Continuous-flow UV-C processing of kale juice for the inactivation of E. coli and assessment of quality parameters

Jacob Pierscianowski; Vladimir Popović; Michael Biancaniello; Simon Bissonnette; Yan Zhu; Tatiana Koutchma

doi:10.1016/j.foodres.2020.110085

Continuous-flow UV-C processing of kale juice for the inactivation of E. coli and assessment of quality parameters

Food Res Int. 2021 Feb:140:110085. doi: 10.1016/j.foodres.2020.110085. Epub 2020 Dec 29.

Authors

Jacob Pierscianowski¹, Vladimir Popović², Michael Biancaniello³, Simon Bissonnette⁴, Yan Zhu⁵, Tatiana Koutchma⁶

Affiliations

¹ Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada.
² Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada. Electronic address: vladimir.popovic@canada.ca.
³ Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada. Electronic address: mbiancan@uoguelph.ca.
⁴ Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada; Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada. Electronic address: sbissonn@uoguelph.ca.
⁵ Department of Food Science, University of Guelph, Guelph, Ontario N1G 2W1, Canada. Electronic address: yzhu@uoguelph.ca.
⁶ Guelph Research and Development Center, Agriculture and Agri-Food Canada, Guelph, Ontario N1G 5C9, Canada. Electronic address: tatiana.koutchma@canada.ca.

PMID: 33648303
DOI: 10.1016/j.foodres.2020.110085

Abstract

Ultraviolet-C (UV-C) light is a non-thermal method for improving the safety and shelf-life of cold-pressed juices with minimal impact on quality and nutrition. Most previous studies have investigated fruit juices as opposed to particulate dense leafy green juices with very low UV transmittance (UVT). Pure kale juice is a common juice ingredient and represents the worst-case scenario in terms of low UVT green juices. This study validated the use of continuous benchtop UV-C treatment at 253.7 nm for 5-log reduction of non-pathogenic Escherichia coli P36 in kale juice. An average absorbed fluence of 108.3 mJ cm^-2 resulted in a 5.8 log reduction of E. coli P36. At a fluence comparable to that reported for commercial juice processing (74.0 mJ cm^-2), kale juice exhibited a decrease in absorption coefficient, while sedimentation, supernatant browning and pectin methylesterase activity increased with no effect on the chlorophyll content, colour, viscosity or antioxidant content.

Keywords: Average absorbed fluence; Bio dosimetry; Cold-pressed green juice; Delivered fluence; Incident fluence; Low UV transmittance (UVT); Ultraviolet-C (UV-C) processing.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Brassica*
Escherichia coli*
Food Microbiology
Fruit and Vegetable Juices
Ultraviolet Rays