Announced on September 25, 2025, the project titled “Producing High-Quality, Shelf-Stable Sweet Cherries using Vacuum Microwave Drying (VMD) Technology” represents a collaborative effort between academia, industry, and government. Led by Dr. Youngsoo Lee, an associate professor in WSU’s School of Food Science with expertise in food engineering, the team includes co-investigators Dr. Kang Huang and Dr. Claire Murphy. Partners include local sweet cherry growers and experts from the U.S. Army Natick Soldier Systems Center (NSSC) in Massachusetts, known for its advancements in military ration technology.
Washington State dominates U.S. sweet cherry production, accounting for over 60% of the nation’s output, with annual harvests often exceeding 200,000 tons. The industry, valued at hundreds of millions of dollars, thrives in the region’s ideal climate of warm days and cool nights, which yields premium fruit prized for its size, sweetness, and deep red hue. However, this abundance comes with challenges. Market saturation, exacerbated by overlapping harvests from competing regions like California and Oregon, has led to plummeting prices in recent years. In 2025, despite excellent fruit quality, growers faced record-low wholesale prices, sometimes as little as $1 per pound, forcing many to leave surplus cherries unpicked or discarded. Natural disasters, including heat waves and early ripening, have compounded these issues, as seen in 2024 when extreme weather caused significant crop losses. Labor shortages, driven by immigration policies and delays in seasonal worker arrivals, further strain operations, with fears of deportation adding to the uncertainty.
“Surplus cherries represent a missed opportunity,” explained Dr. Lee in the project’s announcement. “By converting them into high-value dried products, we can reduce waste and provide growers with economic stability during tough seasons.” Dr. Lee, who holds a bachelor’s degree in food engineering from Yonsei University in South Korea and a Ph.D. in food science from the University of California, Davis, brings extensive experience in food processing and quality preservation to the endeavor. His work at WSU emphasizes innovative technologies to extend shelf life while maintaining nutritional value.
At the heart of the project is VMD, a process that combines microwave energy with a vacuum environment to dry foods rapidly and efficiently. Unlike traditional hot-air drying, which can take hours and degrade color, flavor, and nutrients, VMD operates at lower temperatures, typically below 50°C (122°F), to evaporate moisture quickly while preserving the fruit’s integrity. The vacuum reduces the boiling point of water, allowing drying in minutes rather than days, with energy savings of up to 90% compared to freeze-drying. For cherries, this means retaining antioxidants like anthocyanins, which give the fruit its health benefits and vibrant appearance. Studies on similar fruits, such as tomatoes and berries, have shown VMD reduces processing time by 70-90% while minimizing microbial risks.
Complementing VMD are edible coatings infused with bacteriophages, viruses that target and destroy specific bacteria without harming humans or the environment. These coatings act as a moisture barrier to prevent rehydration and spoilage, while the phages combat pathogens like Salmonella and Listeria, common concerns in fresh produce. Research has demonstrated their effectiveness in extending the shelf life of fruits, vegetables, and meats, with applications in biopolymer films that are safe for consumption. Dr. Huang, an assistant professor in WSU’s Department of Biological Systems Engineering, specializes in food-microbe-material interfaces. With a Ph.D. from Zhejiang University and prior roles at the University of Auckland, his expertise in biomaterials will be crucial for optimizing these coatings.
Food safety is a core focus, with Dr. Murphy leading evaluations of bacterial survival during processing. As WSU’s food safety extension specialist, she holds a Ph.D. in food science and technology from Virginia Tech, along with a master’s in public health, and has dedicated her career to reducing contamination risks in agriculture. “Ensuring the final product meets rigorous safety standards is essential for consumer trust and market acceptance,” she noted in project discussions.
The collaboration with the U.S. Army NSSC adds a layer of practical innovation. Located in Natick, Massachusetts, the center, often called the Natick Lab, develops advanced food technologies for military rations, including vacuum-dried items that must withstand extreme conditions without refrigeration. Their expertise in portable, nutrient-dense foods aligns perfectly with the project’s goal of creating intermediate-moisture cherries, products with water activity low enough to inhibit microbial growth but high enough to remain chewy and flavorful, unlike fully dehydrated snacks.
Over the project’s duration, expected to span several years, the team will conduct lab trials, pilot-scale drying, and sensory evaluations to refine the process. Key metrics include texture retention, nutritional preservation, and phage efficacy against bacteria. Grower input will ensure scalability, with field tests involving surplus fruit from orchards in the Yakima Valley and other key regions.
The implications extend beyond economics. By diverting excess cherries from landfills, the technology promotes sustainability, reducing food waste that contributes to greenhouse gas emissions. For consumers, it means access to year-round, healthy cherry snacks, potentially in forms like infused trail mixes or gourmet confections, that retain the fruit’s natural benefits, including heart-healthy compounds and fiber.
Industry stakeholders are optimistic. “This could open doors to premium export markets and value-added products,” said a representative from the Washington State Tree Fruit Association, echoing sentiments from growers facing ongoing pressures. As global demand for convenient, nutritious foods rises, WSU’s work positions Washington’s cherries as a model for agricultural innovation.
While challenges remain, such as scaling VMD equipment for commercial use and navigating regulatory approvals for phage coatings, the project underscores the power of interdisciplinary research. As Dr. Lee summarized, “We’re not just drying cherries; we’re building a more sustainable future for the industry.” With USDA support, this effort could redefine how surplus crops are handled, benefiting growers, processors, and eaters alike.
