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

Abstract

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.