Controlling Salmonella on eggs using probiotics and postbiotics.

Project Overview

Project Type: Graduate Student
Funds awarded in 2022: $15,000.00
Projected End Date: 07/31/2024
Grant Recipient: University of Connecticut
Region: Northeast
State: Connecticut
Graduate Student:
Faculty Advisor:
Mary Anne Amalaradjou
University of Connecticut


  • Animal Products: eggs


  • Crop Production: food product quality/safety

    Proposal abstract:

    Salmonella Enteritidis (SE) is a leading foodborne pathogen in the US, with many outbreaks traced back to eggs. Although SE can be vertically transmitted, once laid there are multiple routes by which the pathogen can contaminate eggs. Therefore, decontamination of eggs is critical to promote its food safety. One of the simplest on-farm approaches to reduce egg contamination is the prompt collection and refrigeration of eggs. Besides refrigeration, eggs are routinely washed in disinfectant containing water prior to shipping. Despite these strategies, there is a lack of decline in Salmonella outbreaks. Therefore, poultry producers are looking for effective strategies to promote egg safety. In this regard, probiotics are commonly used in poultry production for growth promotion and pre-harvest control of SE. In addition to probiotics, postbiotics (probiotic metabolites) also provide a novel antimicrobial alternative to the control of foodborne pathogens. However, to our knowledge, neither probiotics nor postbiotics have been studied for their ability to control SE on eggs. Hence, we propose the incorporation of probiotics and postbiotics in wash water to reduce SE contamination on eggs either as a conventional dip or spray application. We expect that results of the study will help identify different antimicrobial regimens and application modalities that can be tailored to specific production needs to promote the egg industry and public health. Overall, it is anticipated that these interventions could be used as part of a multi-hurdle on-farm approach to provide sustained antimicrobial activity against foodborne pathogens on eggs.

    Project objectives from proposal:

    The overall objective of the proposed study is to determine the antimicrobial efficacy of select probiotics and postbiotics as an egg wash for controlling SE on eggs. As an alternative to washing eggs using the conventional dip method, our study will also investigate the spray application of probiotics/postbiotics to improve egg safety. Egg washing is a method to reduce pathogen contamination on eggs. However, specific requirements such as warm wash water and warm sanitizing rinse are required according to the USDA egg washing standards. In this regard, probiotic and postbiotic spray application avoids increases in egg temperature that can happen when using warm washes. This treatment would also be a more economical processing method since it would eliminate the cost to heat the wash water or decontaminate the wash water prior to its disposal. Further, probiotic/postbiotic spray has the potential to be an environmentally friendly option and can help reduce water usage on the farm19. Specifically, in this study, we will use an electrostatic spray applicator to ensure uniform product deposition on the egg surface20. Further, to ensure sustained probiotic viability in significant numbers, probiotic wash solutions will be prepared incorporating protectants namely gum acacia and inulin.

    Our specific objectives for the proposed study are as follows:

    1. To determine the efficacy of incorporating probiotics in wash water to control SE on shell eggs when applied as an electrostatic spray and conventional dip solution.
    2. To determine the efficacy of incorporating postbiotics in wash water to control SE on shell eggs when applied as an electrostatic spray and conventional dip solution.
    3. To determine the effect of the different treatments and treatment modalities on egg quality and cuticle coverage.
    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.