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ARS Home » Pacific West Area » Albany, California » Western Regional Research Center » Produce Safety and Microbiology Research » Research » Publications at this Location » Publication #422943
Research Project: Elucidating the Factors that Determine the Ecology of Human Pathogens in Foods

Location: Produce Safety and Microbiology Research

Title: High-throughput robotic workflows and data-driven analysis for enhanced chemical treatment of agricultural waters in California

Author
item Quintela, Irwin
item KANESHIRO, DEVIN - Volunteer
item NIGUDKAR, ATHARVA - Volunteer
item KITAZUMI, AI - Texas Tech University
item DE LOS REYES, BENILDO - Texas Tech University
item Wu, Vivian

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/5/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary: N/A

Technical Abstract: Agricultural (Ag) water quality is a predominant factor of produce safety; thus, efficacious Ag water treatments are paramount. In response to reoccurring outbreaks in leafy greens, the US FDA/EPA established a sanitizer efficacy protocol on Ag waters. However, the steps outlined are laborious and require large media and reagent volumes to conduct the entire procedure. This study aimed to adopt the current FDA/EPA recommended guidelines for high-throughput robotic workflows and data-driven analysis for improved antimicrobial treatment of Ag waters in the state of California. Treatment volumes of MilliQ (MQ) and freshly collected Ag waters from various sources were adjusted to the desired pH levels (6.5 and 8.4) before adding test organism panels [Shiga toxin-producing E. coli (STEC) or Salmonella spp.]. Test substances – sodium hypochlorite (NaClO) or aqueous peracetic acid (PAA) within 3 – 6 ppm range were prepared on treatment volumes and left for the required parameters (5 min, 12C or 42C). All samples were neutralized with sodium metabisulfite (Na2S2O5) post treatment and quantified using agar plates. In parallel, similar setups were prepared on 2 mL 96-well plates using a stand-alone walk away robotic system with chromagen. Post-treatment Most Probable Number (MPN) values were determined based on color reactions analyzed by ImageJ and Python programs. Results showed a > 3 log CFU/mL reduction of test organisms using the sanitizers. Notably, a higher final concentration of PAA (6 ppm) was needed to achieve 3 log/mL reduction of Salmonella spp. in Ag water, while NaClO remained significantly effective at 4 ppm in both MQ and Ag water samples (P < 0.01). Similar reduction levels (> 3 log CFU/mL) were achieved using the robotic system showing an average MPN values < 10 post treatment. This study has developed a solution technology with a streamlined sustainable systems approach that meets the stipulations of the FDA/EPA recommended guidelines for faster and enhanced chemical treatment of Ag waters that would benefit the agricultural produce processing industry and irrigation water facilities.