Identification of irradiated meat using electron spin resonance spectroscopy: results of blind trials

Abstract

Two blind trials on bone-in meat chunks are reported. In total 30 or 35 coded samples were analysed for irradiation treatment using electron spin resonance (ESR) spectroscopy. In the first trial 30 samples were received from other research institutes. All samples were qualitatively identified correctly. The second trial consisted of 35 samples. They were either left unirradiated or had been irradiated at doses of 1, 2.5 or 4 kGy. All samples were qualitatively identified on the basis of the ESR spectra. Using re-irradiation, the doses received by the samples were determined with linear, quadratic or exponential equations. The quadratic or exponential equations gave more successful estimates of the irradiation dose whereas linear fit equations tended to overestimate the dose.

Scientific Opinion on the Chemical Safety of Irradiation of Food

“…ESR has been used to identify radiation treatment of various foods such as lamb meat (Chawla and Thomas, 2004), other types of meat, fish and shellfish (Miyahara et al, 2004;Sin et al, 2005), mechanically recovered poultry meat (Marchioni et al, 2005a and b), kiwi (Jo and Kwon, 2006), oats (Korkmaz and Polat, 2004), melon, pumkin and sunflower seeds (Sin et al, 2006), and cashew nuts (Bhaskar et al, 2008).…”

Application of electron spin resonance (ESR) spectrometry in nutraceutical and food research

“…It was concluded that ESR spectroscopy is an effective technique for identifying irradiated lamb meat containing bone tissue, which were explored to an irradiation dose range of 2.5 -5.0 kGy and might have been stored and/or cooked [56]. Later in 2004, Chawla and Thomas [55] reported two blind trials on ESR determination of irradiated meat containing bone tissues to demonstrate the reliability and usefulness of ESR technique in determination of the irradiated bone-in meat products. The first trial included 29 irradiated and nonirradiated bone-in lamb meat chunk samples, which were at different spoilage stages.…”

“…Extrapolation of the curve to the negative axis provides an estimation of the initial absorbed irradiation dosage in the bone and the surrounding muscle tissue. In this study, linear, quadratic, and exponential equations were used to determine the original irradiation doses in the meat samples, and were found out that quadratic and exponential equations estimated the irradiation doses better whereas linear fit equation might overestimate the irradiation level [55]. It was then concluded that ESR might be a possible method for qualitatively identifying irradiated bone-in meat samples, and for estimation of the original irradiation doses in the bone-in meat samples using the reirradiation technique [55].…”

“…Miyahara et al [53] briefly reviewed the status of food irradiation and the development of ESR methods for its determination. For a number of reasons including the regulation and consumer acceptability of food irradiation, ESR has been intensively used to investigate the free radical generation and their concentrations in the irradiated food ingredients and food products, as well as to estimate the irradiation dose of these products [7,52,54,55].…”

Application of the ESR spectroscopy to estimate the original dose in irradiated chicken bone

“…For this study, the additive dose method (Bordi et al, 1994;Chawla and Thomas, 2004) was applied; this method requires a series of additional irradiation doses; the original ESR signal amplitude, H 0 (due to the original dose D 0 ) was measured; after each added dose (D i ) the measured signal H i corresponds to the original ESR signal intensity (H 0 ) plus the contribution due to the additional dose D i . Once the relationship between the ESR signal intensity and the added dose in the sample is found, the original dose value (D 0 ) is determined from the intersection of the fitting function with the abscissa.…”