Solvent-free Decaffeination with Power-Ultrasound

• The conventional decaffeination process of coffee and tea requires the use of toxic solvents.
• Ultrasonic decaffeination is an effective alternative that allows to remove caffeine using a water-based extraction without the use of harsh solvents.
• Ultrasonic decaffeination is an economical, effective and green methods to produce high-quality decaffeinated coffee, tea and cocoa products.

Decaffeination with Ultrasonication

Caffeine is a water-soluble substance, so that water can be used for the removal of caffeine from coffee, tea and cocoa. Conventional decaffeination processes use a chemical as decaffeinating agent (such as methylene chloride, CO₂, or ethyl acetate) to accelerate the process. By using ultrasonic water-based extraction in combination with activated charcoal as decaffeinating agent, a decaffeinated coffee, tea or cocoa product is prepared in an organically and environmentally conscious process.

Ultrasonic Water-Based Decaffeination

The ultrasonically assisted decaffeination is an intensification process of the so-called Swiss water decaffeination process.
The ultrasonic water-based decaffeination process works using solubility and osmosis to remove caffeine from coffee beans, tea leaves and cocoa beans.
In the first stage, a batch of beans is soaked and sonicated in hot water in order to dissolve the caffeine. Ultrasonication is well known for intensifying extraction processes from botanicals. The ultrasonic cavitation opens cells and promotes mass transfer so that the caffeine is released into the water. Thereby, sonication speeds the decaffeination process significantly up.

In the second stage, the water containing the extracted molecules is drained and passes through an activated charcoal filter. The porosity of this filter is sized to only capture larger caffeine molecules, while allowing smaller oil and flavor molecules to pass through.
This means the charcoal filter holds the caffeine, whilst the filtered water contains all the smaller bioactive substances, which are known to give coffee, tea and cocoa their distinctive aroma and nutritional value.
The decaffeinated beans, which have been stripped of caffeine and flavour molecules, are discarded. The caffeine-free flavor- and polyphenol-enriched water (also known as “Green Coffee Extract”) is highly valuable and is used to remove the caffeine from a fresh batch of still caffeine-containing coffee beans.
Since this water is saturated with flavor molecules and other bioactive substances, these compounds cannot dissolve in the fresh batch of coffee beans. Thereby, only caffeine molecules are released from the coffee beans into the water and a decaffeination without removing aroma and other valuable phyto-chemicals.

High Performance Ultrasonicators

Hielscher Ultrasonics is long-time experienced in manufacturing high-power ultrasonic systems for extraction processes. Hielscher‘ ultrasonic processors are installed worldwide for applications in the food & beverage, pharma, and chemical industries.
We do not only supply high-power ultrasonic extractors, but we assist our customers also with our profound knowledge. Our customer service ranges from consultation and feasibility studies to process optimization and pilot equipment to the installation of ultrasonic systems on industrial scale.
Offering a broad range of ultrasonic processors and accessories (such as sonotrodes, flow cells and reactors), we can recommend you the most suitable system fulfilling the requirements if your process capacity and conditions. Installation and retro-fitting into existing process lines can be easily done as our ultrasonic extractors can be integrated without large modifications.
Our well-trained staff of process consultants, chemists, and engineers guide our customers towards a successful installation and operation. Hielscher‘s equipment has an outstanding robustness and requires only very low maintenance. For operational training, first commissioning, and maintenance service, we have a well-trained team which assist our customers.