Evaluation of UV-C LEDs efficacy for microbial inactivation in tender coconut water.

Tender coconut water (TCW) as a food model was treated with UV to investigate the
efficacy of UV LEDs (255 nm) for non-thermal
processing by inactivating the possible
foodborne pathogens in TCW. TCW, when exposed to UV at a dose of 28 mJ/
cm2, significantly reduced Escherichia coli (ATCC 8739) to a 6.2 log CFU/ml. At a dose
of 21 mJ/cm2, Salmonella enterica (ATCC 13314) and Listeria monocytogenes (ATCC
19111) were reduced to a log of 6.3 and 5.6 CFU/ml, respectively. The physicochemical
properties and color measurement (L*, a*, and b*) of UV processed and unprocessed
samples show no significant changes. The metabolic profile of UV processed and
unprocessed TCW monitored with 1H-NMR
showed significant changes (p < .001)
particularly for major metabolites such as glucose (22.2 and 23.7 mM/100 μl) and
fructose (21.5 and 22.5 mM/100 μl). This study demonstrates the development of
UV LED-based
non-thermal
processing reactors for food processing.
Novelty impact statement: This manuscript details the studies related to the application
of UV-C
LEDs and their validation for beverage processing. UV-C
LEDs reduced
≥5 CFU/ml log of pathogens in tender coconut water (TCW). No significant changes
were observed in the physicochemical properties of the processed TCW. The use of
UV-C
LEDs can be an alternative approach for processing beverages.