X- and Q-band EPR studies on fine powders of irradiated plants. New approach for detection of their radiation history by using Q-band EPR spectrometry

Yordanov, N.D.; Aleksieva, Katerina

doi:10.1016/s0969-806x(03)00399-2

Cited by 32 publications

(22 citation statements)

References 8 publications

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“…As it is clear, the integral EPR intensity of gamma-radiation induced radical species is significantly related to the gamma-radiation dose, and can be well fitted using the model of saturation curve. On the other hand, it is also demonstrated that the lifetimes of gamma-radiation induced radicals are limited, as a substantial decline of integral EPR intensity was observed, in good agreement with previously published data on gamma-radiated plant materials (Yordanov et al 1998;Kispéter et al 2003;Bayram & Delincée 2004;Yordanov & Aleksieva 2004;Polovka et al 2006;. We have found that the storage interval after the radiation treatment influenced only the EPR spectra of the irradiated samples, while that of reference remained unchanged.…”

Section: Epr Investigationsupporting

confidence: 91%

“…The application of gamma-radiation on oregano samples led to the formation of additional EPR signals -(i) anisotropic triplet (A ⊥ = 0.85 mT, A  = 0.7 mT; g ⊥ = g  = 2.0061; λB pp = 0.67 mT) attributed to carbohydrate radical structures ( Vanhaelewyn et al 2000;Korkmaz & Polat 2001) and (ii) anisotropic triplet (A ⊥ = 3.0 mT, A  = 1.8 mT; g ⊥ = 2.0060, g  = 2.0050; λB pp = 1.2 mT previously attributed to "cellulose" radical species (Yordanov et al 1998;Kispéter et al 2003;Bayram & Delincée 2004;Yordanov & Aleksieva 2004). However, the EPR signal of "cellulose" radical species, which the European Committee for Standardization (CEN) in EN 1787:2000 declared as a marker of gamma-irradiation of natural cellulose-containing materials, is minimal (CEN 2000.…”

Section: Epr Investigationmentioning

confidence: 92%

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The influence of gamma-irradiation on the formation of free radicals and antioxidant status of oregano (Origanum vulgare L.)

Horváthová¹,

Suhaj²,

Polovka³

et al. 2007

Czech J. Food Sci.

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The influence of various gamma-radiation dose absorptions on oregano (<i>Origanum vulgare</i> L.) solid samples was monitored by means of electron paramagnetic resonance (EPR) spectroscopy. Further, the antioxidant activity of oregano methanol/water extracts was characterised using DPPH (1,1-diphenyl-2-picrylhydrazyl free radical); thiobarbituric acid reactive substances (TBARS); ferric reducing power (FRP); and total content of phenolic compounds (TPC) assays. EPR spectroscopy was used for the investigation of the influence of the absorbed dose on the character of the paramagnetic structures formed, as well as for their thermal stability and life-time characterisation. EPR spectrum of the reference (non-irradiated) sample represents a broad singlet line with unresolved hyperfine splitting, attributable to Mn(II) ions, upon which the additional sharp EPR signal (g = 2.0022, ΔB<sub>pp</sub> ≈ 1 mT) is superimposed, assigned to stable semiquinone radicals produced by the oxidation of polyphenolic compounds present in plants. The additional paramagnetic structures of different origin (mostly of cellulose and carbohydrate), possessing diverse thermal stability and life-time, were identified in the gamma-irradiated samples. Immediately after irradiation, a statistically significant increase was observed of the TBARS values and the total content of phenolic compounds in methanol/water oregano extract. The alterations of the antioxidant properties of oregano extracts with the time after the radiation treatment were also monitored. A substantial time-dependent decrease of antioxidant activity was observed, probably as a result of storage, with both irradiated and non-irradiated oregano samples, as obvious from the ferric reducing power test and the content of total phenolic substances. The influence of irradiation and subsequent storage of oregano samples on the DPPH radical-scavenging ability was only negligible.

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Section: Epr Investigationsupporting

confidence: 91%

Section: Epr Investigationmentioning

confidence: 92%

The influence of gamma-irradiation on the formation of free radicals and antioxidant status of oregano (Origanum vulgare L.)

Horváthová¹,

Suhaj²,

Polovka³

et al. 2007

Czech J. Food Sci.

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“…Its ability to detect radicals in dry samples makes ESR spectroscopy very useful for identifying radicals in irradiated food [5] and provides a new approach for detecting the irradiation history of food [6]. This technique has been applied to measurements of radiation-induced radicals in black pepper [7] and crude Chinese medicines [8].…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Hydroxyl Radical and Alkyl-oxy Radical Scavenging Activity of Coffee by ESR Spin Trapping Method

Kameya¹

2017

JFSE

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Abstract:We evaluated the hydroxyl and alkyl-oxy radical scavenging activity of instant coffee using an electron spin resonance (ESR) spin-trapping method, which was based the spin-trapping reagent 5-(2,2-dimethy-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO). In this method, very pure hydroxyl and alkyl-oxy radicals were generated by illuminating a phosphate buffer solution containing hydrogen peroxide and 2,2'-azobis (2-amidinopropane) dihydrochloride with a Hg-Xe arc lamp. The ESR adduct signal was sensitive and very stable. We concluded that instant coffee has high hydroxyl radical and alkyl-oxy radical scavenging activity.

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“…For the purpose of post-radiation identification of cellulose containing foods, the presence of relatively weak satellite lines of this "cellulosic" radical species was accepted as an unambiguous evidence for gamma-radiation treatment (Yordanov et al 1998. However, it was observed that the EPR intensity of the "cellulosic" triplet signal gradually decreased with the storage time, and that the rate of disappearance was dependent on temperature, humidity, the presence of oxygen, and other factors (Yordanov et al 1998(Yordanov et al , 2004Bayram & Delincée 2004;Polovka et al , 2007Suhaj et al 2006). In general, the cellulosic EPR signal disappeared within 70 days to 90 days after the irradiation process (Raffi et al 2000).…”

Section: Detection and Potential Detection Methods For Spices Irradiamentioning

confidence: 99%

Irradiation of spices - a review

Sádecká¹

2007

Czech J. Food Sci.

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Food irradiation is a process of exposing food to ionising radiation such as gamma rays emitted from the radioisotopes 60 Co and 137 Cs, or high energy electrons and X-rays produced by machine sources. The use of ionising radiation to destroy harmful biological organisms in food is considered a safe, well proven process that has found many applications. Depending on the absorbed dose of radiation, various effects can be achieved resulting in reduced storage losses, extended shelf life and/or improved microbiological and parasitological safety of foods. The most common irradiated commercial products are spices and vegetable seasonings. Spice irradiation is increasingly recognised as a method that reduces post-harvest losses, ensures hygienic quality, and facilitates trade with food products. This article reviews recent activities concerning food irradiation, focusing on the irradiation of spices and dried vegetable seasonings from the food safety aspect.

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X- and Q-band EPR studies on fine powders of irradiated plants. New approach for detection of their radiation history by using Q-band EPR spectrometry

Cited by 32 publications

References 8 publications

The influence of gamma-irradiation on the formation of free radicals and antioxidant status of oregano (Origanum vulgare L.)

The influence of gamma-irradiation on the formation of free radicals and antioxidant status of oregano (Origanum vulgare L.)

Evaluation of Hydroxyl Radical and Alkyl-oxy Radical Scavenging Activity of Coffee by ESR Spin Trapping Method

Irradiation of spices - a review

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