Summary of Awards to Date

Control of Salmonella and Listeria monocytogenes on peaches through spray-bar brush bed sanitizer intervention

Date

Jan. 1, 2023 - Dec. 31, 2024

Amount Awarded

$398,154.00

Investigator

Meijun Zhu, Ph.D.
Washington State University

Resources
Summary

Recent multistate Salmonella and Listeria monocytogenes outbreaks linked to peach and stone fruit consumption posed serious health risks to consumers and caused huge economic loss to the stone fruit industry. These outbreaks also indicate that foodborne pathogens can survive and persist on stone fruits during production, processing, and subsequent handling, highlighting the need for controlling these pathogens in peaches and other stone fruits. Although sanitizer intervention has been used during peach or stone fruit processing, there is a general lack of knowledge on the efficacy of current antimicrobial interventions under commercial packing conditions for the reduction of pathogens on fruits. This proposal aims to assess critical operating parameters for commercially used sanitizers against Salmonella, L. monocytogenes, and their non-pathogenic surrogate and further verify this efficacy on multiple commercial stone fruit packing lines. The proposed project will develop information for stone fruit producers on the practical efficacy of antimicrobial interventions under commercial packing conditions. The findings of this study will also guide the selection of sanitizer spray treatments and aid in the design and implementation of preventive controls and postharvest interventions for stone fruits.

Technical Abstract

Stone fruits such as peaches are an important global commodity. California is the leading state of peach production, producing ~76% of peaches in the United States. Recent multistate Salmonella and Listeria monocytogenes outbreaks linked to peach and stone fruit consumption posed serious health risks to consumers and caused huge economic loss to the stone fruit industry. These outbreaks also indicate that foodborne pathogens can survive and persist on stone fruits during production, processing, and subsequent handling. This is of particular concern with fresh stone fruits like peaches that have no kill step before consumption, highlighting the critical need for preventive control of foodborne pathogens in peach and other stone fruits. Although the addition of sanitizing agents in peach spray wash water is a standard industry practice, little is known about the practical efficacy of current antimicrobial interventions under commercial packing conditions for the reduction of pathogens on fruits. The overall goal of the proposed studies is to comparatively assess and validate critical operating parameters for commercially used practical and Generally Recognized as Safe (GRAS) sanitizers against Salmonella, L. monocytogenes, and their surrogate and to further verify this efficacy on multiple commercial peach packing lines. We will pursue two specific objectives. 1) Validate the efficacies of selected sanitizers against Salmonella and L. monocytogenes on peaches; 2) Verify the selected sanitizer interventions in the representative commercial peach packing lines in California. The proposed studies are expected to generate immediately actionable information for the stone fruit industry. The findings of this study will provide the industry with science-based guidance on optimal process parameters and standard operating procedures. The outcomes will further provide a framework for validated process controls, verification of standard operating procedures, and monitoring protocols accessible to the stone fruit industry to support compliance with FSMA Preventive Controls requirements.