Oat milk and other beverages featuring oats are beginning to appear more and more on supermarket shelves. These oat-based drinks are made with various types of oat flour, each differing slightly in flavor, texture, and nutritional elements. These flours are characteristic in how they thicken, gel, stabilize, and disperse within liquid products and how they feel within a person’s mouth. In order to produce these unique oat flours, new milling techniques are being developed. One of these was the air knife, developed for one of Prater Industry’s clients. 

Air Knife Origin Story

The development of this innovative manufacturing implement began when a client wanted to test one of Prater’s Fine Grinder Mills on a specific oat-based product. The mill was configured to mill the oats to a very fine particle size. After only a short test run, build-up in the mill occurred. 

When this happens, the line needs to be shut down, as buildup can damage the mill and rotor, along with blinding the screens so flour cannot get to the conveyor. Had Prater’s team continued with the test, it could have potentially caused the whole system to shut down, an event sometimes referred to as “choking the mill.”

Something needed to be done to keep the product moving and suspended. The team discussed the problem and how to solve it. 

Then one team member said, "Let's try some air." 

So, Prater’s lab technicians added more airflow to keep the product suspended and moving. The experimentation to resolve this issue resulted in the air knife, an accessory that can be added to a fine grinder to mill oats more efficiently. Yet, the solution did not end there, as the Prater team decided to couple the air knife’s capabilities by applying a special coating to keep oat flour from sticking to protect the milling machine further. 

Solving Problems in Oat Processing

Milling oats into a fine powder is extremely difficult. High moisture and oil content can cause multiple issues during short production runs or test runs. Due to this, oats were generally not used for flour until recent years. A 2011 study comparing lipids and fatty acids between oats, barley, sorghum, rice, and wheat found that oats contained more oils than the other grains. In fact, the oil content in both whole and dehulled grains oats was nearly triple that of wheat. 

Problems inherent in the fine milling of oats include: 

  • Can damage rotors should the machine crash. 
  • Causes more buildup, which requires more stopping and starting of the production line to keep machinery clean and limit the time that the mill can run continuously.
  • Fine powders can fill the holes in screens, preventing products from moving out of the mill, commonly called “blinding of the screens”.
  • Oat flour requires very fine grinding, with an average particle size below 75 microns (about 200 mesh). 
  • Puts more wear and tear on the mill, lessening its lifecycle. 
  • Sticky product clings to interior machine surfaces, building up to a point where it can clog and even ruin equipment. 

The air knife helps resolve these problems. 

How the Air Knife Works

In simple terms, the air knife creates sufficient airflow to keep the milled material suspended in the milling chamber longer thereby keeping the internals of the mill clean. An air knife is not a standalone piece of equipment, it is an accessory that can be added to new or existing mills. To operate, an air knife uses a pressure blower to pump air through a small slit in order to create sufficient air velocity to keep fine powders from settling within the mill. This airstream helps fine grinding mills to efficiently mill products with high moisture and oil content. 

While the Prater team incorporated the air knife to solve a problem with milling oats, this new implementation will probably prove useful for other tasks. Its applications will likely include any powdery product that contains high amounts of oil and moisture. And, although it solves this problem for which it was developed well, Prater’s technicians will continue to experiment, improving upon the air knife’s design to make it work even better.  

Products Made from Oats

As a food product, oats provide an excellent source of dietary fiber. Oat flour can be used in a wide variety of products. Its use in drinks like oat milk helps make products less grainy and greatly lessens their bitterness. Oats are also used in a number of products that treat skin conditions and as an ingredient in beauty products, including shampoos and moisturizers. During production, it is finely ground to help achieve better absorption into the body, either through ingestion or application to skin and hair. 

Oat can be made into the following food products:

  • Baby food made out of whole oats.     
  • Beverages from liquified whole oats, such as probiotic drinks.     
  • Biscuits and cookies made from oat flour.   
  • Bread using flour, starch, and lecithin from oats. 
  • Breakfast cereal made from whole oats.    
  • Dry mix beverage products from whole oats. 
  • Fat substitute made with soluble beta-glucans and oat dextrin
  • Granola bars and cereals made with whole oats and resistant starch fractions
  • Non-dairy fermented yogurt made with whole oats. 
  • Oat milk made from the extract of whole oats.
  • Pasta made out of oat starch. 
  • Stabilizer for ice creams made from the oat’s beta-glucans.
  • Substitute for fat made from oat bran and used in a variety of dairy and bakery products, along with meatballs.     

Oats also show promise for various health conditions beyond skincare, for which a substance called beta-glucans plays a prominent role. Beta-glucan molecules are found primarily in the oat kernel’s endosperm, especially in its outer layers. Oats contain about 3-6 percent of these beta-glucans by weight.  

Its clinical uses include:

  • Anti-cancer effects due to beta-glucans and short-chain fatty acids.    
  • Helps maintain gluten-free diets through use of any part of the oat.     
  • Lowers cholesterol due to beta-glucans.

Oats also have industrial uses, with their husks being used to make methane for biofuels. 

Prater as Problem Solvers  

The incorporation of the air knife is just one way in which Prater works with its clients to solve problems. While it serendipitously allows Prater to enter new markets, this was not the original purpose for its development. The air knife, quite simply, was developed to solve one client’s particular problem. But their commitment to resolving it did not end with the air knife. Prater also worked with a third party to develop a special coating for grinding mills that helps prevent buildup. 

Many food manufacturers tend to avoid products that include oats or other high oil and moisture ingredients, because of the hassle in processing them. Prater’s new application of an air knife helps make oat processing easier. The company has high hopes for its air knife, which is likely to soon find other uses. But beyond that, it also shows how Prater and its team of innovators work to achieve the best results for all their clientele, often tailoring its designs to meet clients’ needs. Prater goes above and beyond other milling and other size reduction equipment manufacturers to find solutions to difficult problems.