Texture Analysis & Flowability of Coffee: Instant, Ground and Bean

Coffee is one of the most traded agricultural commodities in the world. According to Statista, revenue in the coffee market worldwide in 2020 amounts to USD 44.8 billion, and is expected to rise by 5% each year up to 2025.

It reaches the consumer in many different forms, from a creamy latte in a hipster coffee shop to a more basic instant. The three main forms that reach the supermarket shelf, however, are whole beans, ground and instant granules. This blog post covers the Texture Analysis techniques used by manufacturers in search of a perfect brew.

Texture Analysis in Action 2: Powder Vertical Shear Rig

Anyone who has handled powders has almost certainly come across a clogged hopper, and will know that this is caused by caking, arching or rat-holing. 

To measure the tendency of a powder to show these properties, the main property to consider is the powder’s bulk resistance to the initiation of flow. 

This helps to imitate the consolidation that occurs under the powder’s own weight when the outlet is shut and the feeder is switched off. It is when the outlet is opened and the feeder started again that the blockages can build up.

Texture Analysis in Action 2: Indexable Powder Compaction Rigs

Indexable Powder Compaction Rig (A/IPC0.5)

Many years ago we introduced two variants of Powder Compaction Rig (high tolerance and low tolerance) suited to high force applications. 

However, there is a need for powder compaction testing of similar sample volumes at lower compaction forces than the existing methods that require a TA.HDplus Texture Analyser. 

As such, we have developed two low force powder compaction fixtures – offering a choice of volumes for 10 samples – to provide indexable testing up to 50kg.f and to increase  useability and efficiency.

Texture Analysis in Action 2: Unconfined Yield Stress Rig

Stable Micro Systems have launched the Unconfined Yield Stress Rig for the measurement of powder flowability.

In industries that handle powders on a regular basis it is very important to understand how a powder or granular material responds to pressure. In storage, the weight of powder in a container exerts pressure on the particles at the bottom.

If the powder has good flow behaviour it will not consolidate and will flow out of the silo or hopper without sticking – this is very desirable. The longer a powder is stored for, the more likely it is to form a cake in its hopper and refuse to flow without further assistance.

New method for measuring Unconfined Yield Strength of Powder using your existing Texture Analyser

Stable Micro Systems have launched the Unconfined Yield Stress Rig for the measurement of powder flowability.

In industries that handle powders on a regular basis it is very important to understand how a powder or granular material responds to pressure. In storage, the weight of powder in a container exerts pressure on the particles at the bottom. If the powder has good flow behaviour it will not consolidate and will flow out of the silo or hopper without sticking – this is very desirable. The longer a powder is stored for, the more likely it is to form a cake in its hopper and refuse to flow without further assistance.

Texture Analysis in Action: the Powder Compaction Rig

Powder Compaction Rigs:
Low Tolerance (left); High Tolerance (right)

The Stable Micro Systems POWDER COMPACTION RIG is available in two variants.

The High Tolerance Powder Compaction Rig (A/PCRS) is suited to high force applications where the punch/die clearance is critical; this fixture is auto-aligned using a universal adapter.

The Low Tolerance Powder Compaction Rig (A/PCR) is suited to other powder compaction applications such as assessing granule friability, where the punch/die clearance is less critical.

Texture Analysis in Action: the Powder Flow Analyser

The POWDER FLOW ANALYSER (PFA/PL) is an accurate and reliable method of measuring the flow characteristics of powders.  

It can be rapidly fitted to a Stable Micro Systems plus series Texture Analyser, enabling manufacturers to assess and avoid typical problems such as batch and source variation of ingredients, caking during storage/transportation and problems with discharging from hoppers or bins.

The Powder Flow Analyser is supplied with library tests so operators can start testing quickly and conveniently after straightforward installation and calibration. Users can, however, fully program the instrument to carry out slicing, shearing, compressing, compacting and aerating cycles in any combination.

Texture Analysis in action: the Granule Compaction Rig

The GRANULE COMPACTION RIG (HDP/GCR*) 

Granule hardness/compressibility testing is important to provide an indicator of the tabletting potential of some materials, or a measure of friability or compaction strength of granules.   

Where granules are irregular in form, the testing of single granules is discouraged as repeatability is compromised. In this instance, the testing of a fixed area of sample creates an averaging effect and improves the repeatability of the results.