Directly injecting steam as a means of sterilising and diluting liquid drink products is a well-established technique for beverages such as plant-based milk products, which are experiencing a boost in popularity. According to a report by Mintel1, sales of vegan-friendly, plant-based milks have surged 10% over the past two years, and it is now the choice for almost 25% of Britons. In response to this increased customer demand, HRS Heat Exchangers has added a new Direct Steam Injection System to its established range of pasteurisation and sterilisation systems.
The benefit of sterilising using direct steam injection is the speed of the process, with sterilisation temperatures of 100°C to 145°C. being reached in around a second, much quicker than the fastest heat exchanger systems. For products such as plant milks, this rapid heating prevents cooking of the product and formation of caramel-type compounds which can darken the product or produce unwanted flavours.
Some products, such as oat milk, also benefit from the additional dilution with water which the steam injection provides. In most cases, however the water which is added during the steam injection process needs to be removed from the end product. This is normally achieved using flash evaporation to remove excess steam and help cool the product, but there is a danger that volatile aromatic compounds can be lost, which could have a negative impact on certain products, such as fruit juices. For this reason, not all products are suitable for steam injection.
For products where direct steam injection is desirable, HRS Heat Exchangers has introduced the HRS DSI Series, which injects food grade steam into liquid products, providing an instant increase in the thermal process.