Short Wave Ultraviolet Light (UV-C) Effectiveness in the Inactivation of Bacterial Spores Inoculated in Turbid Suspensions and in Cloudy Apple Juice

Liquid foods might present interferences in their optical properties that can reduce the effectiveness of short-wave ultraviolet radiation (UV-C) treatments used for sterilization purposes. The effect turbidity as UV-C interference factor against inactivation bacterial spores was analysed by using phosphate-buffered saline solutions (PBS) different values (2000, 2500, and 3000 NTU) which were adjusted with addition apple fibre. These suspensions inoculated Bacillus subtilis Alicyclobacillus acidoterrestris. While higher doses increased rates spores, these reduced when increased; a dose 28.7 J/mL allowed B. 3.96 Log 2000-NTU suspension compared 2.81 achieved 3000-NTU one. Spores more UV-C-resistant than A. Cloudy juice acidoterrestris processed at single pass recirculation matrix through reactor. Inactivation significantly recirculation, surpassing 5 after 125 0.13 single-pass treatment same dose. affected (absorption coefficient 254 nm turbidity) browning became higher.