Thermoluminescence response to identification of Mexican Ancho and Chipotle chilli irradiated with ¹³⁷Cs gamma photons

In this work, the thermoluminescence (TL) properties of mineral content in Mexican Ancho and Chipotle chilli were studied for their application in the detection of irradiated chilli. The Ancho and Chipotle chilli minerals show a complex TL glow curve with two overlapping peaks around 82 and 178 °C. Acceptable repeatability of TL measurements is obtained after ten irradiation-readout cycles. The dose-response of Ancho and Chipotle minerals is linear from 5 to 75 Gy, supralinear between 100 and 1000 Gy, and sublinear from 1500 to 5000 Gy. Using the TL₁/TL₂ ratio, the chilli minerals are detected as irradiated at doses ≥200 Gy. At low doses (<200 Gy) the TL glow curve shape, intensity, and temperature maximum position parameters are used for identifying irradiated chilli minerals. At 360 min of sunlight exposure, the TL intensity of Ancho and Chipotle chilli minerals decreased by 95 and 98%, respectively. On the contrary, the chilli minerals stored at room temperature, in the darkness, can be detected by TL as irradiated after 960 h (40 days) post-irradiation. The TL kinetic parameters were evaluated by the computerized glow curve deconvolution (CGCD) analysis.