This study determined and compared the inactivation rates of selected spoilage and pathogenic bacteria
in turbulent flowing, UV-C treated liquid endosperm (pH 5.80, 6.10 Brix) obtained from young (6e9
months) coconut drupes. Inoculation of test organisms significantly altered the UV-C absorbance and
transmittance of the liquid endosperm from 0.90 to 1.08 and 12.74%e8.39%, respectively. Inactivation
rates were expressed in terms of decimal reduction times (D values), defined as the exposure time
necessary to reduce the test organism by 90% or 1-log cycle. Furthermore, the DUV-C values, or the UV-C
dose necessary to reduce the organism by 90% were also determined. Results showed that while the D
and DUV-C values significantly varied among the spoilage organisms (D ¼ 2.93e5.60 s; DUV-C ¼ 7.63
e14.56 mJ/cm2), no significant differences were detected in the inactivation rates of the tested pathogens
(D ¼ 3.19e3.76 s; DUV-C ¼ 8.28e9.78 mJ/cm2). The inactivation parameters obtained in this work were
close to those previously established in non-turbulent, small volume coconut liquid endosperm, suggesting
that for this commodity, stirring may not be necessary to optimize microbial inactivation if UV-C
shall be applied to small volumes or thin films. The results established in this work may serve as baseline
information in the continuous optimization of UV-C process for coconut liquid endosperm and other
similar products, for the maintenance and control of food quality and safety