Ultraviolet-C light inactivation of Penicillium expansum on fruit surfaces

Ultraviolet-C light inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on organic fruit surfaces

“…The less than 1 mm penetration depth for UV-C can affect the viability of microbial cells as reported on apples (Manzocco et al, 2011). This agrees with results from Syamaladevi et al (2015) who observed that higher UV-C doses were required for Penicillin expansum on rough fruit surfaces such as strawberries and raspberries compared to apples and cherries.…”

“…The higher E 90 on raspberry (E. coli O157:H7) and cantaloupe (L. monocytogenes) may be due to the large number of trichomes and drupelets on raspberry surfaces (Syamaladevi et al, 2015) and the dense netting on cantaloupe surfaces (Annous et al, 2005). We found that UV-C light was effective only on exposed surfaces and rough surfaces shadow microbial cells, impairing the germicidal effect of UV-C light (Manzocco et al, 2011;Syamaladevi et al, 2013).…”

“…The surface roughness of fruits was determined as described by Syamaladevi et al (2015). Briefly, a 10 × 10 mm section of apples, pears and cantaloupes was removed, and the flesh was cut back tõ 2-3 mm from the skin.…”

“…This hinders the removal of pathogens from fruit surfaces during a variety of treatments (Liao and Sapers, 2000;Wang et al, 2008) and alters the susceptibility of microbes to decontamination treatment (Burnett et al, 2000). In general, higher UV-C doses are required to reduce microorganisms on fruit surfaces that are rougher, have lower spreading coefficients, or that contain trichomes (Syamaladevi et al, 2014;Syamaladevi et al, 2015).…”

“…Our previous research found that fruit surface characteristics influenced the UV-C inactivation kinetics of blue molds (Syamaladevi et al, 2013 and2015). However, further research is needed to determine the influence of fruit surface morphology on UV-C inactivation of foodborne pathogens.…”