In the world of food and beverage processing, fresh roast and ground (R&G) coffee flavour is renowned for its extreme sensitivity. It is negatively affected by oxidation and high temperatures can easily damage key aroma compounds as well as form undesirable heat-derived flavours. The ability to capture and retain authentic coffee flavour from the raw material is crucial in producing the high-quality coffee products desired by today’s consumers.
Natural Coffee Flavours
Traditionally, many flavour extraction technologies focus solely on capturing aromas from clear liquids, which often results in an incomplete or diluted representation of the original material. This is where Flavourtech’s Spinning Cone Column (SCC) stands apart due to its ability to capture aromas and flavours from extracts, purees, juices, and slurries containing suspended solids, e.g. milled roasted coffee beans in water. By processing raw materials as close to their raw state as possible and prior to high-temperature processing, the SCC ensures the preservation of the true character of the raw material.
With the example of coffee, it is much better to capture aroma from a coffee slurry prior to extraction than it is to use a liquid extract which has already been submitted to high temperatures and has experienced aroma loss and damage. With this in mind, Flavourtech have developed a Slurry Preparation Module that utilises specialised milling techniques to minimise flavour loss and create a uniform slurry to feed to the SCC. This module avoids much of the flavour loss seen with traditional grinding techniques in the coffee industry.
The SCC itself operates at low temperatures under vacuum and with column residence times of less than 30 seconds allowing the effective capture of volatile compounds without excessive heat exposure. The result is a recovered flavour fraction is a true and complete representation of the original material’s flavour profile. With coffee and tea in particular, the SCC performs the dual role of flavour and soluble solids extraction. That is, brewing at the same time as recovering flavour. This ensures volatile compounds are captured as soon as they are released and are then stored avoiding potential damage by subsequent processing.
The SCC is used by the world’s leading flavour houses to extract natural flavours from a variety of raw materials. In the case of coffee, these flavours are in high demand for use in the creation of various coffee-flavoured foods and beverages. The fact that the SCC has adjustable operating parameters, which can be tailored to create various flavour profiles from the one raw material, allows the development of product ranges that satisfy different geographical taste preferences.
Flavourtech’s SCC is also at the heart of the company’s Integrated Extraction System (IES). The IES is an automated processing line that includes low temperature recovery of R&G aroma from a slurry at the beginning of the process for re-addition to the final product. The IES is instrumental in helping today’s manufacturers satisfy the current consumer preference for specialty Instant coffee as well as producing high-quality Ready To Drink (RTD) and Cold Brew coffee products.
RTD and Cold Brew Coffee
Coffee slurries exiting the SCC may then be clarified using a variety of options to separate the milled beans from the aqueous extract. This clarified extract can then be used to create a full-flavoured RTD coffee with the natural flavours added back. These extracts could also be concentrated through Flavourtech’s Centritherm® evaporator to produce a high-quality concentrate for food service or at-home use.
Evaporation is another key point of aroma loss/damage during coffee processing. Traditional multi-effect evaporators operate at high temperatures and with long residence times resulting in the loss of desirable aroma compounds as well as the formation of heat-derived flavours. The Centritherm evaporator, however, is a single effect evaporator that uses low temperature (usually 50°C) and a 1 second contact time on heated surface minimising damage to the coffee’s aroma, colour and bioactives.
In the case of cold brew coffee, Flavourtech’s Rotating Disc Column (RDC), clarification module and Centritherm evaporator can be used to automate the process of producing a premium product.
Improving Instant Coffee
If the end target is instant coffee, a unique extraction technology achieving temperatures of 180 to 190°C allows for further solids extraction in only 20 minutes, compared to several hours in traditional multi-cell extractors. But, more importantly, this extraction step comes after the aroma fraction has been isolated using the SCC, meaning there is no further aroma loss or damage. Known as the RDC, this module submits a continuous flow of coffee slurry to precise temperatures, pressures and residence times for efficient and consistent extraction.
Slurry exiting the RDC is then clarified to the desired level and is usually concentrated using the Centritherm evaporator prior to being mixed with the aroma fraction and spray or freeze dried. Today, there is a preference for freeze drying as there is a noticeable flavour improvement due to the lower temperatures involved. Coupled with Flavourtech’s IES, freeze drying results in an instant powder with the highest level of R&G flavours and is the preferred option for today’s consumers.
Roasting for a Perfect Start
Finally, the roasting of coffee is a delicate balance of science and art and is a key step in crafting coffee products with the perfect aroma profile. However, as explained above, much of the Roaster’s effort and expertise is often lost in subsequent processing, with delicate coffee aromas diminishing or being lost entirely. By utilising the IES themselves, roasting companies can venture into the beverage industry with their own premium RTD or instant coffee products, preserving the essence of their craft and creating new revenue streams.
Flavourtech believes that minimising aroma loss and damage during the production of coffee-based products, be it natural flavours, RTD, cold brew or instant, is crucial in creating the high-quality products preferred by today’s consumers.
