Efficacy evaluation of a new water sanitizer for increasing the shelf life of Southern Australian King George Whiting and Tasmanian Atlantic Salmon fillets

Abstract

The bacterial species and specific spoilage organisms associated with the Southern Australian King George Whiting (KGW) and Tasmanian Atlantic Salmon (TAS), and the efficacy of a HOCl-containing water-based sanitization product (Electro-Chemically Activated Solution, by ECAS4) in extending the shelf life of KGW and TAS fillets were evaluated. Fillets were washed with an ECAS4 solution containing either 45 ppm or 150 ppm of free chlorine and bacterial species enumerated on selective and non-selective media, followed by identification of pure isolates by 16 S rRNA gene sequencing. The dominant spoilage microbiota in KGW and TAS fillets stored at 4 ± 1 °C were Pseudomonas spp. and Shewanella spp. At either concentration, ECAS4 significantly reduced total bacterial load and specific spoilage organisms on KGW and TAS fillets (approx. 1-2 log colony-forming units) during storage and significantly extended the shelf life of the fillets by 2 and 4 days, respectively. The significant increase in shelf life and quality of fillets was corroborated by raw and cooked sensory evaluation. ECAS4 sanitization could have a significant impact on the overall food industry, translating into health and economic benefits through reduction of food spoilage bacteria and potentially, foodborne pathogens without many of the disadvantages of currently approved biocides.

Decontamination of aerosolised bacteria from a pig farm environment using a pH neutral electrochemically activated solution (Ecas4 anolyte)

“…The initial bacterial reduction of 0.67 Log 10 CFU/m 3 after fogging for one hour is comparable to that achieved in our previous study, where Ecas4 anolyte at 45 ppm FAC wash sanitisation of fish fillets achieved reduction of 0.5 Log 10 [18]. Likewise, the 1.34 Log 10 CFU/m 3 reduction after two hours of fogging was superior to washing fish fillets with 150 ppm FAC (1.0 Log 10 ) [18].…”

“…The initial bacterial reduction of 0.67 Log 10 CFU/m 3 after fogging for one hour is comparable to that achieved in our previous study, where Ecas4 anolyte at 45 ppm FAC wash sanitisation of fish fillets achieved reduction of 0.5 Log 10 [18]. Likewise, the 1.34 Log 10 CFU/m 3 reduction after two hours of fogging was superior to washing fish fillets with 150 ppm FAC (1.0 Log 10 ) [18]. The different effectiveness observed between the two fish fillet wash experiments and the two fogging time points could be attributed to the presence of organic matter quenching the anolyte active components, since even Ecas4 with low FAC (0.5 ppm) was able to totally inactivate bacterial cells (5 Log 10 ) in the absence of organic material.…”

“…Advancements in the technique for generating ECAS with slightly acidic pH (5–6.5) has allowed the use of ECAS in sanitisation of vegetables with excellent efficacy [15–17]. Furthermore, ECAS with neutral pH having excellent oxidative properties and drastically reduced corrosiveness is increasingly being employed as a sanitiser in the food industry [18, 19] and as a wound dressing product [20]. ECAS is also employed in preventing or reducing rates of infection with MRSA in post-operative infections [21, 22] in place of broad-spectrum antibiotics whose use is limited due to the development of antibiotic resistance.…”

Application of Neutral Electrolyzed Water on pork chops and its impact on meat quality

“…Our results suggest that the presence of organic matter on pork limits the efficacy of NEW against Salmonella Typhi and mesophilic bacteria. In our study, NEW was applied using spray bottles however, different studies 42,46 showed better results when samples were dipped.…”

Comparative antibacterial activities of neutral electrolyzed oxidizing water and other chlorine-based sanitizers

“…Of the various types of EOW, neutral EOW has been considered the most promising as it contains predominantly HOCl, which is more effective than ClO − for microbial cell wall penetration and oxidative attack 12,17 . However, there are limited published applications of neutral EOW use in the irrigation and washing of fresh vegetables 18,19 or fruit 20,21 , with publications to date mainly focussing on its use in the seafood 22 and meat 17,23,24 industries. The use of Na-based salts rather than K for generation of the EOW might be of concern in the context of vegetable production, because of the potential problems associated with Na accumulation in soil, in contrast to the potential benefit of K supplementation for crop growth.…”