Determining Irradiation Dose in Potato Tubers During Storage Using Reaction-Based Pattern Recognition Method.

Food irradiation is increasingly used to extend shelf life and control pests and diseases. Monitoring post-treatment doses typically relies on expensive, laborious instruments and may miss low doses. We previously proposed a chemical fingerprinting method that estimates dose based on indicator reaction rates, but this approach was tested only on freshly irradiated samples. In this study, we investigated the feasibility of determining the order of magnitude of dose in irradiated raw potato tubers after several days of storage. A completely randomized experimental design was used. Water extracts of potatoes were assayed in oxidation-reduction and aggregation reactions in 96-well plates; reaction rates were tracked by absorbance and fluorescence and analyzed chemometrically. We could distinguish dose orders of magnitude (0, 100, 1000 Gy) after 0, 2, and 6 days of storage at 4 °C. The accuracy of dose recognition on day 6 was at least 97% by using SoftMax regression (SR) or linear discriminant analysis (LDA); irradiated and non-irradiated samples were confidently distinguished using partial least square-discriminant analysis (PLS-DA). The reaction-based method of dose assessment is simple, rapid, and does not require sophisticated equipment.