New protein ingredients present loads of opportunities, but many of them have different properties that impact dough consistency and final product quality.

“Any ingredient like pea or whey protein is going to absorb moisture differently in a dough,” said Nico Roesler, North American snack equipment sales manager, Reading Bakery Systems (RBS). “Depending on particle size, these ingredients can create a gritty mouthfeel in the final product that isn’t appealing.”

To extrude these protein-packed doughs, he added, the doughs need to remain homogenous in the shaping process.

“If the ingredients absorb too much of the water in the dough, the pieces might not extrude properly and can break easily after baking,” Roesler pointed out. “If it’s a gluten-free dough, certain technologies can help with the extrusion process. RBS offers prefeed rollers that grab these more delicate doughs and force them into the extrusion cavity. This eliminates bridging, or air gaps, in the extrusion process, and helps ensure a more even piece weight.”

For any extruded product, food manufacturers must strike a balance between desired ingredients and functionality to create the optimal texture, mouthfeel and taste, noted Rafael Alvarenga, area sales manager, Wenger Manufacturing.

“Without knowing how to make proper equipment adjustments, adding higher protein levels can lead to a harder, denser bite and less puffing when compared to a corn-only extruded snack,” he said.

Mike Shaw, sales manager, snacks and cereals, North America, Bühler, mentioned that protein tends to come in very fine particle sizes that could float when handling or conveying them into an extruder.

He added using a single- or double-screw preconditioner can continuously pre-hydrate and start the thermal cooking process prior to entering the extruders and assist with handling the raw materials.

Protein materials also come in the form of long fibers that are difficult to handle, said Matteo Pasquali, applications manager, soft dough and cookies, GEA Bakery. Others may be large chunks or high-quality inclusions such as legumes or seeds.

“The co-extrusion process could be one answer to combine two different streams of dough or dough plus filling simultaneously to produce filled cookies or bars. Moreover, ingredients such as nuts, fruits or spices can be added to the filling to enhance flavor and texture,” he said. “By optimizing extrusion parameters, pre-processing techniques and incorporating functional ingredients, manufacturers can create innovative, nutritious and appealing protein-based products.”

Andres Lopez, business development director, Handtmann Inc., indicated extrusion may limit waste and eliminate the need to recycle scrap dough that may occur in other processes.

“Protein-based snacks often contain very expensive ingredients,” he said. “Because all those new ingredients are not cheap, it’s really important that you don’t have waste.”

John Barber, regional sales manager, Clextral USA, noted that a large swath of BFY ingredients pose formulation or even end-product development challenges for extruded snacks. They include high-protein, fiber and fat-rich formulations to low-carbohydrate, upcycled ingredients and heat-sensitive probiotics, vitamins and dairy products.

To overcome these issues, he recommended snack producers explore changes to different machine capabilities, such as an extruder’s length-to-diameter configuration, screw profile flexibility, machine controls and various die designs.

This article is an excerpt from the March 2025 issue of Baking & Snack. To read the entire feature on Extrusion, click here.