Spray Drying Specialty Ingredients

As the health food and dietary supplement industry continues to grow, companies are looking for a way to keep up with demand. In many cases, this means working with contract manufacturers to find new ways to incorporate specialty ingredients into products. American Custom Drying (ACD) is a contract manufacturer that has over 60 years of experience working with specialty ingredients. ACD uses their Specialty Ingredients Dryer to help their clients take specialty ingredients and transform them into dry powders that are shelf stable. This gives food and supplement brands the ability to incorporate high quality ingredients into their products, without having to worry about expensive or impractical preservation methods.


What defines a specialty ingredient?

As this demand for specialty ingredients increases, it begs the question: what exactly is a specialty ingredient, and how does it differ from other ingredients that food manufacturers use? There are two defining qualities of specialty ingredients. The first is that they are financially valuable and typically have a high dollar value. The second is that they are unique in some way. The range of items that can be considered specialty ingredients are very broad, which requires contractors to be creative in their preservation solutions.


Some examples of specialty ingredients include sought-after vitamins and minerals, pre and probiotics, enzymes, nutraceuticals, and phytonutrients. These ingredients are typically made in very small batches and require highly controlled environments. They often add nutritional value to foods, and in some cases can affect the way the body processes the food as well. Adding these ingredients to a food product or supplement can immediately increase its desirability as well as its financial value.


In order to take these specialty ingredients and turn them into shelf-stable powders, contractors require very strict quality control standards. Managing these intense standards requires a specialized team of food scientists and chemical engineers. They must have experience transforming liquids to powders, which is something that happens not only in food processing, but also in developing cosmetics, personal care items, soft chemicals, and artificial flavors.


This team will first need to conduct a detailed review of the liquid ingredient’s physical and chemical limitations. From there, they will need to develop inline manufacturing testing of active components. The final step is to test the finished product in a laboratory setting. This entire process is done with the goal of creating the highest quality possible in the finished product.


Every specialty ingredient has its own unique processing requirements. Some ingredients can only withstand limited exposure to heat, regardless of whether they are in a powder or slurry state. Others have restrictions regarding the particle size or the pH levels that they can accommodate. Still others require the use of flow-aides or pre-filtration. In some of the most extreme cases, specialty lipids, a maltodextrin carrier or gum must encapsulate the particle in order to turn it into a powder that can stay shelf stable.


What is spray drying?

Spray drying is the process of using hot gas or air to evaporate the water in a liquid or slurry, transforming it into a powder. This has become an industry standard in food processing for drying substances with heat sensitivities, and it works well for a wide range of specialty ingredients. Spray drying is very precise, and the process itself can vary depending on the qualities of the substance in question. There are various attributes that must be considered before spray drying can take place. These include:


1-    Rheological properties: Rheology, or the study of the flow of matter, is a crucial point for spray drying. Rheology typically applies to liquids and soft solids, which is the state these specialty ingredients are in before the spray drying process begins. Important rheological properties to assess are the viscosity of the ingredient, as well as whether it is a Newtonian or non-Newtonian fluid. Examples of non-Newtonian fluids are shear-thinning or shear-thickening fluids, and they require special consideration throughout the spray drying process. These properties affect everything from the batch process to atomization to cleanup.


2-    Percent solids in liquids: This factor is often abbreviated as %S, and it’s the next consideration after the rheological properties of the ingredient. The higher the %S for an ingredient, the less water will evaporate during the spray drying process. This leads to a higher production rate as well. It’s very important to check and make sure that the evaporation levels don’t exceed the capacity of the spray dryer.


3-    Specific gravity: Specific gravity is the density of the ingredient compared with the density of a standard like water or air. The specific gravity of the ingredient affects the throughput of the product. Knowing the throughput of an ingredient is very important for calculating production rates and will factor into whether, or not an ingredient’s production is financially viable. The atomization method, type of nozzle, and feed pressure all factor into the overall production rate of an ingredient.


4-    Heat sensitivity: Since spray drying uses hot air and gases to convert an ingredient into a powder, the heat sensitivity of that ingredient is crucial. Spray drying works well for heat sensitive materials, but the type of heat sensitivity is an essential factor when determining the most effective spray drying process. There are some types of heat sensitivity that will limit the potential for spray drying. For example, if liquid needs to be kept refrigerated up until the spray drying process, this makes the spray drying much less efficient. Another limitation is if the liquid needs to be heated in order to achieve the necessary viscosity for spray drying.



5-    Chemical properties: The chemical properties of any batch liquid ingredient should be considered before spray drying can begin. In particular, the pH balance of the liquid should be assessed. Liquids with a high or low pH can be corrosive, which means they have the capacity to damage the spray drying equipment if they are not handled properly. Abrasive products can also damage equipment, particularly pumps and pipes that are part of the liquid storage. Hygroscopic ingredients are very difficult to dry, whereas thermoplastic materials have problems with conveying due to a low glass transition temperature.

Ingredients can also cause safety hazards if they have a high KST, or explosion factor, a low MIE, or minimum ignition energy, or if they are highly flammable. These safety hazards are an extremely important consideration that should not be overlooked.


6-    Suspension/emulsion stability: It is common for these specialty ingredients to be either a suspension or an emulsion. A suspension is when pieces of a solid are mixed into a liquid but do not dissolve. An emulsion is when one liquid is suspended in another liquid. Another term for these is colloids. In order for these substances to be efficiently spray dried, they need to be stable. They need to be able to remain well-dispersed and homogenous, otherwise they can clog the nozzles of the spray drier or create uneven flow. This will have a very negative effect on the quality of the final product.


7-    Foaming: Some ingredients will foam when they are stimulated, which poses potential challenges for spray drying. Foaming can be managed, but it must be taken into consideration ahead of time in order for the spray drying to work effectively. When foaming isn’t properly managed, it can lead to overflow, clogged nozzles, and ingredient waste.




American Custom Drying’s Specialty Ingredients Dryer

ACD has assessed all the potential challenges that come with spray drying specialty ingredients and created a dryer that is designed to address these key factors. This dryer runs 24/7 and has several important features to make spray drying more efficient. It only requires 50 gallons of materials to run a line trial and has a maximum water evaporation capacity of over 200 pounds. This dryer uses high pressure atomization to create stable, high-quality end results. The dryer is versatile, and the atomization nozzles, optimizing quality, consistency, and production rate are all adjustable. Here are some of the key features that the Specialty Ingredients Dryer uses to create ingredients of the highest possible quality for customers.


  • Dehumidifier:The dehumidifier compensates for the fact that many ingredients are temperature sensitive. During the winter and summer months, when humidity levels are higher, drying temperatures need to be higher as well, but this can be a very limiting factor for temperature sensitive materials. Having a dehumidifier built into the dryer means that it can use lower temperatures year-round, allowing for a broader range of spray drying possibilities.


  •      Heat recovery unit:This feature takes heat from the exhaust pipe and uses it to heat the inlet air before sending it into the burner. This feature is key for a sustainable, energy efficient dryer. It decreases the overall carbon footprint of the device, and it also lowers the device’s gas usage.


  • Fluid bed:This integrated static fluid bed creates an efficient drying environment that is completely uniform. It is used as a secondary drying step. It helps to control moisture levels within the powder more efficiently, creating a stable environment for the most heat sensitive materials.


  • Dual baghouse system: This unique product reclaiming method is designed to reduce overall waste and yield loss, while maintaining the superior quality of the product and reducing the risk of contamination. With traditional reclaiming methods like wet scrubbing, there is always the possibility of product waste and or contamination as the powders are fed back through. By minimizing waste, the dual baghouse system makes the specialty ingredients dryer much more financially efficient and sustainable.


  • Clean in Place System:The CIP system on the dryer reduces cleaning times between batches for a faster changeover. It uses spray ball assembly in each section of the dryer. This saves a huge amount of time, and it also prevents cross contamination of products while spray drying. This is incredibly important for ensuring a safe, high quality end product, as well as an efficient use of time. Long cleanup times can negatively affect yield levels, so the CIP system can help to improve productivity.


Quality Control Standards

Because specialty ingredients require such attention to detail, the Specialty Ingredients Dryer uses the highest quality control standards to ensure safe results. This dryer is a certified SQF 2000 level 2. It also has been recognized in the industry globally for using a Hazard Analysis Critical Control Point food safety plan. Practitioners from SQF and HACCP are always on site. ACD makes consistent efforts to obtain ISO 9001:2008 recertification each year. They also consistently maintain their compliance with 9CFR417 and 21CFR110, which are important parts of HACCP compliance set out by the FDA.


With consumers demanding complex specialty ingredients in their food and supplements, it makes sense for food companies to outsource their production to contract manufacturers. However, it’s very important to find a contract manufacturer that specializes in spray drying, with a focus on high quality results, safety and compliance, and efficiency. Mass manufacturing of specialty ingredients is tricky, and the ideal system saves time and money while preventing waste.


American Custom Drying has positioned themselves as the best choice for companies seeking a contract manufacturer for specialty ingredients. ACD offers their unique Specialty Ingredients Dryer as well as flexible scheduling 24/7. They help clients make their specialty ingredients a reality by working with them through evaluation, line trial, and eventually commercialization. They address the unique challenges of each new ingredient to find the safest, most appropriate solution. They are one of the only contractors in the field who can offer this specialized focus on spray drying for specialty ingredients.