ISPAM September 6 2014 Meeting

Considerations for Field Sampling Romaine Lettuce for Microbiological Testing 1. Introduction (Scott Coates) In 2010, the Food Safety and Technology Council of United Fresh Produce Association developed a white paper known as Microbiological Testing of Fresh Produce that considered the use of microbiological sampling and testing procedures for fresh fruit and vegetable products. This paper provided much valuable information, but left open the question of how many samples to collect under what conditions. In 2012, the International Stakeholder Panel for Alternative Methods 1 (ISPAM) determined that it would fund a project to advance the cause of food safety in the produce area. With input from the produce industry, ISPAM determined two high priority areas: 1) standard methods for the detection of Salmonellae in leafy greens; and 2) standard sampling plans for field sampling of leafy greens, focusing on romaine lettuce as an example. Two working groups were created to consider the two priorities. The intention is to create a standard for methodology and a standard sampling plan that are complementary to one another. 1.1. Objective The objective of this paper is to build on the Microbiological Testing of Fresh Produce white paper by providing specific recommendations regarding the number and location of test samples to collect, and the best practices for collecting test samples to detect Salmonella from pre-harvest fields of romaine lettuce. 1.2. Scope of the paper This paper considers the current reasons for field sampling and industry production practices and controls of known hazards, the most likely sources of field contamination and recommended controls. Limitations because of product shelf-life such as inability to resample/retest and the need for rapid test method will are examined. The different types of field contamination patterns are also considered and recommendations are provided. This paper also reviews the ICMSF (ref) and Codex (ref) sampling plans and their assumptions. For the purposes of this start-up project, the working group, and therefore this paper, is focused specifically on the detection of Salmonella in pre-harvest fields of romaine lettuce. However, this project is expected to be the first in several projects in which the recommendations contained in this paper are considered and applied with appropriate refinements to additional pathogens, use with leafy greens and at other points in the food chain, such as after harvest but before processing. 1.3. Audience for the paper Food safety is a universal challenge, with several well-publicized produce contamination events occurring in both Europe and the United States in recent years. However, surely produce contamination events are occurring all around the world all of the time, just not as well detected,

1 ISPAM is funded and organized by the AOAC Research Institute, a subsidiary of AOAC INTERNTIONAL.