Effect of Optimized UV-LED Technology on Modeling, Inactivation Kinetics and Microbiological Safety in Tomato Juice.

This research analyzed, optimized and modeled the inactivation kinetics of pathogenic bacteria (PB1: O157:H7 and PB2: ) and determined the microbiological safety of tomato juice processed by UV-LED irradiation and heat treatment. UV-LED processing conditions were optimized using response surface methodology (RSM) and were 90% power intensity, 21 min and 273-275 nm (251 mJ/cm) with R > 0.96. Using the optimal conditions, levels of PB1 and PB2 resulted a log reduction of 2.89 and 2.74 CFU/mL, respectively. The Weibull model was efficient for estimating the log inactivation of PB1 and PB2 (CFU/mL). The kinetic parameter δ showed that 465.2 mJ/cm is needed to achieve a 90% log (CFU/mL) reduction in PB1 and 511.3 mJ/cm for PB2. With respect to the scale parameter > 1, there is a descending concave curve. UV-LED-treated tomato juice had an 11.4% lower count than heat-treated juice on day 28 (4.0 ± 0.82 °C). Therefore, UV-LED technology could be used to inactivate O157:H7 and , preserving tomato juice for microbiological safety, but studies are required to further improve the inactivation of these pathogens and analyze other fruit and vegetable juices.