Education Lab

Fresno State prof's idea would conserve ag water

Millions of gallons of water run through fruit processing plants every year, generating high costs and an ocean of waste for companies nationwide.

But all that could change with technology developed by Fresno State professor Gour Choudhury.

Choudhury, a specialist in food processing systems, has devised a system that uses air, rather than water, to blast peels off fruit. The invention could slash the water use by 80%, saving companies each tens of thousands of dollars a month.

The project has been three years in the making and could soon be on the market as an eco-friendly solution for processors of peaches, tomatoes and other soft fruit that needs to be peeled.

For Choudhury, who already has several U.S. patents, sale of the system could be another feather in his academic cap. Fresno State would benefit as well, collecting royalties because Choudhury invented the system as an employee of the university.

Big research schools like the University of California are accustomed to handling patent revenue. But "this is relatively new territory for us," said Joe Bezerra, executive director of the California Agricultural Technology Institute at Fresno State.

Bezerra said Choudhury's project is important because it could save processors money, reduce water consumption and cut the discharge of contaminated waste water.

Industry officials are watching closely.

"There is a lot of interest in this," said Ed Yates, president of the Sacramento-based California League of Food Processors. "Anything that uses less water, energy and chemicals will help keep us compete against the rest of the world."

Traditionally, processing plants slice fruit in half, remove any pits and wash them in a lye solution that loosens the skin. Then a jet of water knocks off the skin as the fruit moves along a conveyor belt.

Choudhury's system substitutes blasts of moisturized air in the final step. Some water is still needed to rinse away the lye, but far less than the half-million gallons a day that traditional systems can require.

The invention began after Choudhury, a former professor at the University of Wisconsin-Stout, arrived in Fresno in 2003. One day he visited Bill Smittcamp's Wawona Frozen Foods plant in Clovis to find out what his biggest challenges were.

The family-run company is a pioneer in the frozen fruit industry, making products for food manufacturers, food service distributors, restaurants, resorts, supermarkets and schools. More than 100 Wawona products are sold and distributed throughout North America.

"I wanted to know what some of the major problems the industry was facing, and Bill told me: 'Water, water, water,' " Choudhury said. Water is expensive to buy, and the lye contamination requires treatment -- also expensive.

After months of research and experimentation, Choudhury and his students designed a prototype that slashed Wawona's water usage per ton of fruit from 240 gallons an hour to 48.

A prototype set up in the Wawona plant has worked well, the company says. Fully implemented, it could save the plant at least $50,000 a month in water and wastewater charges, Choudhury says.

Fresno State submitted a patent application for Choudhury's system last year. Now university officials are working out who will manufacture the equipment, who will sell it and what it will cost.

Choudhury said a Madera company is interested in making and marketing the technology, but nothing has been decided. And the cost of the equipment is estimated at $300,000 to $500,000.

The capital cost is a critical ingredient in the question of how well the invention will fare in the marketplace, said Yates of the food processors league. If the price is too steep, processors -- who can never be sure of crop quality and market conditions from one year to the next -- may be unwilling to invest, he said.

Also still to be resolved is how the revenue from the technology would be shared. Bezerra said a committee made of representatives from the California State University system is working on how to manage marketing licenses and fees. Choudhury and the university also must work out whether he should share in the royalties.

As far as Choudhury is concerned, this is just the beginning of the possibilities for his department.

He is already working with a local tomato processor to test the equipment's effectiveness on peeling tomatoes. And he is working on neutralizing the lye in the peach peels to make it suitable as cattle feed. If he can figure out how to remove the pectin from the peel and sell it as by-product, he will do that too.

"There are many, many possibilities," Choudhury said.

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