(Photo courtesy of Caitlyn La Rue)
At first glance, breakfast cereal, breadcrumbs, and candy may not appear to have a lot in common. But all are created via extrusion, a widely used food processing technology and the subject of a recent workshop offered by Washington State University’s School of Food Science.
“Many products are made by extrusion, but not everyone in the food processing industry is familiar with the technology,” said Girish Ganjyal, professor and Extension specialist in WSU’s School of Food Science. “It’s a complex system that’s hard to grasp just by reading a book. This type of intensive workshop helps attendees from around the world gain practical experience and learn the tricks of the trade.”
Around 30 people gathered on the WSU Pullman campus for this year’s three-day course. Using a lab-scale extrusion machine, Ganjyal, his students, and several industry professionals gave lectures and demonstrations.
The workshop centered on direct expanded starch products and plant-based protein products, with topics including extrusion processing ingredients, post-extrusion dehydration processes, and shelf stability of extruded products. The event culminated in a group dinner at the Palouse Ridge Golf Club.
“This outreach is another way to advance the food industry profession and train industry professionals,” said Nancy Deringer, WSU interim associate dean for student success and academic programs and a dinner attendee. “Participants learned new skills, developed new food product ideas, and connected with other food industry professionals. When I visited with the attendees, all were thrilled with the content they were learning.”
Deriving from the principle of Archimedes’ screw, the concept of extrusion has existed for millennia. Modern extrusion machines use heat and mechanical shear to cook raw ingredients, which are funneled into one side of the apparatus, pass through an internal twin screw system, and exit the machine through a die that cuts the now-cooked product — chewing gum, snacks, etc., — into various sizes and shapes.
Extrusion is less costly than many other food industry processes, with the capacity to produce up to 6,000 pounds of product per hour.
“Efficiency is a big deal,” Ganjyal said. “Extrusion allows for multiple unit operations in one machine at the same time. The process mixes, cooks, and melts the product along with shaping and forming it.”
WSU’s annual extrusion workshops attract a diverse range of employees from the likes of General Mills and Mondelēz as well as mid-sized companies and startups. Many workshop attendees sign up to learn more about the food processing system; some are already using the technology but need help troubleshooting.
“The best part of the workshop is interacting with participants and watching that light bulb go on when we offer them solutions to their problems,” Ganjyal said. “Many keep in touch afterward to let us know they successfully implemented our suggestions.”
Workshops like this illustrate WSU Extension’s commitment to using science-based knowledge to educate and help individuals, businesses, and communities locally, nationally, and even globally.
“It is important for Extension to understand the industry’s educational needs and conduct research and develop training that helps them utilize the best technologies and operate efficiently,” said Vicki McCracken, associate dean and director of WSU Extension. “The extrusion workshop included instructors who are current industry members. This kind of partnership in developing programs helps ensure that those programs meet industry needs while bringing in the expertise of university scientists and Extension specialists.”
Another benefit is the increased exposure to WSU’s wide breadth of research. While many workshop attendees initially come to WSU to learn about a specific topic, visiting the campus can also help them learn more about the entire university and the important work being done there.
“Through the extrusion workshop, WSU Extension is making an impact not just in Washington, but across the country,” Ganjyal said. “The event brings people to WSU and shows them what we’re about. While they’re here, we always make sure to give them Cougar Gold cheese so they will keep coming back!”