Breakfast cereal is a type of processed food made from grain and intended to be eaten as a main course. In most cases, it’s served with milk, but it’s not uncommon for people to eat it with yogurt or plant-based milk. Even though the majority of today’s breakfast cereals are served cold, there are some that require cooking. However, these hot cereals are less popular and in lower demand than their cold, ready-to-eat counterparts.
Numerous forms of cereal recipes have been created around the world since as early as the discovery of agriculture, cooking them in water to form various forms of gruels and porridge, similar to today’s hot cereals. Most people in the Ancient Roman Empire ate cereal grains with all meals, including porridge. Cold cereals only appeared during the second half of the 19th century. In large part, we have to thank Dr. James Caleb Jackson, Dr. John Harvey Kellogg, and Charles William Post for this staple American breakfast. Some companies also use cereal, such as granola cereals to make cereal bars.
Over the following decades, this once-healthy, whole-grain breakfast food started to be more processed and filled with sugar. Due to their successful marketing campaigns, the image also changed to a quick, convenient, and tasty food. Another factor to their success was the invention of corn flakes, which were more popular than wheat flakes. Today, 9 out of 10 Americans consume ready-to-eat breakfast cereals on a regular basis.
Raw Materials Used in Breakfast Cereal Production Lines
Unsurprisingly, the most common raw material used in traditional cereal is grain. The usual grains used are corn, barley, wheat, oats, and rice. Hot cereals like oatmeal, as well as some cold cereals like shredded wheat, have no additional ingredients. However, most breakfast cereals use a multitude of other ingredients, such as salt, sweeteners, yeast, coloring and flavoring agents, added vitamins, minerals, and preservatives.
White and brown sugar, corn syrup, malt obtained from barely, and even concentrated fruit juice are being used as sweeteners in the industry. As far as flavors are concerned, the usual include chocolate, cinnamon, fruit, and other spices. Nuts, dried fruit, and marshmallows are also used for added flavoring. In many cases, vitamins and minerals are also added as a means of making up for the nutrients lost during the cooking process. Roughly 90% of vitamin B1 is destroyed by heat. Preservatives and antioxidants such as BHT and BHA are usually added to breakfast cereals to prevent them from going stale or rancid.
Technologies and Equipment in Cereal Processing and Production
To better understand the food processing technology and equipment that the cereal manufacture industry uses, we need to look at the manufacturing process for each type of cereal. The first step of the production process, regardless of the type of cream, is grain preparation. Grain, be it in the form of corn, wheat, oats, barley, etc., is brought to the cereal facility, inspected, and cleaned. Depending on the breakfast cereal, it may be used in the form of whole grains or may require some additional processing. In the majority of cases, the whole grain is crushed between metal rollers to remove the outer layer of bran. Sometimes, this grain is ground into flour.
- Grains – If whole or partial grains are used, these are mixed with flavoring agents, sweeteners, salt, vitamins, minerals, and water in a rotating pressure cooker. All variations, including time, temperature, and rotation speed depend on the type of grain being used. Once cooked, the grain is moved over a conveying system through a drying oven. It’s important that enough moisture remains in the cooked grain so it will be a soft, solid mass that can be shaped as required.
- Flour – If ground flour is used instead of whole or partial grain, a twin-screw cooker extruder is used, as opposed to a rotating pressure cooker. These twin-screw extruders mix the flour with all the other ingredients, such as salt, water, sweeteners, vitamins, food coloring, etc., mixing and cooking the composition as it travels along. At the other end of the extruder, the cooked dough emerges as an elongated ribbon, which is then cut by a rotating knife. The resulting pellets are then processed in a similar manner to cooked grains.
- Flaked Cereals
The most widely-consumed breakfast cereals are also the most straightforward to produce. Corn flakes are the most common, but flaked cereals can also be made out of wheat, barley, oats, and rice. In any case, once the grains have been cooked, they are allowed to cool for several hours so that the moisture content within each grain has a chance to stabilize. This is what’s known in the industry as tempering.
Once this process is complete, the grains are flattened between two large metal rollers under high pressure. The resulting flakes are then conveyed to an oven. Inside the oven, they are exposed to a blast of hot air that removes any remaining moisture and toasts the flakes until the desired color and flavor is achieved. It’s important to mention that flaked cereals can also be used to make extruded pellets by using a similar method.
● Puffed Cereals
Puffed cereals are also highly desirable among consumers. Typically, these types of cereal are made out of rice but can also be made out of wheat. The ovens used to puff the grains are known as guns. Unlike wheat, puffed rice is easier to produce as it requires no pretreatment. Once the rice is cooked, it is cooled and dried. Next, it’s rolled between metal rollers, similar to flaked cereals, but it’s only partially flattened through a process known as bumping. The bumped rice is then dried once again and placed in a very hot oven where it expands.
Puffed wheat cereal, on the other hand, needs an additional level of treatment to remove the outer layer of bran. This is typically done using grindstones in a process known as pearling. A different process is to soak the wheat grains in saltwater. This brine-like solution hardens the bran, which causes it to break off during the puffing process. The grain is then placed in the gun, which is a relatively small vessel that holds hot steam at high pressures. The gun is then opened suddenly to release the pressure and puff the grain. The same process is applied to extruded pellets.
● Shredded Cereals
Shredded cereal is most commonly made out of wheat. Unlike the other processes above, shredded cereal is made by cooking and boiling the wheat in water so the moisture can fully penetrate the grain. The grain or extruded pellets are then tempered and rolled between two metal rollers. While one of the rollers is flat, the other one is grooved. A metal comb is set against the grooved roll, and a tooth is placed inside each groove. Due to its high moisture content, the grain is completely shredded by these teeth, dropping off the rollers as a continuous ribbon. This ribbon is then cut to the appropriate size and baked until the desired color and dryness is achieved.
Granola and other similar products are typically made of oats and use a mixture of nuts, seeds, fruits, flavors, etc. These are cooked as a mixture alongside sweetener and oil to bind all the ingredients together. Once finished, these are crumbled to the desired size.
● Hot Cereals
Hot cereals are made by processing the grain, depending on what type it is. Oats are typically rolled or cut, wheat is cracked, while corn is milled into grits. These are then partially cooked, so as to shorten the time it takes the consumer to cook them in hot water or milk. Other ingredients, such as salt or sweeteners, may or may not be added, depending on the recipe.
● Shaping and Coating System
As most of us know, breakfast cereals come in a wide variety of shapes and sizes. These can be loops, letters of the alphabet, animal-shaped – you name it. To achieve these shapes, a die is fitted at the end of the extruder, allowing the ribbon of cooked dough to take the desired cross-section shape, which is then cut by the rotating knife at the desired size. These pieces are then processed in a similar way to puffing, but they only partially expand to maintain their special shape.
After shaping, some cereals may be coated with sweeteners, vitamins, minerals, different flavors, preservatives, and food coloring. Frosting is applied in a rotating drum by spraying the cereal with a thick layer of sugar syrup. As the syrup dries, it turns into a white layer of frosting.
● Conveying and Packaging
While some types of cereal, such as shredded wheat and hot cereals, are fairly resistant to moisture damage and can be placed directly in cardboard boxes, most others need to be packed in waterproof and airtight plastic bags.
Some typical film materials used in breakfast cereal packaging include:
- Biaxially-oriented polypropylene (BOPP)
- Low-density polyethylene (LDPE)
- Polyethylene terephthalate (PET)
- Metallised PET
- Aluminum foil
These materials can be used in different combinations.
As far as conveying goes, the breakfast cereal industry has traditionally used a variety of systems, including flat belts, buckets, and aeromechanical, pneumatic, or auger conveyors. However, these systems have been struggling to keep up with the industry’s demands, particularly in terms of cost-efficiency, integration, automation, and cross-contamination. Tubular drag conveyors, on the other hand, have proven themselves to provide the necessary flexibility and integration capability with all breakfast cereal types and processes. These conveying systems used in the food industry are ideal for moving the breakfast cereal product through the extrusion, forming, tempering, flaking, and toasting processes, then on through the coating and packaging processes.
Cablevey’s Cereal Conveyor Systems can move up to 1,500 cubic feet of product per hour in an enclosed tube without the use of air. It also comes available in a multitude of layouts and eliminates the risk of product separation, degradation, or cross-contamination.