A Microbial Comparison of Ready-to-Eat (RTE) Conventional and Organic Spinach and Arugula

As the organic food market continues to produce significant sales revenue, growers and retailers are increasingly interested in investing in this market. Since leafy greens may be prepared without a kill step, maintaining proper food safety standards is vital regardless of the production system. To evaluate the efficacy of growing systems, a general microbial comparison was made between products that were grown and processed either organically or conventionally. Packaged, triple washed spinach and arugula displayed in chill cases were purchased from local retail markets. Packages were chosen with code dates remaining of approximately 1 week, and analyzed for microbial content on the same day. The samples were tested for aerobic mesophilic microorganisms, total coliforms, and Escherichia coli. The results showed that the mean aerobic microorganism count and standard deviation for conventional and organic leafy greens were 6.89 +/- 0.13 and 7.27 +/- 0.13 log(10) CFU/g, respectively; levels that were not significantly different. Additionally, no significant differences were found for percent positive samples for E. coli and total coliforms between each production method. This study investigated the long term trend in these produce items over a multiple month time period to determine general microbial incidence of the two growing and handling systems.