Authors: Paige Beuhler and Ines Hanrahan, March 2024
For 2024, the Washington Tree Fruit Research Commission approved $420,012 to help fund four (4) new Apple Horticulture and Postharvest projects.
2024 New Apple Horticulture and Postharvest Project Details
Project Title: Utilizing Far-UV Technology for Decay and Microbial Safety Management
Organization(s): Washington State University, Washington Tree Fruit Research Commission
Principal Investigator(s): Zhu, M.; Mendoza, M.
Total Funding Amount for All Years: $315,281
Length: 3 Years
The interest in Far-Ultraviolet (UV) systems within Washington apple packing lines has surged recently, but their potential benefits have not been scientifically verified. UV light, known for its germicidal properties, typically relies on mercury vapor lamps. The overall goal of this study is to conduct a comprehensive assessment of the efficacy of Far-UV technology, either independently or in conjunction with Peroxyacetic Acid (PAA) or chlorine, in controlling L. monocytogenes and decay organisms on apples of the selected varieties within the pilot-scale processing facility. The effectiveness will be further verified in two commercial packing lines. In direct response to industry feedback and to address these commercially critical questions, the team will pursue three specific objectives:
- Examine the effectiveness of Far-UV technology against Listeria and decay organisms on apples in the pilot packing line.
- Evaluate the synergistic effect of Far-UV in combination with commonly used commercial sanitizers against Listeria and decay organisms on apples in the pilot packing line.
- Verify the efficacy of selected Far-UV alone and in combination with PAA or chlorine interventions on two commercial apple packing lines.
Project Title: Optimizing the Lifespan of Chlorinated Dump Tank Water via Modeling
Organization(s): Washington State University, Washington Tree Fruit Research Commission
Principal Investigator(s): Zhu, M.; Mendoza, M.
Total Funding Amount for All Years: $309,859
Length: 3 Years
In the realm of commercial apple processing, the recycling and recirculation of water within dump tank systems often result in elevated organic matter levels, presenting a potential risk for microbial cross-contamination. Consequently, strategic management of postharvest dump tank water has been increasingly critical, aiming to minimize wastewater discharge and extend the lifespan of process water without compromising pathogen control and decay prevention. Chlorine is extensively used in the dump tank water for this purpose. However, its effectiveness is subject to variation based on organic load, and there is limited understanding of its dynamics during dump tank practice.
The overall goal of this study is to develop and optimize mathematical models that can predict changes in water parameters and sanitizer effectiveness during recirculated wash conditions. Initially, model parameters will be determined through data collected from interventions using a pilot-scale dump tank. The models’ accuracy will then be validated and optimized using commercial dump tank water, with or without water filtration systems. In direct response to industry input and to address these commercially critical questions, the team will pursue three specific objectives.
- Develop mathematical models to assess the impact of critical processing parameters on chlorine efficacy in controlling L. monocytogenes during dump tank practices.
- Evaluate and model the efficacy of chlorine against decay organisms during dump tank practices.
- Monitor the dynamic changes in physicochemical and microbial parameters of processing water in commercial dump tanks, testing the accuracy of the developed models and optimizing them.
Project Title: Ionized Hydrogen Peroxide Mist and UV-LEDs for Apple Decay Control
Organization(s): Oregon State University, Washington State University
Principal Investigator(s): Wang, Q.; Waite-Cusic, J.; KC, A.; Murphy, C.
Total Funding Amount for All Years: $250,905
Length: 3 Years
Fresh apples are vulnerable to microbial contamination, leading to rapid spoilage, reduced shelf life, and food safety concerns. Furthermore, foodborne pathogens, such as Listeria monocytogenes, associated with postharvest cross-contamination and cold storage facilities, pose significant food safety risks. The apple industry relies on basic management practices, mostly fungicides and sanitizers, to minimize contamination and product loss. Organic facilities have fewer chemical options for managing these risks. As the industry anticipates future pressures, including labor management, inflation, climate change, and wildfires, the urgency to minimize postharvest product loss is critical. Consequently, there is a clear demand for innovative and efficient methods to manage fungal and bacterial contamination.
In response to this need, the team plan for an integrated approach combining UV-C technology with an organic or plant-based antimicrobial spray. They hypothesize that the unique strengths of these two treatments would provide a complementary efficacy for improved control of apple postharvest pathogens. This strategy not only aims to reduce product loss and enhance food safety but also represents a sustainable and scalable option for the apple industry. There are four objectives to this project:
- Define and optimize UV-C treatment to inactivate decay-causing fungi and foodborne pathogens.
- Identify and evaluate plant-based antimicrobials and organic sanitizers to prevent or delay the growth of decay-causing fungi and foodborne pathogens.
- Optimize integrated lab-scale UV-C and antimicrobial treatment to inactivate and delay the growth of decay-causing fungi and foodborne pathogens on the surface of apples while preserving product quality.
- Assess the optimized UV-C and antimicrobial integrated treatment using a pilot-scale system followed by simulated bulk cold storage.
Project Title: Risk Assessment for Loss of Firmness During Storage in Gala
Organization(s): HudsonAlpha Institute of Biotechnology, USDA-ARS Tree Fruit Research Lab, Washington State University
Principal Investigator(s): Harkess, A.; Yocca, A.; Honaas, L.; Ficklin, S.
Total Funding Amount for All Years: $214,797
Length: 2 Years
New and improved risk assessment technologies are a priority for the apple industry, and a
deeper understanding of how pome fruit respond to various postharvest technologies is a research
priority for the USDA Tree Fruit Lab. The primary deliverable of this project will be new, higher accuracy fruit firmness models for ‘Gala.’ Other deliverables include answers to critical open questions regarding the development of risk assessment tools for postharvest apple fruit traits. The proposed experiments aim to test the team’s hypotheses about ways to improve model performance, namely with regard to data amounts and noise reduction techniques. The team will also begin development of Loop-Mediated Isothermal Amplification (LAMP) assays for high-importance genes. This will bring them closer to a commercial risk assessment technology, that, for practical reasons, aims to design around a small number of genes. They envision that initially the technology could render a prediction about the relative risk for loss of firmness in the postharvest period for equivalent lots of fruit, but eventually more absolute predictions are possible. The objectives of this project include:
- Add additional cultivar years of storage trial RNA-Seq data to improve upon existing firmness
models. - Establish a multi-cultivar genetic framework to study apple fruit quality changes (loss of
firmness) during storage. - Begin development of LAMP assays for a short list of firmness model genes.
Contact
Paige Beuhler (Administrative Officer), 509 665 8271 ext. 2
Ines Hanrahan (Executive Director), 509 669 0267
