Detection of irradiated lamb meat with bone: effect of chilled storage and cooking on esr signal strength

Abstract

The effect of gamma-irradiation doses of 1, 2, 4 and 5 kGy on ESR signal intensity in pre-packed irradiated lamb meat chunks containing bones was studied. Irradiationinduced a characteristic ESR signal in bone that was not detected in non-irradiated samples and its intensity was proportional to irradiation dose up to 5 kGy. In samples irradiated to 2.5 kGy for shelf-life enhancement, ESR signal intensity was monitored immediately after irradiation and subsequently at weekly intervals during storage at 0-3 ЊC and after cooking by different methods. Hind leg bones (femur) displayed a higher signal intensity than rib bones. The ESR signal intensity faded by 30 and 42% during 4 weeks at 0-3 ЊC in hind leg and rib bones, respectively. The magnitude of ESR signal in hind leg bone declined by a maximum of 30% upon pressure cooking (for 15 min), 10% on microwave cooking (for 5 min) and 13% after boiling (for 30 min). However, in the case of rib bones, all cooking methods reduced the ESR signal by about 40%. Storage of irradiated freeze-dried bone powder samples at ambient temperature also resulted in slight reduction in ESR signal intensity. Results point to the suitability of ESR technique for detection of irradiated lamb meat even after storage or cooking, and also in samples that had been stored and then cooked.

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

“…The ESR spectra of bone powder prepared from all samples were examined for the presence of a typical radiation induced signal with g⊥ = 2.0022 and g ll = 1.9976 (Desrosiers & Simic, 1988; Morehouse et al. , 1991; Chawla et al. , 1999, 2002).…”

“…In India, irradiation treatment of meat and meat products (including chicken) up to 4 kGy has been permitted for domestic marketing and consumption by the Ministry of Health since April 1998. In our previous studies, we have demonstrated the practicality of ESR spectroscopy to detect irradiation treatment in bone‐in lamb meat chunks (Chawla et al. , 1999, 2002).…”

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

“…In 1999, a group of India scientists studied the effects of c-irradiation at dose levels of 1, 2, 4, and 5 kGy on ESR signal intensity in the lamb meat chunks with hind leg (femur) and rib bones [56]. They demonstrated that irradiation at 2.5 kGy generated detectable levels of free radicals in the lamb bones regardless of bone type, but the intensity of ESR signal was much higher in the hind leg bone than that in rib bone.…”

“…Furthermore, the ESR signal intensity was stable for up to 7 months when 1 and 2 kGy irradiation was used to treat the lamb samples, whereas ESR signal intensity decreased at the storage time of 3 and 4 months for meat samples treated with 4 and 5 kGy irradiation. In addition, it was observed that ESR signal was still detectable after cooking and chilled storage, although conventional cooking procedures including boiling, pressure cooking, and microwaving, resulted in a reduction in ESR signal intensity in the cooked lamb meat products [56]. 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].…”

“…In addition, it was observed that ESR signal was still detectable after cooking and chilled storage, although conventional cooking procedures including boiling, pressure cooking, and microwaving, resulted in a reduction in ESR signal intensity in the cooked lamb meat products [56]. 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.…”