Use of UV-C Radiation as a Disinfection Method for the Elaboration of Minimally Processed Arugula (Eruca sativa Mill.)

Abstract

In this work the effect of disinfection with different doses of UV-C (0.34; 5.16; 10.15; 15.14 and 20.13 kJ m^-2) was evaluated as an alternative to sodium hypochlorite (NaClO, control) disinfection on microbiological and sensorial quality of minimally processed arugula (MP) maintained for 10 days at 5 °C. Arugula treated with doses of 0.34 to 10.15 kJ m^-2 had respiratory rates similar to the control, while doses of 15.14 and 20.13 kJ m^-2 significantly increased the respiration rate. During conservation, the O₂ concentration inside the containers decreased, while the CO₂ concentration increased to 13-19 % O2 and 2 to 4 % CO₂ after four days. Disinfection treatments allowed lowering the number of mesophilic aerobic, psychrophilic, enterobacteria, mold and yeast loads in raw material in 1-1.3 log cfu g^-1. Although the trend continued until 10 days of storage, the high initial load of the raw material determined that aerobic mesophilic and psychrophilic counts were higher than those allowed by the Chilean legislation. Disinfection treatments did not affect the sensory parameters of appearance and color that acceptable for consumption after 10 days. The UV-C radiation, particularly at doses of 15.14 and 20.13 kJ m^-2, is a good alternative to disinfection with NaClO in MP arugula elaboration process. However, research on adjusting the dose should continue in order to transfer the information to the productive sector.