Jordan Talmadge, PPG’s global commercial director, silicas, recently spoke to FOOD ENGINEERING about the role silicas can play in preventing caking and optimizing the flow characteristics of food products, as well as improving product performance and manufacturing productivity.

FE: What are the major applications for silicas in food manufacturing?

Jordan Talmadge: Precipitated silica products serve many powdered, granulated, emulsified or grated food products to prevent caking, optimize the flow characteristics of food products and improve product performance and manufacturing productivity. Common applications include fruit and vegetable extracts, powdered beverages, instant soups, protein powders, cake mixes, spices, nutrients, preservatives and other constituent materials.

Due to its excellent absorbency, the use of silica in food manufacturing leads to shorter mixing times and enables processing efficiency through smoother ingredient blending and less caking in screens, hoppers, conveyors, spray dryers and machinery. Its large loading capacity, or the ability to absorb high volumes of liquid, also allows for the creation of concentrated products.

FE: How can silicas be used in dry liquid concentrate applications?

JT: Dry liquid concentrates (DLCs) require carrier agents to convert liquids into dry powders. Precipitated silicas are effective carriers due to their high loading capacity.

Precipitated silicas act as porous carriers that absorb liquids to create free-flowing powders and DLCs.

Silicas are an important part of many powdered and granulated food and animal nutrition products, and enable highly accurate measuring and dosing, particularly in applications utilizing sticky and high-viscosity liquids. 

FE: What production benefits can silicas provide manufacturers?

JT: Silicas are versatile and highly efficient as carrying agents, providing production and transportation advantages over other food additives. With widespread applications as a free-flow/anti-caking agent, silicas are commonly used by industrial food manufacturers to convert difficult-to-handle liquids into powdered liquids or dry liquid concentrates to improve process efficiency or product performance in products like spices, seasonings, drink mixes and animal feeds.

PPG recently conducted new research to compare the carrying capacity and performance of silica compared to alternative maltodextrin. The data shows that precipitated silica has a higher carrying capacity than maltodextrin. This increased capacity offers performance advantages including increased throughput and efficiency for manufacturers, creating cost-saving opportunities throughout the production processes.

In terms of sustainable transportation practices, PPG is the first silicas manufacturer in North America that is now able ship directly in bulk vessels such as silo trucks, which eliminates transloading, or the transfer of goods from one mode of transportation to another en route to their ultimate destination.

FE: Specifically, how can silicas affect flow rate?

JT: Precipitated silica products encapsulate powder particles and absorb ambient liquids, oils and fats from the surface of host powders to keep them from agglomerating. The ability to prevent clumping makes precipitated silica enhance the processes of manufacturing automation including the handling, storage and controlled dosing of powdered food ingredients in process machinery, such as conveyors and drying, mixing and screening equipment.

FE: What role does particle size play in manufacturers’ use of silicas?

JT: When selecting a carrying agent, manufacturers must consider several important factors. The properties of the carrier and the liquid can affect the finished product’s taste and consistency.

First, the liquid’s viscosity can make the blending process more difficult. The carrier agent must have a suitable particle size and carrying capacity to absorb the liquid and maintain it as a free-flowing powder. Additionally, if the powder is prone to caking, it can clog screens, hoppers and other machinery, as well as form clumps in the final packaging that impact the end user experience. Silica can carry large amounts of liquid at various particle sizes.

Particle size also affects the product’s mouthfeel; powdered beverages require fine particles to prevent a grainy texture, while sauces and cake mixes can tolerate larger particles.

FE: How can silicas be used to support product shipping in a variety of environmental conditions?

JT: For food service companies, contract blenders and manufacturers, silicas provide a technical solution to save time, process costs and storage space. Their high porosity and excellent absorption make them an efficient carrying agent that supports streamlined production and transportation operations.

Food manufacturers can experience a number of logistics benefits through the use of silicas. Dry powders, created with silica, require less temperature and climate control than liquids. Smaller, concentrated products can reduce shipping costs and lessen the overall carbon footprint of the manufacturer.

Additionally, PPG can now transfer our Flo-Gard silica products for food and animal nutrition customers directly from a production facility into a bulk silo truck for transportation to its destination. Compared to incumbent methods of importing materials in sacks to be transloaded into bulk trucks to move to production locations, this latest progression in supply chain logistics reduces the risk of contamination of the product; reduces shipping times (from about four months to less than a month) to improve inventory and planning; reduces GHG emissions; and ultimately lowers costs for the customer.

FE: Are there any challenges associated with incorporating silicas into manufacturing processes?

JT: For blenders and manufacturers who are using maltodextrin and want to convert to precipitated silica, the transition is straightforward. Silicas can be used in standard commercial hoppers, conveyors, ribbon blenders, mixers, spray dryers and machinery. No new equipment or additional investment is needed to incorporate silica into existing operations. 

FE: Is there anything else you’d like to add?

JT: Precipitated silicas have been used extensively as free-flow and anti-caking agents, but they are also very effective as carrying agents due to their due to their high surface area and porous structure. Silica products consistently demonstrate their capacity and versatility and help manufacturers increase production efficiency by achieving higher additive concentrations and greater storage and transportation flexibility.