Milling 101: Good Manufacturing Practices

Safety is a core value at Didion and we are committed to producing quality, safe products for our customers. An effective food safety system is a top priority, but how do we create a good basis for it? We do this by having certain rules and expectations in place that employees and visitors must follow whenever they are in our facility. These guidelines are known as Good Manufacturing Practices or GMP’s.

GMP’s are practices defined by the FDA that set guidelines for different manufacturing workplaces. For food manufacturers like Didion, these guidelines provide minimum requirements we must meet to ensure our products are safe and of high quality. These guidelines don’t necessarily tell a company how to manufacture, but rather list factors that need to be monitored during production.

Even though GMP’s are regulated by the FDA, they were established to be flexible so that each manufacturer can decide individually how to implement the best practices for them. This means that Didion can add to the list of already established GMP’s. In fact – the Didion list of GMPs includes 18 guidelines! Many of these rules regard aspects such as: proper attire, hair/facial hair restraint, food/drink consumption, sanitary issues etc.

GMP’s are a very important part of Didion’s safety culture because they are an integral part of a Hazard Analysis and Critical Control Points (HACCP) prerequisite program, which is necessary to build a complete food safety program. Having a good basis by practicing GMP’s allows Didion to become certified to the internationally recognized food safety standard of FSSC 22000, one more step in the food safety management program.

One of the reasons Didion has been able to achieve such high food safety ratings is because we have a knowledgeable food safety leader and team established to help enforce these guidelines. This team is cross-functional and monitors everything from corn procurement to shipping! Along with Didion employees following these guidelines, we also make sure that we check visitors at the mill and have them read and sign off on GMP’s.

Ultimately, it is Didion’s responsibility to practice good food safety so that we produce the safest and highest quality products for our customers. Having effective GMP’s in place helps us accomplish this important task!

By: John Deininger, Quality Assurance Manager at Didion Milling


Corn Milling 101 Part 5: Corn Properties in Baking

Corn flour is an important ingredient in many foods found on the shelves of your local grocery store. Why is it so great?

Three types of corn are commonly used as a bakery ingredient: yellow corn, white corn and alkali-processed corn. We’ll focus on the type that Didion processes – yellow dent corn.CornBreadMuffins_DT

Yellow corn flour’s short-texture proteins give baked goods a crumblier feel than traditional wheat flour. Corn also adds a sweet, nutty flavor to recipes – perfect for breads, muffins or adding in to other recipes.

In addition to taste and texture properties, yellow corn flour has a number of health benefits for those who require a gluten-free diet. Corn is naturally gluten-free – because it does not contain gliaden or glutenin, the two specific wheat proteins that have been shown to cause sensitivity to gluten. Yellow corn flour brings protein and starch to recipes without causing sensitivity, making them perfect for gluten-free baking.

It has great taste, texture and nutritional benefits. It is a simple, recognizable ingredient on nutrition labels. No wonder yellow corn flour is found in many products on your grocery store shelves. It’s naturally good, made great!

By: Todd Giesfeldt, Mill R&D Senior Manager

Corn Milling 101 Part 4: Product Quality Tests

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The quality of our corn products is very important to us. That’s why we perform extensive quality assurance, laboratory and gluten-free compliance testing during numerous stages of our corn processing.

For Quality Assurance (QA) testing, samples are first taken from the mill and tested every two hours to control output from the mill. Next, line samples are taken to check attributes as the final “package” is being filled – they can be bags, tote sacks, tank trucks or bulk rail cars. Finally, a composite sample of the finished lot is taken.

The QA testing program encompasses a variety of product attributes depending upon the application of the item. These laboratory tests include:

  • Granulation
  • Protein & fat
  • Crude fiber
  • Total dietary fiber
  • Ash
  • Titration for calcium
  • Moisture
  • Color – B value (yellow) & L value (brightness)
  • Viscosity
  • Microbiological testing
  • Mycotoxins

In addition to quality assurance and laboratory testing, gluten-free compliance testing is done on a regular basis. Although corn is naturally gluten-free, weekly tests are performed on Didion products to confirm that wheat is not present in whole corn from the harvest/storage/transport chain. This testing protocol confirms our gluten-free status and certification by the Gluten-Free Certification Organization (GFCO).

By: John Deininger, Quality Assurance Manager at Didion Milling

Corn Milling 101 Part 3: Cleaning, Cracking & Sifting

The first step in corn processing is cleaning. We remove any cobs or stalks and sort out broken kernels using a screener and separator. Then the corn goes through a magnet to pull out any remaining foreign material. When the cleaning process is finished, the whole corn kernels should be all that’s left.

The clean, whole kernel corn is then sent to the tempering system to loosen the skin, otherwise known as bran or pericarp. A small amount of water is added to the corn and then it sits in a holding tank for a period of time.

After the skin has been loosened, the corn goes to Didion’s degermination system. The corn is cracked into large pieces. During this process, the loose skin comes off the kernel and the germ pops out. For more information on the parts of the corn kernel, check out Milling 101 Part 2: Where Our Food and Fuel Products Come From.

The fractionated pieces are sifted to sort out any fine, floury materials. These soft, starchy pieces are sent to our ethanol plant because they are optimal for fermentation. For more information on how we maximize every kernel of corn through the partnership between our dry corn mill and ethanol plant, check out Milling 101 Part 1: A Fresh Look at Corn Milling.

Next, the bran is removed using an aspiration system. Then it is transferred to its own system within the mill. The remaining starch goes through a series of grinding and sifting. Pieces are sorted using wire screens of various sizes to separate “unders” or “fines” from the “overs” and “select” pieces. These terms refer to where the pieces sit on the wire screens during sifting.

The fines go to the ethanol plant for fermentation while the overs and select pieces are used to make food products in the dry corn mill. Our millers prefer the select size pieces, which is a nice center cut of the kernel. These “center cut” pieces are made from the hard starch. This enables our millers to make a very consistent finished product for customers and product consumers. This is part of the Didion Difference.

By: Curt Miller, Corn Milling Operations Manager at Didion Milling

Corn Milling 101 Part 2: Where Our Food & Fuel Products Come From

Food and fuel start with the corn kernel and its four unique parts: the endosperm, pericarp, germ and tip cap. We use those four parts of the corn kernel to make grits, meals, flours, brans, pregelatinized flours and whole grain corn flours; as well as ethanol.

Parts of the kernel

Endosperm – The endosperm carries most of the dry weight of the kernel. This part of the kernel contains starch, which is commonly used in food. The endosperm provides the starch necessary to produce sugar molecules for ethanol production. Products that come from this part are grits, meals and flours. Flour is the finest out of all three products made from the endosperm and grits are coarsest.

Pericarp – This part is the outer covering of the kernel that shields it from bugs. It also preserves the nutrient value of the inside. The pericarp is used for corn bran found in everyday foods.

Germ – The germ is the only living part of the kernel and is the centermost piece. This part stores genetic information, enzymes, vitamins and minerals for the kernel so it can grow when it is on the ear. Twenty-five percent of the germ is oil, making it one of the most valuable parts of the kernel.

Tip cap – This part attaches the kernel to the cob. Water and nutrients flow through here to help the kernel alive.

Whole kernel – We grind the whole corn kernel down to a specific granulation to make our whole grain corn flour.

By: Dow Didion, President of Didion Milling

Corn Milling 101 Part 1: A Fresh Look at Corn Milling

Didion-DifferenceOur passion is to provide the highest quality corn products for our customers. The corn we process goes into the products our families eat every day. That’s something we’re very proud of. That passion has carried us through 40 years in business and will continue to drive us for years to come. By hiring great people, innovating to produce excellent products and continuing to focus on exceptional service, we keep looking for ways to reinvent the way we do business. That’s the Didion Difference!

Overall, the U.S. dry corn milling business grows one percent to two percent per year, so our unique approach to corn milling is our key to being competitive in the domestic market. We’ve grown because of our sustainable business model – built on the synergy between our facilities. The dry corn mill and ethanol plant need complementary inputs, enabling us to glean the greatest value from every piece of every corn kernel that passes through our facilities. We carefully select the best parts of the kernel for food production and use the rest to make homegrown biofuels. The consistent input and constant innovation drive efficiency and sustainability in both facilities. This results in high-quality finished products for our customers.

Our small size and family-owned mentality have given us an edge because we can respond quickly to market demands and customize products to customer needs. It all comes back to our passion for maximizing every kernel of corn that passes through our facilities. That passion inspires us to take a fresh look at corn milling every day. At Didion, innovation is a way of life. And we’ll never be done improving.

Milling 101 is a six part series about Didion’s unique approach to corn milling, our products and quality standards. 

By: John Didion, CEO of Didion Milling