Heat treatment and UV-C irradiation of lemon and melon juice (LMJ) blends were comparatively evaluated by
examining their impact on E. coli K12 (ATCC 25253) and their physicochemical properties, i.e., total soluble solids
(TSS), pH, titratable acidity (TA), color, turbidity and absorbance coefficient, both immediately after processing
and during 30 days of refrigerated storage. The newly formulated LMJ blend containing 12% (v/v) lemon juice
(pH 3.92 ± 0.01) scored the highest in the consumer acceptance test. Upon UV-C irradiation (2.461 J/mL) and
heat treatment (72 °C, 71 s), the E. coli K12 population in LMJ blend was reduced by N6 log10 CFU/mL. Principal
component analysis (PCA) and hierarchical cluster analyses (HCA) showed a clear discrimination among the
physicochemical properties of the control and the UV-C and heat-treated LMJ blends during storage, suggesting
that UV-C irradiation has a comparable effect onmicrobial stability at 4 °C and better quality preservation performance
than heat treatment.