Decontamination of Escherichia coli K12 NSR on Strawberries by Electrolyzed Oxidizing Water
Open Access
- Author:
- Fan, Wendy N
- Area of Honors:
- Biological Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Ali Demirci, Thesis Supervisor
Ali Demirci, Thesis Honors Advisor
Megan Nicole Marshall, Faculty Reader - Keywords:
- Strawberries;Electrolyzed oxidizing water; Decontamination;E. co
- Abstract:
- Food safety is extremely critical in order to ensure a customer’s well-being when consuming the target product. Fresh produce has an especially crucial focus due to the fact that they are picked freshly at a farm, so they could easily get contaminated from the soil during the harvesting process. Therefore, they must be handled and processed with extra precautions in place in order to not compromise customer safety and the overall quality. Electrolyzed oxidizing water, also known as EO water, has been used as a novel method to clean and decontaminate fresh produce. EO water is produced by the electrolysis of dilute sodium chloride solution, and it can kill microorganisms effectively. This project focuses on the inactivation of Escherichia coli K12 nalidixic acid and streptomycin sulfate (NSR) resistant strain on strawberries. From the results of preliminary studies and trials, the optimal condition to treat strawberries was determined to be 80% EO water at 32°C for 30 min in order to reduce the population of E. coli K12 NSR by 7-log. In addition, the quality study on colors of the strawberries before and after treatment was performed as well as the shelf life study of untreated and treated samples at both room (~22oC) and refrigerated (~4oC) temperatures. The quality test, measured by colorimeter, showed that there was no significant difference in the appearance of samples after the treatment. The shelf life study for the 7-day period at room temperature demonstrated that the treated strawberries formed less molds and less rotten surfaces compared to the untreated ones, and the samples stored in the refrigerator for 14 days showed that the quality of treated samples could stay excellent for two weeks without showing mold growths while the untreated samples had signs of mold growths. In conclusion, this study clearly demonstrated that EO water can be used to decontaminate strawberries to assure safety and extend shelf-life.