Non Technical Summary
Organic fresh produce products are at the risk of foodborne illnesses due to the lack of practices that can effectively decontaminate incident pathogens, and their shelf life is shortened due to loss of quality and/or fungi spoilage. Current commercial organic-compliant coatings can extend the shelf life but lack preservatives capable of inhibiting foodborne pathogens and fungi. Incorporating organic essential oils (EOs) in coatings may be the solution due to their proven effectiveness against both fungi and foodborne pathogens. The overall research goal of this project is to develop and implement organic compliant coatings with organic EOs to enhance postharvest quality and safety, while the overall extension goal is to train organic producers, packers, and technical service providers with innovative postharvest quality and safety knowledge and disseminate research findings. The research and extension activities will be guided by an advisory board. Two categories of coatings will be studied in Objective 1 for commercial organic coatings implementing EOs and novel acidic EO formulations, with an additional goal to make coatings wash removable. Six coating formulations will be studied in Objective 2 for reduction of foodborne pathogens on organic blueberries, apricots, peppers, tomatoes, and cantaloupe. Shelf-life and quality, including inhibition of decay, for organic produce coated with EOs will be evaluated in Objective 3, while consumer acceptability and economic analysis will be conducted in Objective 4. Extension activities in Objective 5 will include traditional print publications and in person workshops, as well as virtual webinars, a project website, YouTube channel, and X (formerly Twitter) account. The project will enhance post-harvest safety, shelf life, and quality that are critical to sustainable production of perishable organic fresh produce.

Classification

Knowledge Area (KA)	Subject of Investigation (SOI)	Field of Science (FOS)	Percent
712	5010	3020	35%
712	1111	1100	10%
712	1120	1100	10%
712	1460	1100	10%
712	1461	1100	10%
712	1420	1100	10%
501	5010	2000	15%

Knowledge Area
501 - New and Improved Food Processing Technologies; 712 - Protect Food from Contamination by Pathogenic Microorganisms, Parasites, and Naturally Occurring Toxins;

Subject Of Investigation
1111 - Apricot; 1120 - Blueberry; 1460 - Tomato; 1461 - Peppers; 1420 - Melons; 5010 - Food;

Field Of Science
3020 - Education; 1100 - Bacteriology; 2000 - Chemistry;

Goals / Objectives
The overall research goal of this OREI project is to develop and implement organic compliant coatings with organic essential oils (EOs) to enhance postharvest quality and safety, while the overall extension goal is to train organic producers, packers, and technical service providers with innovative postharvest quality and safety knowledge and disseminate research findings.The objectives are to(1) Formulate organic compliant essential oil coatings,(2) Reduce native fungi and foodborne human pathogens on organic produce with EO coatings,(3) Evaluate shelf-life and quality of coated organic fruits and vegetables,(4) Assess consumer acceptability and economic analysis of coating organic fruits and vegetables, and(5) Train organic producers, packers, and technical service providers and disseminate project findings.

Project Methods
In Objective 1, the activity of essential oils (EOs) will be analyzed for Salmonella cocktail, Listeria monocytogenes cocktail, and fungi isolated from diseased peach, blueberry, and cucumber tissues, with the goal of identifying EOs with synergistic antimicrobial activities to reduce their application levels in coatings. For bacterial pathogens, the analyses will include determining the minimum inhibitory concentration and minimum bactericidal concentration of individual EOs against pathogens at different pHs and the fractional inhibitory concentration index of antimicrobial combinations. For fungi, the mycelial growth inhibition will be determined for the chosen EO combinations identified for bacterial pathogens. The chosen EO combinations will be blended with organic vegetable oil to prepare emulsions using organic compliant emulsifiers, and the physical and antimicrobial properties of emulsions will be characterized. Physical and antimicrobial properties of films will be characterized for commercial coatings implemented with EOs and hydrocolloids, as well as novel coatings with acidic EO emulsions and hydrocolloids. Three independent replicates will be conducted, and the data will be subjected to ANOVA and Tukey's test for significant differences among treatments (P < 0.05).In Objective 2, six coatings to be chosen from Objective 1 will be applied on organic fresh produce of known production practices and same cultivar without undergoing postharvest unit operations. Blueberries, apricots, peppers, tomatoes, and cantaloupe will be inoculated with Salmonella or Listeria cocktail at a level of ~6.0 log CFU/piece of fruit (or 25-g blueberry), applied with coatings, and enumerated for surviving bacteria during storage at optimal storage conditions. The total yeast and fungi counts will also be enumerated during storage. Controls will include (1) fruits without inoculation but with antimicrobial coatings, (2) fruits inoculated with pathogens and treated with antimicrobial-free coatings, and (3) fruits coated with a commercial organic plant-based coating. Three samples will be evaluated for each replicate. All treatment combinations will be independently replicated three times, using a repeated measures experimental design to account for sampling over time. Experimental data will be subjected to ANOVA and Tukey's test as in Objective 1. In addition, because food contact surfaces and roller brushes are major concerns of pathogen cross-contamination in waxing facilities, the impact of new coatings on the survival of L. monocytogenes on food contact surfaces and their easiness for cleaning and sanitizing stainless steel and roller brushes made with different materials will be evaluated in the lab.In Objective 3, six antimicrobial coatings identified in Objective 1 will be applied to fruits, with an uncoated control and a commercial coating control. Four replicates of 20 fruit each (apricot, cantaloupe, pepper, and tomato) or 1 pint each (blueberry) will be studied per treatment. During storage at ideal temperatures for each commodity, fruit quality will be evaluated for color, firmness, soluble solids, titratable acidity, weight loss, fruit respiration, and fruit deterioration (damage and decay). These experiments will be repeated once. Statistical analysis of fruit quality attributes differences by treatment will be analyzed using ANOVA, and means will be separated using LSD. Consumer panels with 120 participants will be recruited to evaluate the effect of coatings on the samples for appearance liking, texture liking, flavor liking, and overall liking. Additionally, residual contents of coating materials on fresh produce will be determined before and after simulated consumer washing.In Objective 4, an online survey instrument will be developed to assess US customers' acceptance and perceptions of alternative organic fresh produce coatings, estimate potential premiums associated with alternative coating options, and identify customer segments and their motivations for accepting alternative fresh produce coatings on fruits and vegetables. The benefit-cost analysis will be used to determine the cost-effectiveness of the alternative organic-compliant coatings with organic EOs applied to fresh produce in this project.In Objective 5, a board of advisors composed of seven total individuals representing industry, governmental and regulatory agencies, trade organizations, and research will be engaged throughout the project to receive research updates from and provide feedback to the project team. Surveys will be developed to gather detailed insights to assess stakeholders' current practices, knowledge, skills, and attitudes, and the collected data will serve as a foundational resource to inform and guide extension activities. Knowledge and research findings from this project will be communicated to the produce industry over the entire project duration via both interactive engagement techniques and knowledge dissemination methods. These will include a dedicated project website providing comprehensive information of the project, project outputs, links to social media platforms (YouTube channel and X account), and a calendar of upcoming outreach events. Besides open-access peer-reviewed publications, project outputs include print materials or videos of extension and demonstration materials, webinars, workshops, and presentations at local, and national meetings. Based on stakeholder needs, a subset of resources will be translated into Spanish. All in-person events and live virtual events (e.g., webinars) will be evaluated by participants for satisfaction with the programming and their knowledge gain. Dr. George Chitiyo at Tennessee Tech University will be an independent external evaluator for this project.