Summary of Awards to Date

Apple growing and packing microbial risk factors and their potential to lead to foodborne disease outbreaks.


Jan. 1, 2012 - Dec. 31, 2013

Award Number


Amount Awarded



Richard Pleus, Ph.D.
Intertox, Inc.


In view of the passing of the Food Safety Modernization Act, the food industry, including the specialty crop industry, is under increased pressure to demonstrate the safety of their products. Although apples have a reputation with consumers as being a safe commodity, the fresh market apple industry would like to deepen its understanding of why their commodity is safe and how it can be made safer if needed. To this end, our proposal seeks to provide the industry with a microbiological risk assessment for apples. We will use data collected by the apple industry in their food safety programs to examine the potential occurrence of pathogens on apples in the production and packing environments. This data, along with data on apple consumption, will be used to estimate the exposure of American consumers to potentially contaminated apples. The risk assessment will conclude with an estimate of the risk of becoming ill from consuming apples potentially contaminated with pathogens. Information about specific areas of risk will allow apple growers and packers to adjust their practices and allocate their food safety resources more effectively while enhancing the safety of fresh market apples for consumers.

Technical Abstract

This proposal seeks to examine fresh market apple production and packing house data for microbiological pathogens of concern and to use these data to determine the potential for pathogen levels to result in illness.  Using pathogen test data collected from production and packing operations, we will describe the significance of various production and packing house processes relative to the potential occurrence of pathogens of concern.  To estimate the risk of illness associated with consuming apples contaminated with pathogens, we will develop a risk assessment that estimates the probability of exposure to potentially contaminated apples and then characterizes the nature and likelihood of an adverse health effect associated with the estimated exposure levels (Lammerding, 2000). 

To address the research priorities presented in the Request for Proposals, this proposal plans to apply quantitative risk assessment techniques determine the likelihood of foodborne illness from consumption of fresh market apples using data from industry, the Centers for Disease Control (CDC), and other published research related to particular pathogens.  To address the uncertainty in the data used in the risk assessment, we will develop the model using probabilistic methods to quantitatively characterize the uncertainty and variability in estimates of exposure or risk.  Intertox is currently working with the Washington apple industry to gather data on baseline levels of microbial pathogens on fresh market apples in packing houses, as well as measures being used to mitigate these levels.  This proposal suggests using similar methods to collect grower data in order to extend the risk assessment to production operations.  The risk assessment will be conducted and written in accordance with the four components of the generally-accepted risk assessment framework:  Hazard identification, exposure assessment, dose-response assessment (also known as hazard characterization), and risk characterization. 

The proposal consists of five primary objectives: grower data collection, correlation of process pathogen data to end product data, development of a risk assessment model customized for apple packing operations to estimate the risk of foodborne illness, preparation of a written risk assessment document detailing the results, and advisory panel review and oversight. Information about specific areas of risk will allow apple packing businesses to adjust their practices and/or allocate resources to reduce risk more effectively.  In addition, regulatory agencies are expanding the use of commodity-specific risk assessments to focus limited resources on commodities according to associated food safety risks. 

The result of this project will be an assessment of the microbial risks associated with apple production and packing operations and a methodology for evaluating other tree fruit and/or additional industry practices as further data become available.  When completed, the risk assessment will provide apple production and packing operations with information about particular areas of their process that will enable them to focus their food safety efforts and determine the appropriateness of current practices in these areas.   It will also provide the industry, regulatory agencies, and consumers with an overview of the risk to public health from consumption of fresh market apples.