Inactivation of E. coli in kale juice by continuous-flow UV-C

A study by researchers from Guelph Research and Development Center, Agriculture and Agri-Food Canada, published in Food Research International (volume 140, February 2021), investigated the inactivation of E. coli by Ultraviolet-C (UV-C) light and its impact of continuous UV-C on the product quality.  UV-C light is a non-thermal method for inactivating bacteria and improving the shelf-life of cold-pressed juices with minimal impact on quality and nutrition. Pure kale juice is a common juice ingredient and represents the worst-case scenario for low UVT green juices. The study showed a 5.8-log reduction of non-pathogenic Escherichia coli due to an average absorbed fluence of 108.3 mJ cm−2. At a fluence comparable to that reported for commercial juice processing (74.0 mJ cm−2), kale juice exhibited a decreased absorption coefficient. The treatment caused the sedimentation, supernatant browning, and pectin methylesterase activity to increase with no effect on the chlorophyll content, color, viscosity, or antioxidant content.  @ https://www.sciencedirect.com/science/article/pii/S0963996920311108?dgcid=author