Submitted by Dr David OgunniyiProfessor Enzo Lombi & Dr Cathy Dandie

Senior Research Fellow, Dean: Research and Innovation & Research Assistant

Foodborne diseases and illnesses due to microbial spoilage of fresh produce caused by foodborne pathogens are a widespread and growing public health and economic concern worldwide. Consequently, there are renewed calls globally for the development of safe, effective, inexpensive, easy to deploy and environmentally-friendly solutions to substantially reduce or eliminate illnesses and deaths linked to these pathogens.

To address this need, our experts at FII and other UniSA collaborators are involved in a current Hort Innovation project examining the safety and efficacy of a pH-neutral electrolysed oxidising (EO) water produced by a South Australian company, Ecas4 Australia, to improve the overall quality and value of minimally-processed foods such as lettuce, spinach, broccoli, tomato, capsicum and melons. 

We are comparing the efficacy of different doses and dosage regimes of EO water with those of industry standards such as sodium hypochlorite (through irrigation) in reducing/eliminating microbial contamination of these foods using quantitative culture and culture-independent molecular-based methods as well as shelf-life assessments.The molecular biology methods include quantitative culture, DNA and RNA analyses by qualitative and quantitative PCR, digital droplet PCR, metabolic activity measurements (using biosensors) and next-generation sequencing (16S rRNA gene metagenomics).

In addition, we are performing a detailed analysis of the mechanism of action and chemical composition (HOCl, OCl, Cl2) of the various EO water delivery (liquid, fog, ice, gel, booster) systems, examining if any of these can eliminate biofilms and/or prevent the viable but nonculturable microbial state, and assessing the potential of the EO water to generate disinfection by-products.

The effects of EO water application on the physico-chemical parameters and microbial composition of different soil types are also being assessed. The results will provide recommendations for technology adoption by Industry, which should translate into health and economic benefit through reduction and/or eradication of food spoilage bacteria and job creation. It will also fortify engagement with industry and other stakeholders leading to translation of research outcomes into community benefit.

Associated links

https://apps.who.int/iris/bitstream/handle/10665/199350/9789241565165_eng.pdf;jsessionid=F91E1ECA8BA643F8316E903B6A34F6C6?sequence=1

http://www.foodstandards.gov.au/industry/foodrecalls/recalls/Pages/Woolworths-loose-leaf-lettuce.aspx

http://www.foodauthority.nsw.gov.au/_Documents/foodsafetyandyou/listeria_outbreak_investigation.pdf

https://www.foodstandards.gov.au/code/proposals/documents/P1015%20Horticulture%20PPPS%201CFS%20SD2%20Illness%20review.pdf

Zhu, Q., Gooneratne, R. and Hussain, M.A. (2017) Listeria monocytogenes in fresh produce: outbreaks, prevalence and contamination Levels. Foods 6(3), 21.