scholarly journals Radical Scavenging Activity of Olive Oil Phenolic Antioxidants in Oil or Water Phase during the Oxidation of O/W Emulsions: An Oxidomics Approach

Antioxidants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 996
Author(s):  
Vito Michele Paradiso ◽  
Federica Flamminii ◽  
Paola Pittia ◽  
Francesco Caponio ◽  
Carla Di Mattia

Omics approaches are recently being applied also in food lipid oxidation, to increase knowledge of oxidation and antioxidation mechanisms. The so-called oxidomics throws a wider spot of light on the complex patterns of reactions taking place in food lipids, especially in dispersed systems. This research aimed to investigate the radical scavenging activity of olive oil phenolic antioxidants (OPAs) in O/W emulsions, as affected by the phase in which they were added. This allowed one to assess whether different behaviors could be expected from antioxidants originally present in phenolic-rich olive oils compared to natural antioxidants added in the water phase during emulsion production. Hydroperoxide decomposition kinetics and the analysis of volatile pattern provided an outline of antioxidation mechanisms. Though being effective in slowing down oxidation when added both in the oil and water phase, OPAs interfered in different ways with oxidation pathways, based on the phase in which they were added. OPAs added to the water phase were more effective in slowing down hydroperoxide decomposition due to the hydrophilic radical initiator. On the other hand, OPAs present in the oil were more effective in preventing radical propagation, with relevant consequences on the volatile pattern.

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1064
Author(s):  
Giuseppe Squillaci ◽  
Alice Marchetti ◽  
Orsolina Petillo ◽  
Michela Bosetti ◽  
Francesco La Cara ◽  
...  

Olive oil dregs (OOD), which are an underutilized by-product from oil mills, were used for the extraction of antioxidant compounds. The residues from three oil mills located in Campania (Southern Italy) were extracted with acidified methanol, and hydroxytyrosol (HT) was the main phenolic compound detected. Total phenolic content (TPC) and HT amount were measured. EVO Campania oil mill provided the residue with the highest TPC and HT quantities: 6.801 ± 0.159 mg Gallic Acid Equivalents (GAE)/g OOD and 519.865 ± 9.082 μg/g OOD, respectively. Eco-friendly extractions at different temperatures and times were performed on EVO Campania OOD, obtaining 9.122 ± 0.104 mg GAE/g OOD and 541.330 ± 64.087 μg/g OOD for TPC and HT, respectively, at 121 °C for 60 min. Radical Scavenging Activity (RSA), Superoxide Scavenging Activity (SSA), and Ferric Reducing Antioxidant Power (FRAP) were measured in OOD aqueous extracts. Extract prepared at 37 °C for 60 min showed the greatest RSA and SSA values (44.12 ± 1.82 and 75.72 ± 1.78, respectively), whereas extract prepared at 121 °C for 60 min exhibited the highest FRAP value (129.10 ± 10.49 μg Ascorbic Acid Equivalents (AAE)/mg). OOD extracts were able to protect sunflower oil from oxidation for 4 weeks at 65 °C. The overall results suggest that this novel residue can be usefully valorized by providing HT-rich extracts to use as antioxidant agents.


2020 ◽  
Vol 10 (3) ◽  
pp. 133-136
Author(s):  
Ahlem Karbab ◽  
Kamel Mokhnache ◽  
Lekhmici Arrar ◽  
Abderahmane Baghiani ◽  
Seddik Khennouf ◽  
...  

The purpose of this study was to prepare three sub-fractions from Pituranthos scoparius roots (PSR), characterize their phytochemicals contents and to investigate their free radical scavenging activity by 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and hydroxyl scavenging activities. Tannins, flavonoids, steroids, and other bioactive compounds were found in the different sub-fractions. The Ethyle acetate extract (EAE) and chloroform extract (ChE) exhibited the highest antioxidant activity using ABTS (17.8 ± 0.87 µg/mL and 18.15 ± 0.68 µg/mL), respectively. Whereas, Crude extract (CrE) have been presented strong hydroxyl scavenging activity (14.9 ± 0.8 µg/mL). This study indicates that PSR extracts has potent free radical scavenging, and may prove to be of potential health benefit as well as additional resources for natural antioxidants. Keywords: Medicinal plant; phytochemical screening; sub-fractions, free radical scavenging.


2010 ◽  
Vol 5 (6) ◽  
pp. 1934578X1000500 ◽  
Author(s):  
Kuo-Chen Cheng ◽  
Man-Chun Hsueh ◽  
Hou-Chien Chang ◽  
Alan Yueh-Luen Lee ◽  
Hui-Min Wang ◽  
...  

Two novel antioxidants, obtusilactone A (1) and (-)-sesamin (2) have been identified in Cinnamomum kotoense Kanehira. Both showed effective 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity compared with vitamin C, and reducing power compared with BHA. These results suggest that these constituents of C. kotoense act as natural antioxidants and play a potential role in cancer prevention.


Author(s):  
Suresh Kumar P. Nair ◽  
Kumar Ganesan ◽  
Henok Azalewor ◽  
Neethu Letha ◽  
Sharmila Gani

Antioxidants are the chemical substances which prevent the free radicals damage in the body. Numerous researches are going globally focussed on investigating natural antioxidants of plants origins. The aims of the present study were to evaluate preliminary phytochemical investigation and in vitro antioxidant activities of Ethiopian indigenous medicinal plants, Ocimum lamiifolium Hochst. ex Benth and Ocimum basilicum L. Aqueous, benzene and hexane crude leaves extracts of O. lamiifolium and O. basilicum were subjected to qualitative phytochemical screening using standard procedures. In addition, we investigated the antioxidant potential of crude aqueous leaves extract of O. lamiifolium and O. basilicum using tests involving inhibition of superoxide anions, DPPH, H2O2, NO and ABTS. Preliminary phytochemical investigation for benzene, hexane and aqueous extracts found alkaloids, sterols, carbohydrate and glycosides, tannins and flavonoids. The fraction inhibition of lipid peroxide at the first stage of oxidation illustrated antioxidant activity of O. lamiifolium and O. basilicum as 90% and 88% compared to those of gallic acid (97%) and BHT (84%) respectively. Also, the aqueous leaves extract of O. lamiifolium and O. basilicum exhibited significant DPPH free radical scavenging activity, nitric acid free radical scavenging activity assay, superoxide anion scavenging activity, ABTS scavenging activity and hydrogen peroxide free radical scavenging assay. Our findings provide confirmation that the aqueous leaves extract of O. lamiifolium and O. basilicum are potential source of natural antioxidants, and this warranted its uses in traditional medicine systems.


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