Evaluation of HHEVC (4, 4′, 4″-tris-di-B-hydroxyethyl aminotriphenylacetonitrile) dye as a chemical actinometer in model buffers for UV treatment of apple juice and cider

The 4,4′, 4″-tris-di-B-hydroxyethylaminotriphenylacetonitrile (HHEVC) dye was evaluated for dose measurement and verification during UV treatment of apple juice and cider. A static UV system was used to measure the quantum yield of the HHEVC dye and to study effects of the chemical and physical properties such as pH, soluble solids, absorbance and turbidity on UV dose delivery in juices. The malate buffer and caramel based model was designed to mimic properties of apple juice and cider. The sensitivity of HHEVC dye to UV light was greater than that of the other standard chemical actinometers such as ferrioxalate and potassium iodide, in the dose range studied (up to 10 mJ/cm2). It was observed that the absorbance of the model apple solution and levels of the suspended particles (turbidity) affected UV dose. Reduction of UV dose was observed in malate buffer and caramel solutions when absorbance increased due to suspended solids. Chemical properties of apple juice such as °Brix and pH did not affect UV dose. A UV dose-response curve, constructed in a static UV lamp, was used for evaluating the dose delivered in the continuous UV reactor “CiderSure 1500”. The obtained results can be recommended for periodically verification of delivered UV dose in the flow- through reactors.