Gamma-irradiated (0, 1, 5 and 10 kGy) spaghetti sauce samples were identified using photostimulated luminescence (PSL), thermoluminescence (TL) and electron spin resonance (ESR) techniques. PSL technique was used as a screening method for irradiated sauce samples, where the improved results of PSL method were observed for the freeze-dried and alcoholic-extracted samples. TL technique, through the density separation step of silicate minerals from irradiated samples, gave specific shape, intensity and occurrence of TL glow curve in a typical temperature range as well as TL ratio (TL 1/TL 2) to identify the irradiation treatment. The ESR method employed for the freeze-dried samples, showed radiation-specific cellulose signals for 5 and 10 kGy-treated samples, and the results were comparable with oven-dried samples. In general, TL technique was found the most sensitive and reliable for the identification of irradiated spaghetti sauces.

Practical Applications

The safety of food irradiation is well documented; however, this technique lacks international consensus for general applicability. Validated identification methods have prime importance for the application of different regulations regarding the international trade of irradiated food. This study comprehensively investigated the potential of different available techniques for the identification of irradiated sauce samples. Liquid samples were treated with different modified methods to find the improved identification results. The presented results may be useful for different regulatory authorities to identify or monitor irradiated spaghetti sauces.