Cocoa powder is the key ingredient in many chocolate-based foodstuffs and beverages that are enjoyed by millions of people around the world. The process of producing cocoa powder and associated end products is a complex one, ranging from the pre-cleaning, pressing and alkalisation of cocoa nibs to the micronising, lecithinising and instant agglomeration of cocoa powder. The Hosokawa Group – leading experts in powder processing technology – offers comprehensive know-how and high-tech solutions to support customers every step of the way.
Starting with the nibs
First of all, it is necessary to pre-clean the cacao nibs. This can be done using the ZigZag classifier from Hosokawa Alpine. Next, batches of cacao nibs or 'broken nibs' are sterilised and homogenised ready for further processing. Hosokawa Micron's Conical Paddle Mixer (CPM) is a high-quality and efficient atmospheric vertical paddle mixer that is very popular for sterilisation and homogenisation in the traditionally no-nonsense, cost-conscious cocoa industry.
Next, the cacao nibs are alkalised to give them a better colour and milder taste in line with the end product requirements. For this process, Hosokawa Micron has designed the robust Conical Paddle Dryer (CPD) to achieve gentle yet accurate mixing even under the harsh conditions of an alkalisation process. This is possible thanks to the low friction of the single-shaft paddle rotor, combined with a well-thought-out vessel design which results in a homogeneous temperature and composition profile from top to bottom.
Cocoa press cake
After alkalisation, the nibs are roasted and wet-milled into cocoa liquor: cocoa particles suspended in cocoa butter. The cocoa butter is then pressed, which separates it into two basic components: liquid cocoa butter and cocoa press cake, which is the base component for cocoa powder. The resulting solid discs of cocoa press cake must first be pre-broken before they can be micronised into cocoa powder. Hosokawa Micron has developed a robust, reliable and low-maintenance Prebreaker for the coarse size reduction of cocoa press cake prior to fine-micronising and subsequent processing.
Cocoa powder
Once the cocoa press cake has been pre-broken, there are various options to modify the resulting cocoa powder into different finished qualities for use in end products. When used in chocolate-based confectionery products, for example, the particle size of the cocoa powder affects the so-called 'mouthfeel'. In other words, this has a significant impact on the perceived quality of the product. The Hosokawa Alpine Classifier Mill (ACM) has been optimised for the specific needs of the cocoa powder market and can micronise the pre-broken cocoa cake into ultra-fine particles of 99.5% < 75 microns or finer to achieve the optimal mouthfeel.
To smoothly process high-fat cocoa up to 26% fat content, the mill is designed with a straight outlet and a coaxial bearing to maintain an unhindered product outflow and significantly reduce clogging. Furthermore, to maximise the lifetime of the equipment, the ACM contains various wear-protected components for extra protection against the abrasive residues in the cocoa. The ACM can even be used for milling cocoa shells as well as for milling instant beverages and chocolate crumb.
Batch mixing
Batch mixing is often an important process step in the production of all kinds of cocoa-based foodstuffs and beverages. Hosokawa Micron's Nauta® conical screw mixer is well-known in the world of cocoa processing as a robust and versatile mixing solution for low-intensity mixing. It is very well suited for homogenising cocoa powders with a wide variety of product characteristics. The Nauta mixer is a highly efficient, convective mixer. Its mixing screw is suspended from an orbital arm and rotates along the inner vessel wall. This guarantees the highest level of mixing accuracy and process flexibility without product distortion.
Lecithinising
Lecithinising is a key step in the manufacture of end products such as cocoa-based drinks and pastes. In this process, (fatty) cocoa powder particles are coated with lecithin to increases their solubility in aqueous solutions. Hosokawa Micron's Vitomix ribbon screw mixer can be used to lecithinise cocoa powder in a batch operation. The design of the two conical mixing screws creates a fluidised bed in the upper part of the mixer cone that is perfect for adding liquids.
Instant agglomeration
If a continuous process is preferred, the cocoa powder can be lecithinised in Hosokawa Micron's Flexomix. In a process of high-impact continuous agglomeration, the Flexomix mixes the particles with sugar and dairy components to create homogeneous porous agglomerates that are instantly soluble thanks to their narrow particle size distribution.
The Flexomix is a compact vertical high-speed mixer with typical residence times of just a few seconds, and the innovative design comprises a flexible mixing chamber which includes an external roller massage system for self-cleaning. The agglomeration process can be optimised by changing various process parameters such as rotor speed, number and angle of the paddles and/or liquid percentage. This enables the user to adapt the process to the quality required for each application, from consumer products (low density) to vending-machine products (high density).
One-stop shop for cocoa processing technology
With 120 years of experience, the Hosokawa Group offers a wide range of innovative powder processing technology and customised solutions from a single source. The group has several research and technology centres across Europe, Japan and the USA.
The Test Centre at the Hosokawa Micron manufacturing facility in the Netherlands, comprises more than 2000m² and is fitted with 30 machines. The knowledge from the group's technical experts is combined as necessary for each project, allowing customers all over the world to benefit from a one-stop shop and a single point of contact for any issues related to the processing of cocoa powder and cocoa based products.