Dry Bulk Handling of Food Grade Material

November 18th, 2022

Dry food ingredients run the gamut from flour, grains, dry milk products, and sugar to seasonings, conditioners, preservatives, and a whole lot more. These powdered and granular dry ingredients are major components of today's packaged foods. This makes the handling of dry bulk food-grade material an integral part of food processing. 

Food-grade equipment helps to ensure the safety of these dry food ingredients and the products they make. The equipment should not only be clean and efficient, but it should also be durable and dependable.

Read on to find out about the different types of food-grade material and the factors affecting your choice of bulk handling equipment for dry ingredients. Discover how Erie Technical Systems' solutions work with a variety of dry bulk food processing machinery.

What is food-grade material?

The term "food grade" gets used quite often but few of us stop to think of exactly what food grade means. The fact is, it may actually be used in two ways.

One, it might be used to describe the ingredients, components, or materials that make up food and are safe for human consumption. Alternatively, it may be used to describe material that's considered safe to come into direct contact with food products.

Therefore we can speak of food-grade ingredients, food-grade packaging, and even food-grade conveyor belt material. 

Types of food-grade materials

A wide variety of dry food ingredients gets used in industrial-scale food processing. These come in many different forms that must be taken into consideration when selecting dry bulk handling equipment.

Two main forms of dry food-grade material are granules and powders. Powders consist of very fine particles, with common examples being:

  • Cocoa powder
  • Coffee powder
  • Powdered sugar
  • Spice powders
  • Gelatin powder
  • Milk powder
  • Egg powder
  • Powdered food fillers
  • Ascorbic acid
  • Baking agents
  • Potato starch
  • Cornstarch
  • Emulsifiers
  • Flour

Granular dry ingredients are typically grains. The term is sometimes applied to flakes, pellets, and extruded pieces of food material, too. Common examples of granular ingredients include:

  • Salt
  • Cacao beans
  • Coffee beans
  • Cracked wheat
  • Granular spices
  • Raw sugar 
  • Nuts
  • Corn pellets
  • Rolled oats
  • Shredded cheese
  • Shredded coconut
  • Chocolate flakes
  • Potato flakes
  • Rice flakes
  • Wheat flakes
  • Pasta

Bulk handling of dry ingredients

Safe and efficient processing of dry bulk food is achieved by taking the characteristics of the equipment and the ingredients into consideration. Here's a heads-up on four of these.

Mechanical vs. pneumatic food-grade conveyors

Mechanical conveying and pneumatic conveying are both used with food processing machinery, taking food through the different stages of processing. For either type of food conveyor, its mechanisms (controls, valves, belts, etc.) should all meet sanitary food-grade standards.

A mechanical food-grade conveyor is a good choice for heavier, larger food pieces and for mixtures with various particle sizes. It also works with ingredients that are moist and doughy. A mechanical conveyor has the advantage of being better able to keep blends together because it conveys ingredients with a gentler motion than a pneumatic food conveyor does.

Mechanical conveyors may have a lot of exposed moving parts, raising concerns about contamination if these come into contact with food. This can be addressed by the use of food-grade material when constructing conveyors for use in food processing.

A pneumatic conveyor works well with powdered food ingredients that easily fluidize in the system's stream of air. Both the vacuum and pressure models of the pneumatic food conveyor are low maintenance with the added benefits of greater cleanliness and efficiency.

A point that's often overlooked with pneumatic food-grade conveyors, however, is that the quality of the compressed air used in some of these systems might affect food safety and should always be taken into account.

Food safety considerations

A large number of ingredients gets used in food processing. This increases the challenge of safely handling and conveying those ingredients from one piece of food processing machinery to the next.

Each step of the process should be efficient and seamlessly flow to the next step. This way the chances of contamination when handling dry bulk food-grade material will be greatly reduced.

Partial or full automation of batching, loading, and unloading of the material helps, too. It increases efficiency and reduces the chances of cross-contamination that might result from human error.

Automated batching systems, for example, improve food safety with increased traceability. It also allows for lot tracking of the material used in the final product.

Plus, bulk material handling equipment made for use in food processing plants routinely has components made of FDA-approved polymers, corrosion-resistant materials, and stainless steel.

Cleaning of equipment is another food safety concern. It can be addressed either by clean-in-place (CIP) or clean-out-of-place (COP) systems.

Flow considerations

Caking, dust creation, and unwanted separation of ingredients are just a few of the issues often encountered as dry bulk ingredients are moved along during processing. Some of these issues also arise when the material is stored between stages of processing.

Solids flow and settle differently than liquids do and so the equipment used to handle them must be designed with this in mind. Chutes, hoppers, and surge bins that form a part of food processing machinery can be designed to compensate for flow issues such as ratholing, bridging, and flooding.

For example, when the sides of a hopper are smoother and steeper, the materials encounter less friction and gravity is better able to facilitate discharge. A larger outlet and vibration can also ease flowability concerns.

Weighing, blending, and batching

Automation leads to greater accuracy when weighing and blending dry ingredients for packaged foods. Incorrect weights and improper blending can affect the quality of the final product and lead to inconsistent product quality.

Blending poses a particular challenge when it comes to friable ingredients, that is, ingredients that tend to break into smaller pieces easily. Gentle movement and blending of these ingredients is required to prevent this. 

Blending may also affect temperature-sensitive dry food ingredients, as these may cake together instead of remaining free-flowing. Adding an anti-caking agent or adjusting the blend time and speed could address this issue.

Batch processing has the advantage of utilizing more sanitary production techniques than the continuous processing method. It also leads to better quality control over the finished product. Batching, however, can slow production but this downside can be mitigated by directly integrating bulk bag filling and bulk bag unloading equipment into ingredient batching systems.

Food grade bulk material handling from ETS

Erie Technical Systems' bulk handling solutions will leave a good taste in your mouth! Contact us to find out about our vibratory conveyors, feeders, and spiral elevators for use with food-grade material. Be sure to ask about our bulk filling and unloading selections, too, fully automated complete bulk filling production lines. They are scalable to your needs with options to make each component suitable for your application.


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