Summary
The purpose of this proposed research project is to determine the occurrence of microbial pathogens on fresh market apples and identify practices industry participants are using to mitigate these pathogens. Intertox will work closely with the Washington Tree Fruit Research Commission and its partners to identify available datasets of microbial pathogen levels, ensuring the confidentiality of any private data, and to develop datasets if needed. Data will be evaluated for their quality and relevance, and compiled into a database. Once complete, this dataset will be used to derive statistics on baseline microbial populations. Finally, the effectiveness of mitigation practices on reducing pathogen levels will be examined.
Technical Abstract
The objective of the proposed research project is to identify pathogens of concern for fresh market apples, determine their occurrence patterns and then research and document health-protective practices already in place. The project will cover fresh market apples starting at the packinghouse and continuing through storage and transportation. Intertox will work closely with the Washington Tree Fruit Research Commission (WTFRC) and their partners to identify available datasets of microbial pathogen levels on fresh market apples and to ensure the confidentiality of any private data. Data will be evaluated for quality and relevance and will be compiled into a new database. Upon completion, this dataset will be used to derive statistics on baseline microbial levels. Depending on data availability, Intertox will analyze the data for patterns and trends (e.g. seasonal variations, production practices, proximity to sources, etc.). If limited data is available, Intertox will work with the WTFRC and others to collect information through surveys and other sources. After completing the dataset, Intertox proposes examining and documenting current mitigation practices. The fact that there have been no incidences of foodborne illness related to fresh market apples supports the premise that current good agricultural and handling practices used in the fresh market apple industry are highly effective in mitigating microbial contamination risk. Intertox would like to verify this assumption by examining and documenting current mitigation practices and their ability to reduce the potential for microbial contamination. Project results will be presented to stakeholders at industry meetings as requested by the WTFRC.
Research Objectives
1. Meet with The Pacific Northwest Food Safety Executive Committee to gain an understanding of the potential apple microbial issues, practices used and current data availability.
2. Solicit industry support for scope and participation in the project during the Washington State’s Horticultural Association’s annual meeting in December 2010.
3. Develop a questionnaire for distribution to packing houses to obtain information on the food safety programs and efforts contributing to the mitigation of microbial pathogens currently in place.
4. Collect industry data.
5. Prepare database and evaluate data quality. 6. Prepare a baseline report of microbial pathogens, food safety programs and current mitigation practices and their ability to reduce microbial pathogens.
Findings & Recommendations
- Thirty‐two companies, representing 55% of all apple packing companies (conventional and organic) in Washington, completed surveys. Thirty‐four percent of the survey respondents categorized their operations as small (<1.25 million boxes), 50% as medium (1.26 – 3.75 million boxes), and 16% as large (>3.76 million boxes).
-94% of survey respondents reported that they test the water used in the packing line regularly for microbial load. The organisms most often tested for are fecal coliform and generic E. coli. Target organisms other than fecal coliform and generic E. coli included total coliform, Listeria, and Salmonella.
- Seventy‐eight percent of the survey respondents reported using environmental testing to check microbial levels at their packing facility including testing for fecal coliform, generic E. coli, E. coli O157:H7, total coliform, Listeria spp., and Salmonella.
- Of the 32 survey respondents, nine reported they conduct microbiological testing of their apples before shipping to customers. Summary of Data Findings: Based on the test results, packing houses conduct microbiological testing of water, various surfaces in the packing house, and occasionally, apples at various points in the packing line.
- Water testing is more prevalent than other types of testing. 516 water tests were reported for the period of 2005 through 2010 with 60% tested for total coliform, 23% for fecal coliform, and 16% for generic E. coli. Of the water samples that were tested for fecal coliform and generic E. coli, 84% and 10 72%, respectively, had levels less than 2 MPN/100 mL. Colilert® water test results (n = 310) were most often negative for both total coliform and E. coli (86%), with 13% positive for total coliform but negative for E. coli, and only 1% positive for both total coliform and generic E. coli.
- Environmental testing has generally increased since 2006. Companies tested environmental surfaces in their packing houses for generic E. coli (39%) and Listeria spp. (30%) more than they did for Salmonella (17%) or total coliform (14%).
- From 2009 to 2010, with the exception of Salmonella testing, environmental testing for all target organisms increased substantially. From 2005 to 2010, the number of Z5sampling locations increased as well. Positive results were reported for total coliform, generic E. coli, and Listeria spp. E. coli O157:H7 and Salmonella were not detected in the environmental tests.
- Product testing has decreased since 2008. Of the 565 product tests conducted between 2005 and 2010, slightly less than one percent was positive.