Extrusion, agglomeration, packaging

Published 5:00 pm Tuesday, April 6, 2010

What is the process to make a puffed cereal?

The process starts upstairs with blending.

The material is dropped into the extruder, mixed with water and made into a dough.

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It then goes through a section with two screws that work the dough.

Pressure pushes the product through a die plate that forms the shape — such as a circle or rice-shape.

 It then reaches atmospheric pressure and expands.

The piece is cut off and sent through a drier where it is cooled to room temperature and packaged into bulk bags or boxes.

Through agglomeration:

Protein concentrates


Protein isolates

Therapeutic fiber beverage mixes

Hydrocolloid gums 

Sports/nutritional beverages mixes

Modified food starches

Soup, sauce, gravy mixes and many more

Through extrusion:

Whey and soy snacks

Puffed snacks and cereals

Soy and whey crispies

Textured soy protein pieces

Multigrain crisps

For crisps, cereals:



 particle size




For powdered drink mixes:



particle size distribution

loose bulk density



—Information from Zumbro River Brand’s Executive Vice President Jim Fischer

Though the economy has been down during the last year, things at Zumbro River Brand in Albert Lea are starting to look up.

Pamela Sander, president of the company, said Zumbro River Brand, in the Northaire Industrial Park, has seen an increase in activity during the last quarter of 2009.

“We’re looking forward to this year being good,” Sander said.

The company, which formed in Owatonna and expanded to Albert Lea in 2006, has three main parts: extrusion, agglomeration and packaging. It is a contract food manufacturer that makes part and complete food products to customer specifications and then packages them.

The most popular products, Sander said, are crisps that can be put into high-protein bars or other bars.

Zumbro River Brand also works with companies supplying diet programs similar to Nutrisystem and can make things like high-fiber beverages or high-protein products for weight loss or body building.

Sander said the company looks to produce products that are unique.

It also conducts clinical studies and can work to develop a new product when asked.

Though she could not name the specific companies the business contracts with, Sander said many of the customers are well-known companies. Some are not known as well, but many are in the nutritional supplement industry.

The customers come mainly from across the United States and Canada, though there have also been some in Europe and Australia, said Sander and Executive Vice President Jim Fischer. The customers ship worldwide.

Fischer said the company is proud to be able to produce innovative, high-quality product.

The following is an explanation of the three areas of work performed at Zumbro River Brand.


Extrusion is the process by which pasta, snacks and cereals — such as Cheerios — as well as the tiny crisps that make up protein and nutrient bars are made.

For the snacks and cereals, the company can make product in the shapes of rings, puff balls, stars, ridges or noodles.

They can be made high protein, high fiber, gluten-free or organic, to name a few specialties with ingredients such as soy, whey, rice, corn, oat, tapioca, potato or multigrain.

The crispy pieces can be up to 80 percent protein from whey or soy or combinations of the two, and can be any of the same specialties as with the snacks and cereals.

Through the extrusion process, the company can also make texturized vegetable protein and pasta.


Batch agglomeration makes powders that stir into liquid without clumping, such as instant hot chocolate or tea.

The process takes a fine powder and agglomerates it into larger particles. Sander said the company can take a lot of things and stick them together, such as proteins, flavors and vitamins.


Lastly, Zumbro River Brand packages the products it makes.

It does different types of packaging at each the Owatonna and Albert Lea locations.

In Owatonna, there is more packaging of pieces, such as the cereals, in bags from as small as an individual-size potato chip bag to as large as a cereal box-size bag, Sander said.

In Albert Lea, there is more packaging of the powdered mixes and also stand up zippered bags for packaging, she said.

Zumbro River Brand in Albert Lea can be found at 1215 Hershey St.

There are currently 55 employees at Zumbro River Brand between the Owatonna and Albert Lea locations.