A new approach for extension of the identification period of irradiated cellulose-containing foodstuffs by EPR spectroscopy

Yordanov, N.D.; Gancheva, V.

doi:10.1016/s0969-8043(99)00075-5

Cited by 68 publications

(53 citation statements)

References 11 publications

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“…The rise in temperature from 298 K to 353 K caused a significant and irreversible decrease of gamma-radiation induced signals. The study of the thermal stability of EPR signal can be useful in the prediction of γ-irradiation treatment of cellulose-containing samples, as recommended by Yordanov and Gancheva (2000). As we have found from the detailed simulation of the experimental EPR spectra, the decay of each individual radical structure can be well fitted to the model of Arrhenius equation and the effective parameters so obtained can be used for the radical thermal stability assessment.…”

Section: Epr Investigationmentioning

confidence: 95%

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 Investigationmentioning

confidence: 95%

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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“…EN 1784 and EN 1785 describe methods for the detection of irradiated food containing fat, and EN 1786 a method for the detection of irradiated food containing bone. Unfortunately, their application is limited by the lifetime of the radiolytically produced free radicals (Yordanov et al 1998;Formanek et al 1999;Raffi et al 2000;Yordanov et al 2000;Delincée & Soika 2002;Bayram & Delincée 2004;Suhaj et al 2006;Polovka et al 2006Polovka et al , 2007. Raffi and Stocker (1996) observed that, even though electron spin resonance is known to be a very sensitive method, in the case of spices it did not lead to favourable results because the main radio-induced signal decreased too fast with the storage time and disappeared before the maximal usual commercial storage time.…”

Section: Detection and Potential Detection Methods For Spices Irradiamentioning

confidence: 99%

“…Consequently, the method was deemed to fail in the verification of the gamma-radiation treatment and, consequently, it was recommended that thermoluminescence techniques should be used (Yordanov et al 1998;Raffi et al 2000;Delincée & Soika 2002;Bayram & Delincée 2004). Recently, Yordanov et al (2000) pointed to the different thermal behaviour of EPR signals of non-irradiated and gamma-radiation treated foods containing cellulose, even after a long storage period after radiation, when the specific "cellulosic" EPR signal is extremely low, and recommended this technique as a method to identify gamma-radiation processed foods. Formanek et al (1999) utilised EPR spectroscopy and viscometry (with two different sample preparation methods) to detect irradiated black pepper samples.…”

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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“…The heating for 3 min induced a change in food ingredients that resulted from the radical decay. Yordanov et al [14] have reported that the amount of radicals in the irradiated pepper decreased to the level of 50% by a one-hour heat treatment at 60~…”

Section: Significance Of Heat Treatmentmentioning

confidence: 99%

An electron spin resonance study of radical decay in γ-ray irradiated pepper by thermal treatments

Ukai

Shimoyama

2003

Appl. Magn. Reson.

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We examined by electron spin resonance (ESR) spectroscopy the thermal decay of radicals as induced by "/-irradiation on pepper. Upon irradiation, the satellite signals were newly induced and appeared at the symmetric positions of the organic free radical, i.e., the g = 2.0 signal. Heat treatment decreased the satellite signals exponentially. The ESR signal of the pepper heated for more than 10 min was essentially the same as that before irradiation. To evaluate the radical decay by heat treatment, we formulated a time-dependent master equation. We could evaluate the time constant of the radical decay on the basis of the general solution of the equation together with the nonlinear least-squares method.

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A new approach for extension of the identification period of irradiated cellulose-containing foodstuffs by EPR spectroscopy

Cited by 68 publications

References 11 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.)

Irradiation of spices - a review

An electron spin resonance study of radical decay in γ-ray irradiated pepper by thermal treatments

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