Chapter 5 - ESR Spectroscopy for the Identification of Irradiated Fruits and Vegetables

Abstract

Food irradiation can ensure the microbial safety and shelf life extension of the global supply of fresh fruit and vegetables. Reliable detection methods for irradiated foodstuffs can greatly enhance the widespread application of irradiation technology. Electron spin resonance (ESR) spectroscopy is able to directly analyze radiation-specific radicals (e.g., cellulose radicals and crystalline sugar radicals) that can serve as detection markers in irradiated foods. On the basis of these unique radiation-induced markers, the European Committee for Standardization has recommended ESR spectroscopy as a confirmatory technique for the identification of irradiated foods containing cellulose and crystalline sugar. This chapter focuses on the basic knowledge of food irradiation and the application of ESR spectroscopy in the detection of irradiated fruits and vegetables. The stability and specificity of the radiation-induced signals with respect to the shelf life of various fruit and vegetables are summarized. Recent investigations, limitations, and future research trends, particularly including different sample pre-treatments, improved detectability, and dose estimation, are also discussed.