scholarly journals Monitoring lipid oxidation events at frying temperatures through radical scavenging assays

2007 ◽  
Vol 13 (3) ◽  
pp. 163-166 ◽  
Author(s):  
Nickolaos Chantzos ◽  
Constantinos Georgiou

This communication proposes an alternative approach for monitoring oils during thermal stress at frying temperatures through radical scavenging assays. Oxidation events for extra virgin olive, pomace, sesame, sunflower, soybean, corn and of a commercial blend of oils are followed through the DPPH assay during heating at 100, 150 and 190?C. Radical scavenging activity decrease expressed as trolox equivalent antioxidant capacity (?TEAC, mmol trolox kg-1 oil) is found to be linearly related to increases in total oxidation (?TOTOX) values. This relationship is valid down to a certain - ?TEAC value cutoff that is different for different oils. Considerable consumption of antioxidants demonstrated by high -?TEAC values renders the linear relationship invalid indicating that antioxidants cannot control late events of oxidative damage. Radical scavenging activity is found to increase upon sesame oil heating in contrast to all other oils. It is postulated that sesamolin, a phenolic antioxidant, decomposes during heating to the more potent antioxidant sesamol accounting for the increase of radical scavenging activity upon heating. This paper demonstrates prospects of radical scavenging activity assays as a tool for monitoring oxidation events during frying and warrants further research and evaluation.

Biomolecules ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 29 ◽  
Author(s):  
Quentin Carboué ◽  
Marc Maresca ◽  
Gaëtan Herbette ◽  
Sevastianos Roussos ◽  
Rayhane Hamrouni ◽  
...  

Seven naphtho-gamma-pyrones (NγPs), including asperpyrone E, aurasperone A, dianhydroaurasperone C, fonsecin, fonsecinone A, fonsecin B, and ustilaginoidin A, were isolated from Aspergillus tubingensis G131, a non-toxigenic strain. The radical scavenging activity of these NγPs was evaluated using ABTS assay. The Trolox equivalent antioxidant capacity on the seven isolated NγPs ranged from 2.4 to 14.6 μmol L−1. The toxicity and ability of the NγPs to prevent H2O2-mediated cell death were evaluated using normal/not cancerous cells (CHO cells). This cell-based assay showed that NγPs: (1) Are not toxic or weakly toxic towards cells and (2) are able to protect cells from oxidant injuries with an IC50 on H2O2-mediated cell death ranging from 2.25 to 1800 μmol mL−1. Our data show that A. tubingensis G131 strain is able to produce various NγPs possessing strong antioxidant activities and low toxicities, making this strain a good candidate for antioxidant applications in food and cosmetic industries.


2008 ◽  
Vol 63 (7-8) ◽  
pp. 483-491 ◽  
Author(s):  
Mortada M. El-Sayed ◽  
El-Sayed S. Abdel-Hameed ◽  
Wafaa S. Ahmed ◽  
Eman A. El-Wakil

The methanol extract of the leaves of Buddleja asiatica Lour. (Loganiaceae) showed antioxidant activity toward the well known in vitro antioxidant tests such as total antioxidant capacity by the phosphomolybdenum method, free radical scavenging activity by the 1,1- diphenyl-2-picrylhydrazyl scavenging assay (DPPH assay) and hydrogen peroxide scavenging methods. Due to the high scavenging activity of the n-butanol successive fraction toward DPPH and H2O2 (SC50 = 11.99 and 18.54 μg/ml, respectively), this extract was subjected to chromatographic separation and isolation. Four non-phenolic compounds were isolated and identified on the basis of spectroscopic and chemical analyses: 1-O-ß-D-glucopyranosyl- 2-methoxy-3-(2-hydroxy-triaconta-3,12-dienoate)-glycerol (1), 3-O-[α-l-rhamnopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-glucopyranosyl-(1→2)]-ß-d-fucopyranosyl-olean- 11,13(18)-diene-3ß,23,28-triol (2), 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl- (1→4)-ß-d-glucopyranosyl-(1→3)]-ß-d-fucopyranosyl-olean-11,13(18)-diene-3ß,23,28-triol (3), and 3-O-[α-l-rhamnopyranosyl-(1→4)-ß-d-glucopyranosyl-(1→3)]-[ß-d-xylopyranosyl- (1→2)]-ß-d-glucuronopyranosyl-acid-olean-11,13(18)-diene-3ß,23,28-triol (4). The four compounds were evaluated as antioxidant agents using the three antioxidant bioassay tests.


2017 ◽  
Vol 58 (4) ◽  
Author(s):  
Ning Li ◽  
Kaijin Wang ◽  
Shiping Li ◽  
Xiangyu Zhai ◽  
Tianming Wang ◽  
...  

<p>Phytochemical investigation on the root of <em>R. laevigata</em> led the isolation and identification of two new flavonoids, (+)-catechin-8-acetic acid (<strong>1</strong>) and guibourtacacidine 4-methyl ether (<strong>2</strong>), one known flavonoid, guibourtacacidine (<strong>3</strong>), along with seven known triterpenoids, euscaphic acid (<strong>4</strong>), kajiichigoside F1 (<strong>5</strong>), nigaichigoside F2 (<strong>6</strong>), rubuside J (<strong>7</strong>), tomentic acid (<strong>8</strong>), rosamutin (<strong>9</strong>) and betulinic acid (<strong>10</strong>). Their structures were established on the basis of spectroscopic evidence and comparisons with literature data. Compounds <strong>1</strong>, <strong>2</strong> and <strong>3</strong> showed considerable radical scavenging activity in the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) assay.<strong></strong></p>


Author(s):  
Bouchra Sayed Ahmad ◽  
Thierry Talou ◽  
Evita Straumite ◽  
Martins Sabovics ◽  
Zanda Kruma ◽  
...  

This study investigated the effect of protein bread fortification with 2, 4 and 6% of cumin (Cuminum cyminum) and caraway (Carum carvi) whole seeds and by-products flour, respectively. Fortified protein bread samples were compared to control protein bread and evaluated for their sensory, color, moisture, hardness properties as well as their nutritional values. Total phenolic contents and Trolox equivalent antioxidant capacity were also analyzed. Results indicated that bread fortification shows significant effects on bread properties depending on fortification level. A higher acceptability was observed specially for bread fortified with by-products flour. Increased tendencies of color darkness, moisture content, bread hardness, nutritional values as well as total phenolic content and radical scavenging activity compared to control bread were observed as the percentage of fortification increased in both cases. The overall results showed that addition of cumin and caraway seeds and by-products flour can improve the antioxidant potential and overall quality of protein bread.


2018 ◽  
Vol 69 (2) ◽  
pp. 248 ◽  
Author(s):  
S. Turan ◽  
R. Solak ◽  
M. Kiralan ◽  
M. F. Ramadan

In the present report, the fatty acids, tocopherols, and sterol profiles as well as the total phenolics and carotenoids of rosehip (Rosa canina) seed oil were determined. The major fatty acids in the oil were linoleic and linolenic acids, comprising 54.80% and 23.47% of the total fatty acids, respectively. Other bioactive lipids in the oil included total tocopherols (786.3 mg/kg), total phenolics (37.97 mg/kg) and total carotenoids (218.8 mg/kg). Rosehip oil was rich in γ-tocopherol (472.0 mg/kg) and β‑sitosterol (78.0% of total sterols). The DPPH· (2,2′-diphenyl-1-picrylhydrazyl) radical scavenging activity of the oil showed 1.08 mg α-tocopherol/g oil and 4.18 μmol TEAC (Trolox equivalent antioxidant capacity)/g oil, respectively. The ABTS+ (2,2′-Azino-bis-3-ethylbenzothiazoline-6-sulphonic acid) radical scavenging activity of the oil showed 1.00 mg α-tocopherol/g oil and 3.02 μmol TEAC/g oil, respectively. The induction period (IP) of the oil was 3.46 h for the Rancimat test (110 °C), while the IP of oil in differential scanning calorimetry (DSC) test (100-150 °C) ranged between 0.26 and 58.06 min. The oxidative stability of the oil was determined under thermal and photo oxidation conditions. The progression of oxidation at 30 °C (under UV light) and at 60 °C (in the dark) was followed by recording the ultraviolet absorption (K232 and K270) and degradation of total tocopherols, γ-tocopherol and total carotenoids. Rapid deterioration occurred in the oil stored under UV light conditions. The information provided in the present work is of importance for using rosehip seed oil in different food and non-food applications.


2018 ◽  
Vol 16 (3) ◽  
pp. 297 ◽  
Author(s):  
Wiwit Denny Fitriana ◽  
Taslim Ersam ◽  
Kuniyoshi Shimizu ◽  
Sri Fatmawati

Moringa oleifera have been evaluated for its antioxidant activity. M. oleifera leaves were extracted with methanol, ethyl acetate, dichloromethane and n-hexane. The antioxidant activity of extracts were evaluated by 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging activity assay and an improved 2,2’-azino-bis-[3-ethylbenzothiazoline sulphonate] (ABTS) radical cation decolorization assay in vitro. Trolox was used as standard with IC50 5.89 μg/mL in DPPH assay and 3.06 μg/mL in ABTS assay. The methanol extract showed the highest free radical scavenging activity with IC50 value of 49.30 μg/mL in DPPH assay and 11.73 μg/mL in ABTS assay. This study provided that M. oleifera leaves possess antioxidant.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3278 ◽  
Author(s):  
Andrea Nemes ◽  
Erzsébet Szőllősi ◽  
László Stündl ◽  
Attila Biró ◽  
Judit Homoki ◽  
...  

Hungarian sour cherries (SC) are excellent source of anthocyanin (concentrations (100–300 mg in 100 g fresh fruit) and melatonin (0.15 mg in 100 g fresh fruit), but other flavonoid derivatives also can be isolated by aqueous alcoholic extraction. We have developed a new process for extracting non-extractable procyanidines bound to the membrane, proteins, and fibers. These compounds were seperated with UHPLC-MS methods, and the structure of individual components were identified on the basis of their mass fragmentation spectra. The antioxidant capacity of soluble and non-soluble antioxidants were measured with ferric reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity (DPPH), trolox equivalent antioxidant capacity (TEAC) assays, and compared to the new measurement methods of water-soluble antioxidant capacity (ACW), lipid-soluble antioxidant capacity (ACL). Furthermore, total phenolic content (TPC) and total procyanidin content (PAC) were determinated. As a result of our investigation, we found that the solvent combination, where in the first step is water–ethanol (1:1), then 100% ethanol were suitable for the extraction of the extractable antioxidants. However, the chemiluminescence method that is based on the elimination of the superoxide radical is more accurate than other colorimetric methods which measure antioxidant capacity.


Foods ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1617
Author(s):  
Tina Kostka ◽  
Johanna Josefine Ostberg-Potthoff ◽  
Karlis Briviba ◽  
Seiichi Matsugo ◽  
Peter Winterhalter ◽  
...  

Secondary plant metabolites, e.g., polyphenols, are widely known as health-improving compounds that occur in natural functional foods such as pomegranates. While extracts generated from these fruits inhibit oxidative stress, the allocation of these effects to the different subgroups of substances, e.g., anthocyanins, “copigments” (polyphenols without anthocyanins), or polymeric compounds, is still unknown. Therefore, in the present study, polyphenols from pomegranate juice were extracted and separated into an anthocyanin and copigment fraction using adsorptive membrane chromatography. Phenolic compounds were determined by high performance liquid chromatography with photodiode array (HPLC–PDA) detection and HPLC-PDA electrospray ionization tandem mass spectrometry (HPLC–PDA–ESI–MS/MS), while the free radical scavenging activity of the pomegranate XAD‑7 extract and its fractions was evaluated by the Trolox equivalent antioxidant capacity (TEAC) assay and electron spin resonance (ESR) spectroscopy. Compared to juice, the total phenolic content and free radical scavenging potential was significantly higher in the pomegranate XAD-7 extract and its fractions. In comparison to the anthocyanin and copigment fraction, pomegranate XAD-7 extract showed the highest radical scavenging activity against galvinoxyl and DPPH radicals. Moreover, the enriched XAD-7 extract and its fractions were able to protect human hepatocellular HepG2 cells against oxidative stress induced by hydrogen peroxide. Overall, these results indicated that anthocyanins and copigments act together in reducing oxidative stress.


2013 ◽  
Vol 8 (5) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Marija Karapandzova ◽  
Bujar Qazimi ◽  
Gjoshe Stefkov ◽  
Katerina Bačeva ◽  
Trajče Stafilov ◽  
...  

Chemical characterization was made of over-ground flowering parts of Sideritis scardica from R. Macedonia and S. raeseri from both R. Macedonia and R. Albania. GC/FID/MS investigation of the n-hexane extracts revealed more than 90 components, dominated by diterpenes and hydrocarbons. The most abundant components were hentriacontane, nonacosane and heptacosane, and two other components both with MW=286, probably diterpenes, which were not fully identified. In addition, the content of total phenols, made by the Folin-Cioclateu method, ranged up to 50.8 and up to 48.9 mg gallic acid/g for S. scardica and S. raeseri, respectively. Free radical scavenging activity was evaluated by DPPH assay and the activity, presented as IC50 values, ranged from 3.2-8.9 mg/mL and 7.6-12.6 mg/mL for S. scardica and S. raeseri, respectively. The content of twenty minerals in dried over-ground parts of the plants and in water tea-infusions were determined by the ICP-AES method and some of them alternatively by ETAAS. The most abundant minerals were K > Ca > Mg > P > Fe > Al > Na. The microelements and toxic elements contents were represented in the following order: Zn > Mn > B > Ba > Cu > Sr > Li > Ni > Cr > Co, and Cd > Pb > As, respectively. Water tea-infusions contained a large portion of the total K, P, Na, Cu and Pb, but smaller amounts of the other elements.


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