Production of Premium Quality Tea & Coffee Extracts

Interest in and consumption of convenience coffee and tea products is increasing world wide. The Ready-To-Drink (RTD) canned or bottled tea and coffee, liquid tea and coffee dispensing machine markets are all rapidly expanding as consumers look at alternatives to fizzy pop drinks. 

Presently one of the major problems with many tea & coffee liquids and concentrates available is that they are poor substitutes for a fresh brew. The traditional manufacturing techniques used for many of these products fail to retain any of the distinctive tea or coffee aroma that is often desired by consumers. 

FT Technologies has developed the modular Integrated Extraction System (IES) for  the production of premium liquid tea & coffee extracts and concentrates. Products made utilising the IES can now provide all of the fresh brewed flavour of the original tea leaf or coffee bean.

Two key characteristics that the IES offers are:

1. Its ability to capture and preserve key flavour notes for inclusion into the final extract. Aromatic compounds of fresh-brewed roast and ground coffee, or distinctive varietal characteristics exclusive to tea blends, are captured at their peak quality, neither damaged nor destroyed.

2. Its flexibility as a continuous modular system. The unmatched flexibility of this modular approach means that some of the individual modules can actually be combined with existing processes (see diagram below for module details).

At the core of the system is the Spinning Cone Column (SCC), now widely acknowledged as the world’s premier flavour recovery technology. The SCC is the fastest, most efficient method in the world for the capture and preservation of volatile flavour components, from all kinds of liquid and slurry substances.

When a slurry of coffee beans or tea leaves and water is introduced into the SCC, the beverage is literally brewed within the closed system. The SCC effectively performs the dual roles of flavour extraction and soluble-solids extraction simultaneously, thus avoiding intermediate flavour loss or degradation.

Also unique in the process is the use of the Centritherm® evaporator, which uses Spinning Cone technology to effect rapid evaporation with low thermal impact. This centrifugal thin film evaporator further enhances the retention of flavour producing premium tea and coffee extracts and concentrates.

Click here to find out more about the Integrated Extraction System (IES)

Coffee Flavour and Essences
It is possible to collect an intense, fresh-roasted, coffee character by literally brewing the coffee in the SCC. A slurry of cold water and roast and ground coffee is passed through the SCC. The presence of the coffee solids greatly enhances the recovery, in terms of both quality and quantity, of volatile compounds.

Flavour houses around the globe process coffee slurries in the SCC to produce the world's finest coffee flavours.

Coffee Slurry Processing
The SCC can process feed streams with high proportions of suspended solids. If a slurry of roast and ground coffee beans and cold water is fed into the SCC, it is possible to capture all of the coffee aroma, including top-notes, reminiscent of a fresh brew.

The IES uses slurry processing to produce a final coffee extract which is as good as, if not better, than freshly brewed coffee. The GC analysis below shows a comparison between a commercially available coffee extract and one produced by the IES. The high concentration of volatile compounds and dominance of "front-end" characters in the IES sample is attributable to the collection of the coffee flavour from a slurry of fresh-roasted coffee.

The Centritherm evaporator used in the IES process is currently utilised around the world for production of both liquid and soluble coffees. It may be used to concentrate coffee extracts up to 70° Brix (62.0% Soluble Solids) in two passes.

Tea Flavours and Essences
It is possible to collect the delicate, floral character of freshly brewed tea by literally brewing the tea in the SCC. A slurry of cold water and tea leaves is passed through the SCC. The presence of the tea solids greatly enhances the recovery, in terms of both quality and quantity, of volatile compounds. 
 
Tea Slurry Processing
Similar to the process for coffee, the SCC can process a slurry of milled tea leaves and cold water in order to capture all of the delicate, floral notes distinctive of varietal teas.

The IES uses slurry processing to produce a tea extract which is possibly better than a fresh brew. The GC analysis table below shows a comparison between a commercially available tea extract and one produced by the IES. The concentration of volatile compounds, particularly the "top-notes", is much higher in the IES sample. In some cases by greater than a factor of ten!
 

 
Soluble (Instant) Tea Powder
Traditional soluble tea manufacturing processes lose much of the typical tea flavour during the production of the soluble product. Major flavour losses occur during extraction, concentration and drying. Often soluble teas do not contain any of the floral character distinctive of a fresh brew.

The first step in the IES process is to remove the flavour from the tea as it is being brewed. The flavour is then stored under optimum conditions, protecting the delicate, varietal "top-notes" from certain damage or loss during subsequent soluble solids extraction or extract concentration.

There are two options for reincorporation of the flavour; it may be added to the concentrated extract immediately prior to spray or freeze drying (although it is inevitable that some flavour will be lost during drying) or it can be added during reconstitution of the powder.

High Quality Tea Concentrates
Both green and black tea extracts are extremely sensitive to heat. Exposure to elevated temperatures for prolonged periods initiates changes to the colour and flavour of the extract as well as degrading health promoting “active ingredients”. In extreme cases, this “thermal impact” can cause caramelisation of naturally occurring sugars within the tea extract. To ensure a high quality concentrate, tea extract must not be exposed to high temperatures for any longer than is absolutely necessary.

The Centritherm evaporator used in the IES process can be used for concentrating tea extracts up to 45 to 50% soluble solids. The concentrate produced is of extremely high quality - preserving colour, flavour and active ingredients - as the thermal impact experienced by the product is negligible due to the Centritherm evaporator’s short residence times and low evaporation temperatures.

Key benefits of the Centritherm evaporator include:

• High concentrations readily achievable (without product recycle).
• Viscous tea concentrate (up to 45 to 50% DS) easily handled.
• Exceptionally short product residence times (about 1 second on the heating surface).
• Low operating temperatures (around 50°C).
• Range of models to suit any capacity
• Negligible thermal impact resulting in high quality concentrate

Centritherm evaporators are used around the world for the production of quality, concentrated tea and coffee extracts for use in RTD products.

Click here to find out more about the Centritherm evaporator.