Oxidation advanced processes for dairy phage inactivation

JACOB, MARÍA FIORELLA; BRIGGILER MARCÓ, MARIÁNGELES; ALFANO, ORLANDO MARIO; QUIBERONI, ANDREA DEL LUJÁN; BALLARI, MARÍA DE LOS MILAGROS

Santa Fe

Workshop; FRENCH -ARGENTINEAN WORKSHOP OF HETEROGENEOUS CATALYSIS; 2023

The following assays were performed in a laboratory scale reactor constituted by two separate compartments, an emission source constituted by seven lamps and an irradiation chamber where phage suspensions were placed for irradiation:Photocatalytic paints: phage suspensions were deposited and dried on the coated plates with photocatalytic paints (0.71 mg modified carbon doped TiO2 anatase/cm2). Inactivation assays were performed for sixteen phages, with a total time of 20 h at 30°C and 80% RH under radiation typically used for indoor illumination (λ = 360 - 720 nm). Eight phages were completely inactivated within 1.5 and 5 h of treatment, reaching reductions higher than 2.79 log orders, whereas other eight phages reduced their infectivity between 2.33 and 5.88 log orders, within 4 and 20 h. Photonic efficiencies ranged from 2.84×109 to 4.06×1012 PFU/Einstein and quantum efficiencies ranged from 6.40×109 to 9.17×1012 PFU/Einstein.Photocatalysis (TiO2, UV-A): drops of phage particles were deposited on plates coated with TiO2 (0.02 mg/cm2). Inactivation assays were performed for seventeen phages under UV-A radiation (λ = 200 - 400 nm), for a period of 3 h at 40°C and 89.5% RH. Some phages were completely inactivated after 60 - 120 min of treatment, while others maintained their infectivity even after 180 min. Photonic efficiencies ranged from 3.63×109 to 4.82×1010 PFU/Einstein and quantum efficiencies ranged from 1.03×1011 to 1.37×1012 PFU/Einstein. Photocatalytic treatments to airborne phages: three phages were completely inactivated within 100 min of treatment whereas one was partially inactivated under the same condition. Photonic efficiencies ranged from 7.65×106 to 1.59×107 PFU/Einstein and quantum efficiencies ranged from 2.66×107 to 5.53×107 PFU/Einstein.