Food powders are a diverse group of particulates in the size range of roughly 50 to 1000 μm (for example, flour, sugar, spices, instant beverages, soup mixes, etc.). The physical properties of food powders, such as cohesion, density, flowability, mechanical strength, compressability, and segregation tendency, are influenced by composition, microstructure, particle size, and particle size distribution.
This blog post explains how particle size distribution in food powders impacts their properties and quality.
Why Does Particle Size Distribution in Food Powders Matter?
The bulk density, compressibility, and flowability of a food powder are highly dependent on particle size and particle size distribution. The following table highlights how particle size distribution in food powders impacts the properties and quality.
| Effect of Particle Size Distribution in Food Powders | ||
|---|---|---|
| Properties | Effect | Quality |
| Bulk density, or how densely the powder packs together. | A narrower particle size distribution leads to lower bulk density or lower weight per unit volume. A wider particle size distribution results in higher bulk density, which means a dense powder. |
Bulk density, influenced by particle size distribution, impacts the flowability of food powders during transport, storage, or processing. |
| Compressibility, or how much a powder decreases in volume under pressure. | A narrower particle size distribution results in lower compressibility. A powder with a wider particle size distribution generally exhibits higher compressibility. |
Compressibility of a food powder impacts its flowability. Notably, powders with good compressibility tend to have higher bulk densities. |
| Flowability, or a powder’s capacity to move or flow easily. | A narrower particle size distribution tends to improve the flowability of a powder. A wider particle size distribution often leads to poor flowability due to increased inter-particle forces and friction. |
While increased flowability enhances powder quality through better mixing and packaging, excessive flowability can cause inconsistent product performance. |
Spray Drying: A Preferred Method for Uniform Particle Size Distribution in Food Powders
A uniform particle size distribution is critical for optimal handling, processing, and quality control of food powders. Spray drying is a trusted technique to produce food powders with controlled particle size (in the range of 5 μm to 10 μm with different morphologies) and distribution.
The properties of the feed material, feed rate, drying temperature, the type of atomizer used, and atomization pressure help optimize the droplet size and final particle size and distribution. For example, the particle size and distribution of dry milk powder are significantly influenced by spray drying conditions. Spray drying achieves uniform particle size distribution through process parameters, such as:
- Temperature: The high inlet temperature (180°C to 250°C) and a relatively low outlet temperature (80°C to 100°C) optimize drying rate and preserve the integrity and quality of the ingredient.
- Atomization and droplet size. Dryer, nozzle, and atomization pressure parameters influence particle drying time and particle properties, including size distribution.
- Heat exposure time: 12-30 seconds of rapid spray drying helps achieve complete drying with uniform particle formation and distribution, without over-processing of the ingredient.
- Feed rate management: Customized feed rate during spray drying determines droplet size and powder characteristics such as particle size, shape, and distribution.
Develop High Quality Powders With Advanced Powder Dynamics
Advanced Powder Dynamics is redefining spray drying with proprietary Dynamic Atomization Technology (DAT) that provides a more controlled environment for particle formation. Our patented technology enables customizing nozzle geometry and nozzle operating parameters, as well as dryer operating parameters (air flow rate and pressure) to create smaller and more uniform powder particles and particle size distribution.
Our expertise in spray drying atomization techniques helps us fine-tune particle shape, size, surface, and distribution to develop and scale food powders that are stable, consistent, and high-performance.
Want to learn more about how Advanced Powder Dynamics can help you with particle size reduction methods? Contact us or call (928) 492-4040.
William West, a Harvard MBA, has a proven track record of scaling businesses, having expanded HID Global Corporation’s revenue from $200 million to $1 billion through strategic acquisitions. As Co-founder, CFO, and COO at ACRE, LLC, he transformed the company into a $350 million global leader. His vision now drives Tesseract Life Sciences’ mission to redefine health with science-backed innovations.