Malvern launches accessories for chocolate and coffee analysis

The two additions to the Mastersizer portfolio are the Chocosizer and the Funnel Sample Feeder for the Aero S.

They are designed for the Mastersizer3000 to enable measurements as part of production and quality control.

For coffee, samples for analysis are extracted at the exit of the mill/classifier so check the grind level is correct.

For chocolate, measurements may be made of intermediates (such as chocolate crumb) to confirm a process is under control, or on the final product.

Using laser diffraction particle size analysis​

Dr Paul Kippax, product manager at Malvern Instruments said the accessories make it simpler for companies to implement laser diffraction particle size analysis as a routine quality control (QC) tool.

“For coffee – particle size relates to the flavour of the brewed coffee. If the particle size is large (e.g. French roast) then a smooth coffee taste is obtained,” ​he told FoodQualityNews.

“If the coffee size is fine (espresso) then a stronger, more bitter taste is obtained. Control of the particle size is therefore important to achieve product consistency.​

“For chocolate – particle size relates to parameters which impact the consumer’s perception of the product (mouth feel – grittiness, stickiness; flavour release; fat content/incorporation) as well as to the cost of production (energy use during milling / conching; requirement to add expensive components such as cocoa butter). ​

“So, as with coffee, measurement is important in achieving product consistency at a reasonable cost.”​

Malvern said advantages of laser diffraction over traditional methods include speed, range and resolution of measurement for particles which may impact product consistency and maintenance as it is easier than sieving.

Measurement of chocolate and coffee samples​

The Mastersizer 3000 and the Funnel Sample Feeder for the Aero S dry powder disperser offer an alternative to traditional sieve analysis for routine measurement of the particle size distribution of coffee samples.

The accessory is designed for bulk measurements of coffee grounds within production and quality control and disperses coffee samples ranging up to 130ml in volume, ahead of measurement.

It speeds up and simplifies the process of introducing samples for analysis, decreasing the time required to obtain results, said the company.

The Chocosizer kit enables measurement of chocolate samples, by streamlining analytical workflow. To achieve representative particle size data chocolate must be dispersed within a suitable solvent.

It includes an external ultrasonic probe, timer and liquid dispensers, enabling efficient pre-dispersion of chocolate samples prior to measurement.

The main issues experienced in particle size analysis can be classified under two main themes - how to ensure that a good method is being used and how to ensure that users follow the correct method, said Malvern.

“For the first point the Mastersizer 3000 offers a range of functions to enable the process of sample dispersion and analysis to be followed and optimised,” ​said Dr Kippax.

“For the second point the new accessories provided for coffee and chocolate are designed to support a standard workflow for measurements, helping to reduce operator-to-operator variability in the measured particle size,” ​he said.

“In addition, the Mastersizer 3000 measurement method can be locked down in an SOP (Standard Operating Procedure) which can be loaded by an operator to ensure that the system set-up and measurement process is the same for every measurement.” ​

Other applications of the Mastersizer 3000 and Malvern’s other particle sizing technology include analysis of dairy products: quality control for milk homogenisation and development of drinks such as cream liqueurs and ice cream: measuring particle size of fat in ice cream is part of understanding its structure and ensuring product does not feel ‘oily’ or ‘fatty’, when consumed. 

Quality control for ground ingredients such as sugar, flours, flavourings, measurement of the components of sauces and looking at ground tea, as part of developing instant green tea products are other applications.