Purpose: This project uses plasma activated water (PAW) and plasma treated acid electrolyzed water (PAEW) as novel and effective sanitizers for egg washing, to reduce microbial load with minimal loss of egg quality.
Methods: PAW and PAEW were generated by exposing distilled water or acid electrolyzed water to a cold atmospheric pressure plasma jet. The effectiveness of PAW, PAEW, and quaternary ammonium (QA) against a non-pathogenic Salmonella spp. surrogate (Enterobacter aerogenes) were evaluated in a planktonic-cell system. The novel sanitizers were, also, used to sanitize farm eggs, which were stained to detect cuticle loss by colorimetric analysis.
Results: Planktonic-cell experiments with distilled water caused reduction of 0.17±0.12 log CFU/ml from initial concentration of 9.21±0.06 log CFU/ml. Treatment with equal volumes of PAW, PAEW or QA resulted in a bacterial concentration below the detection limit (3.17 log CFU/ml). There was a statistically significant difference in microbial reduction between PAW/PAEW and distilled water (p-value <0.05), but no difference between PAW/PAEW and QA. A statistically significant difference was, also, noted by colorimetric analysis with respect to unsanitized eggs, between farm eggs treated with PAW/PAEW and store bought eggs. The DE-values observed were 13.98±5.51, 13.91±7.32, and 30.21±8.65 for PAW, PAEW, and industrially sanitized eggs, respectively. A lower DE-value suggested higher cuticle coverage.
Significance: PAW and PAEW appear to show promise for use in an egg washing process to replace current chemical sanitizers (QA) with minimal cuticle loss. Future experiments on eggs and with Salmonella spp. are needed.