Optimization of UV-C Processing of Donkey Milk: An Alternative to Pasteurization?

Abstract

The effect of UV-C light technology on the inactivation of six foodborne pathogens inoculated in raw donkey milk was evaluated. Fresh raw donkey milk was artificially inoculated with the following foodborne pathogens—L. inoccua (NCTC 11288), S. aureus (NCTC 6571), B. cereus (NCTC 7464), Cronobacter sakazakii (NCTC 11467), E. coli (NCTC 9001), Salmonella enteritidis (NCTC 6676)—and then treated with UV-C doses of up to 1300 J/L. L. innocua was the most UV-C-resistant of the bacteria tested, requiring 1100 J/L for complete inactivation, while the rest of the bacteria tested was destructed in the range of 200–600 J/L. Results obtained from this study indicate that UV-C light technology has the potential to be used as a non-thermal processing method for the reduction of spoilage bacteria and foodborne pathogens that can be present in raw donkey milk.

UV Light Application as a Mean for Disinfection Applied in the Dairy Industry

“…The light intensity at the sample location was 3.04 mW/cm 2 The application of ultraviolet light for the disinfection of milk and dairy products was a subject of much research (Table 2). The material used in these studies was milk of different species [12,16,45,46,[48][49][50], Kashar cheese [51], Fresh Kashar [52], Fiordilatte [53], fresh cheese [54], Hard cheeses [55], white American cheese [55], Ricotta [56] and Cheddar cheese [57,58]. A significant reduction in the number of various microorganisms in milk and dairy products was reported.…”

Nonthermal turbulent flow ultraviolet‐C (UV‐C) radiation processing for cheese whey‐brines purification

“…Inactivation models that accurately explain the reduction kinetics of foodborne pathogens in whey-brine may be very helpful at the stage of implementation of UV-C systems at the industrial level. Their use may also provide insight information about the effect of a number of factors, which should be considered for process optimisation (Possas et al 2018;Papademas et al 2021).…”

“…For E. coli, Staph. aureus, S. enteritidis and B. cereus, the corresponding UV-C dosages were: 0, 20,40,60,80,100,120,140,160,200,250, 300 and 400 J/L, whereas for L. innocua, samples were collected every 40 J/L for dosages between 0 and 500 J/L, instead of every 20 J/L due to higher resistance (Papademas et al 2021). The batches were prepared in duplicate for each bacterial strain.…”

“…Survival curves were plotted for each of the tested microorganisms. The inactivation kinetics of food pathogens were described by mathematical models and analysed by Microsoft Excel's (2010) add-in GInaFiT (version 1.7) (Geeraerd et al 2005) according to Papademas et al (2021). The fitting accuracy of each model for each tested pathogen was evaluated by calculating coefficient of determination (R 2 ) and root mean sum of squared error (RMSE).…”

“…Ultraviolet-C treatment can be performed under continuous or pulsed light where the liquid passes through a chamber and light photons are being absorbed by the product (Rodriguez-Gonzalez et al 2015). The UV-C spectrum has been proven to efficiently kill microorganisms in different liquids including different types of milk, while preserving nutritional and organoleptic characteristics (Dhahir et al 2021;Papademas et al 2021).…”