrobial Activity ◽  
Antioxidant Activity ◽  
Leaf Extract ◽  
Radical Scavenging ◽  
Total Phenolic ◽  
Distilled Water ◽  
Olive Leaf ◽  
Leaf Extracts ◽  
Antioxidant Power ◽  
Olive Leaf Extract

The quest for natural preservatives and functional foods with health benefits has seen an increasing demand for natural products having therapeutic value. Herein, we investigated the influence of ethanol, methanol, acetone (50%, 70%, and 90% v/v), and distilled water on selected properties of olive leaf extract and determined the yield, total phenolic content (TPC), antioxidant activity, and antimicrobial activity. Extracts were analyzed for their oleuropein, hydroxytyrosol, and tyrosol contents by high-performance liquid chromatography (HPLC). The highest extraction yield of 20.41% was obtained when using 90 vol% methanol, while the highest total polyphenol contents of 232 and 231 mggallic-acid-equivalent/100 g were obtained for 90 vol% methanol and 90 vol% ethanol, respectively. Antioxidant activity was determined using the α,α-diphenyl-β-picrylhydrazyl (DPPH) radical scavenging assay, by determining the ferric reducing antioxidant power (FRAP), and using the Fe2+-chelating activity assay, which provided the highest values when 90 vol% methanol was used (33.84%, 0.75, and 12.91%, respectively). HPLC analysis showed that the highest oleuropein contents corresponded to the extracts obtained using 90 and 70 vol% methanol (26.10 ± 0.20 and 24.92 ± 1.22 g/L, respectively), and the highest antimicrobial activity was observed for 90 vol% methanol and distilled water. Olive leaf extracts using 90 vol% methanol had high levels of polyphenols and were highly antioxidant and antimicrobial. The results of this study facilitate the commercial applications of natural extracts with antioxidant and antibacterial activities and are expected to establish a foundation for further optimization studies.

scholarly journals 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 ◽  
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.

scholarly journals Effect of Ultrasound-Assisted Extraction Parameters on Total Polyphenols and Its Antioxidant Activity from Mango Residues (Mangifera indica L. var. Manililla)

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 94
Author(s):  
Anahí J. Borrás-Enríquez ◽  
Elizabeth Reyes-Ventura ◽  
Socorro J. Villanueva-Rodríguez ◽  
Lorena Moreno-Vilet
Keyword(s):  
Antioxidant Activity ◽  
Mangifera Indica ◽  
Central Point ◽  
Added Value ◽  
Sonication Time ◽  
Ultrasound Assisted Extraction ◽  
Extraction Technology ◽  
Total Polyphenols ◽  
Assisted Extraction ◽  
Ultrasound Assisted

Manililla is a mango variety whose residues contain bioactive compounds such as polyphenols and flavonoids, with high added value. The use of environmentally friendly extraction technology would be of great relevance; hence, this study aimed to evaluate the effect of solvent relation, sonication time and amplitude on the ultrasound-assisted extraction of total polyphenols in Manililla mango residues (peel, endocarp and kernel) and antioxidant activity. An experimental design 23 with a central point was used to evaluate the curvature behavior of the process variables. Conventional maceration was used as a control. The better conditions were obtained at the central point using 50% ethanol in water, 60% amplitude and 20 min of sonication time. We obtained values of up to 1814 mg GAE/100 g, 469 mg GAE/100 g and 672 mg GAE/100 g of total polyphenols and 1228 mg QE/100 g, 653 mg QE/100 g and 880 mg QE/100 g of total flavonoids for peel, endocarp and kernel, respectively. Mangiferin was quantified in ultrasound-assisted extraction at 150 mg/g in peel and 0.025 mg/g in the kernel, but it was not detectable in maceration. An antioxidant capacity of 87%, 14% and 83% inhibition for peel, endocarp and kernel, respectively, were obtained. Peel and kernel were the residues with higher potential as extraction material, while endocarp was not.

scholarly journals Microwave-Assisted Extraction and Ultrasound-Assisted Extraction of Bioactive Compounds from Grape Pomace

2020 ◽  
Vol 16 (1-2) ◽  
Author(s):  
Cassiano Brown da Rocha ◽  
Caciano Pelayo Zapata Noreña
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Bioactive Compounds ◽  
Grape Pomace ◽  
Total Phenolic ◽  
Microwave Assisted Extraction ◽  
Ultrasound Assisted Extraction ◽  
Microwave Assisted ◽  
Assisted Extraction ◽  
Ultrasound Assisted

AbstractThe grape pomace is a by-product from the industrial processing of grape juice, which can be used as a source of bioactive compounds. The aim of this study was to separate the phenolic compounds from grape pomace using an acidic aqueous solution with 2 % citric acid as a solvent, using both ultrasound-assisted extraction, with powers of 250, 350 and 450 W and times of 5, 10 and 15 min, and microwave-assisted extraction using powers of 600, 800 and 1,000 W and times of 5, 7 and 10 min. The results showed that for both methods of extraction, the contents of total phenolic compounds and antioxidant activity by ABTS and DPPH increased with time, and microwave at 1,000 W for 10 min corresponded to the best extraction condition. However, the contents of phenolic compounds and antioxidant activity were lower than exhaustive extraction using acidified methanol solution.

scholarly journals Optimization of Ultrasound-Assisted Extraction via Sonotrode of Phenolic Compounds from Orange By-Products

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1120
Author(s):  
María del Carmen Razola-Diaz ◽  
Eduardo Jesús Guerra-Hernández ◽  
Celia Rodríguez-Pérez ◽  
Ana María Gómez-Caravaca ◽  
Belén García-Villanova ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
High Performance ◽  
Phenolic Content ◽  
Orange Peel ◽  
Polar Compounds ◽  
Ultrasound Assisted Extraction ◽  
Assisted Extraction ◽  
Quantitative Analyses ◽  
Ultrasound Assisted

Orange peel is the main by-product from orange juice industry. It is a known source of bioactive compounds, mostly phenolic compounds, and it has been widely studied for its healthy activities. Thus, this research focuses on the establishment of ultrasound-assisted extraction of phenolic compounds in orange peel using a sonotrode. For this purpose, a Box–Behnken design of 27 experiments was carried out with four independent factors—ratio ethanol/water (v/v), time (min), amplitude (%), and pulse (%). Quantitative analyses of phenolic compounds were performed and the antioxidant activity was measured by ABTS and DPPH methods. The validity of the experimental design was confirmed by ANOVA and the optimal sonotrode extraction conditions were obtained by response surface methodology (RSM). The extracts obtained in the established conditions were analyzed by High Performance Liquid Chromatography (HPLC) coupled to mass spectrometer detector and 74 polar compounds were identified. The highest phenolic content and antioxidant activity were obtained using 45/55 ethanol/water (v/v), 35 min, amplitude 90% (110 W), and pulse 100%. The established method allows an increment of phenolics recovery up to 60% higher than a conventional extraction. Moreover, the effect of drying on phenolic content was also evaluated.

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