A university-industry partnership begun several years ago is bearing fruit – in the form of new technologies that could significantly enhance the sustainability of California’s food processing industry.

Among several projects aimed at improving efficient use of natural resources is a plan to reduce water use and discharge at Wawona Frozen Foods, a multifaceted fruit processing company based in Clovis.

Leading the work for California State University, Fresno is professor Gour Choudhury of the Department of Food Science and Nutrition. Choudhury, who also directs the university’s Center for Food Science and Nutrition Research, is a specialist in food processing systems engineering and development and has obtained several U.S. patents. Directing the work at Wawona is Bill Smittcamp, company president and also a member of the center’s advisory board.

Wawona has been involved with Fresno State in various research and development projects for many years, but the partnership to improve water use efficiency began shortly after Choudhury joined the Fresno State faculty in 2004. He and Smittcamp began discussing sustainability in food processing.

One of their shared concerns was water use.

“Water is the most important and essential input to fruit and vegetable processing plants,” Choudhury said. “Companies use large volumes of water and also generate large amounts of wastewater, and disposal issues are becoming a major impediment to growth and expansion of the food processing industry in the Central Valley, particularly in Fresno County.”

A specific problem in the Fresno area is disposal and treatment of wastewater. The combination of 500,000 residential water users and a few fruit processing plants has brought Fresno’s municipal treatment facility to near capacity. An expansion is planned, but in the meantime, the city may have to reduce inputs.

Smittcamp says the city tends to aim first at industry when it comes to water discharge restrictions, and Wawona is seeking to be preemptive in reducing the company’s water use, as well as wastewater discharge, before increased regulations are enacted.

“The water use issue in anything we do is huge,” Smittcamp said. “Sometimes it just takes another set of eyes to look at our situation and ask questions on how we could do things differently.”

That happened through the new partnership.

Choudhury began exploring ideas for reducing water use and discharge during fruit peeling and in other areas. One idea was to employ a fluid mixture of liquid and gas to take the skin off the peach. A specially-designed process was developed and tested in a laboratory setting at Fresno State; it was successful, with a “very significant” 80 percent reduction in water use, Choudhury said.

Choudhury then designed a commercial prototype unit and contracted with a local manufacturing company for fabrication. Wawona engineers helped to oversee installation and operation in the Clovis plant last summer.

Choudhury has labeled the new process an “eco-friendly lye-peeling system,” because it uses significantly less water than a conventional system and generates less wastewater.

“It peels very well,” Choudhury said. “Now the hard numbers on its water use have to come in.”

That will have to wait till next season. Since the prototype unit was installed late in the processing season last fall, engineers had just enough time to focus on operation and fine-tuning. During the winter months some adjustments will be made, and next summer, analysis of real water use and discharge will be conducted.

If the system proves viable, the processing industry will have an opportunity to increase sustainability statewide.

“Successful implementation of this project will result in the development of a technology that will comply with state and federal pollution control regulations and decrease the discharge from fruit processing plants, thereby reducing the disposal cost,” Choudhury said. “Such a system will reduce water intake and improve the profitability and the overall economic viability of the food processing industry in California.”

Smittcamp noted that cost of conversion to new systems can be high for the processor and will likely take years to accomplish, assuming the technology proves durable. Choudhury said once the process is patented and licensed, it could be manufactured locally and processors would have to purchase the equipment and install it.

Not surprisingly, the intent to reduce water use in processing has spawned other ideas that also are being explored, Choudhury reported. In fact, he is testing a second concept that would reduce water use in another phase of peach processing at Wawona. He also is exploring a third idea for reusing processing by-products as an organic substrate for producing specialty crops such as mushroom.

Research work at the Wawona plant will likely continue for several years as new processing systems are evaluated and improved. Choudhury hopes the efforts will expand industrywide.

Results will be reported, as work continues, through various Fresno State outlets, including through the California State University Agricultural Research Initiative program, which provided funding jointly with Wawona for this work.

For additional project information, contact Choudhury via e-mail at gchoudhury@csufresno.edu.