Performing Department
(N/A)
Non Technical Summary
Postharvest water is any water that contacts fresh fruits and vegetables or food contact surfaces during or after harvest. Postharvest water use may be a necessary part of produce production, but it is also a potential source of microbial cross-contamination since hazards introduced into the water (e.g., soil adhering to the produce) can led to widespread pathogen proliferation. While some processors use single-pass systems that do not recycle the water, most postharvest processes recirculate used water to conserve water and energy. Since water reuse increases the potential microbiological risks associated with the accumulation of microorganisms, determining a water change schedule for recirculated water that safeguards produce safety as well as optimizes water consumption will assist with maximizing resources (e.g., water, energy). While the produce industry places heavy emphasis on establishing water-change schedules and maintaining sanitizer concentrations to minimize the potential for contamination of produce, validation studies conducted on commercial postharvest water systems are lacking. This multistate project intends to develop and confirm strategies for on-site validation of commercial postharvest water systems aimed at optimizing produce safety and water consumption for the produce industry.Objective 1: Develop a strategy for on-site validation of commercial flume systems for produce safety and water consumption optimization.Objective 2: Confirm validation strategy by conducting on-site assessments of physicochemical and microbiological water quality throughout flume systems within commercial tree fruit packing operations.Objective 3: Develop extension documents, guidance documents, and hands-on field day activities on the key criteria needed to effectively validate in-process flume systems.
Animal Health Component
0%
Research Effort Categories
Basic
0%
Applied
100%
Developmental
0%
Goals / Objectives
This multistate project intends to develop and confirm strategies for on-site validation of commercial postharvest water systems aimed at optimizing produce safety and water consumption for the produce industry.Objective 1: Develop a strategy for on-site validation of commercial flume systems for produce safety The project team, alongside input from industry personnel, will aggregate scientific and industry-relevant knowledge related to the safe operation of recirculated postharvest washing systems. From this, a validation protocol will be developed incorporating current industry relevant conditions used in postharvest water management.Objective 2: Confirm validation strategy by conducting on-site assessments of physicochemicaland microbiological water quality throughout commercial postharvest water systems The validation strategy developed in objective 1 will be verified within multiple commercial tree fruit packing operations in Washington and Virginia.Objective 3: Train growers on key criteria needed to effectively manage and validate in-processpostharvest water systems Extension publications, guidance documents, and hands-on field day activities will be developed and delivered to relevant personnel in the produce industry on approaches for validating their postharvest water systems to safeguard food safety while optimizing the use of resources. Outputs will be shared with
Project Methods
Objective 1:During year 1 meetings, the project team will have discussions with stakeholders across the US in order to determine current industry-relevant measurements and values used in postharvest water management that need to be considered as key criteria in the development of validation methodology.Current scientific and industry-relevant knowledge related to the safe operation of recirculated postharvest washing systems will be aggregated to determine current industry- relevant conditions that are effective at managing postharvest water. From this, the project team will meet to develop a working protocol to be used in a commercial setting to validate postharvest water management incorporating effective conditions identified during knowledge collection.Objective 2:For objective 2, the validation protocol will be verified in commercial operations in Virginia and Washington, where processors have agreed to serve cooperators and allow their postharvest systems to be used for data collection.Three commercial tree-fruit packing houses in Washington and one in Virginia will used at different time points over the packing season to verify the postharvest water management protocol developed in objective 1. Water samples will be collected from dump tanks and flume systems when a new batch of water is added and at intervals throughout the entirety of the production with the batch of recirculated water. Bacterial counts (total coliforms Generic E. coli, yeast/mold) will be enumerated from water samples and produce at numerous different locations in the water system. Water quality will be analyzed for additional factors including turbidity, oxidation-reduction potential (ORP), chemical oxygen demand, conductivity, pH, etc.Sample collection: Sodium thiosulphate or sodium metabisulfite will be utilized to neutralize any sanitizer activity once the water is collected. All samples will be stored on ice until transport to the laboratory, and all samples will be run within 24 hours of sample collection.Microbial Enumeration: Total coliform and generic E. coli concentrations will be enumerated following standard techniques using Coliert/Quanti-Tray 2000 (IDEXX) with appropriate dilutions made to facilitate enumeration. Yeast and mold Petri film will be used, with appropriate dilutions.Water Quality: Real-time water quality parameters will be measured in triplicate at each of the time intervals used for microbial enumeration. Temperature, pH, oxidation-reduction potential (ORP), total dissolved solids (TDS), and turbidity will be measured using portable meters and probes. Residual sanitizer levels in water (e.g., free chlorine) will be measured using a colorimetric titration method (e.g., N-diethyl-p-phenylenediamine sulfate. If needed, to test higher concentrations, dilutions will be performed using distilled water.Objective 3:Extension documents outlining pertinent aspects of managing postharvest water systems for the industry will be created to address knowledge gaps. Topics of interest for extension documentation include "How to Read the Label of an Antimicrobial Product for Postharvest Water Usage" and "How to Determine a Postharvest Water Change Schedule for Your Operation".In order to provide the produce industry with resources to manage water in their operation, a guidance document and best management practices document will be developed. The guidance document will outline how producers can validate and interpret the validation data for their operations, based on the methodology the project team used in objective 2. The best management practices document will describe ways producers can manage their postharvest water based on the key takeaways from data analysis conducted by the project team. Hands-on activities will be developed and piloted a field days and workshops in Washington State. Educational recourses for the hands-on activities will be created and distributed to extension personnel and educators around the US to use.?