Process technology for soft drinks

According to forecasts, around 500 billion litres of soft, carbonated and still beverages, juices, water and new drinks will be manufactured and bottled by 2009 — up around 10% on 2006. Demand for the process technology to produce them is correspondingly high.

Complex job: everything must fit together

Process technology is a complex affair. It comprises all the processes from raw material acceptance, storage, transport, mixing, carbonating and heating technologies to cleaning, disinfecting and sterilising procedures. The top priority in all procedures today is the highest possible product quality, which is reflected in the call for products to be as natural as possible, among other things. At the same time, the machinery and systems are required to be extremely precise and reliable, delivering largely loss-free operation. Highly efficient compact and space-saving design achieved through optimum systems effectiveness is another stipulation.

In particular, the ever shorter product cycles and the resulting wide product ranges make great demands on the versatility of processing systems, and also on their technological sophistication and compatibility with the subsequent filling operation. Everything must fit together. The level of automation also has to be high, and electronic recording and archiving of all data relevant to the processes is required for traceability.

For this reason, the trend is ever more towards complete installations through one provider, or integration of the production process into an integrated plant concept.

Trend towards aseptic

Another trend that will continue is aseptic bottling. More and more beverages are being bottled aseptically to enhance product protection and naturally extend shelf life by largely excluding unwanted microorganisms and oxygen. Of course, the prerequisite for this is an aseptic manufacturing process and appropriate process technology, because every chain is only as strong as its weakest link.

Working aseptically requires a profound knowledge of the processes and the hygienically correct construction of the production systems using efficient, fully automated cleaning processes. Sensitive products in particular — for example, energy and sports drinks, fruit juices, juice drinks and flavoured waters and much more — need maximum microbiological safety in these respects. Such products require aseptic valve technology, water treatment systems, sterile filters, UHT systems for the products and sterile tanks. The requirements of process technology are growing with the wishes of the consumer for ever newer, fresher and more natural drinks.

Water treatment

Soft drinks all start with water, whether it is for bottling soft drinks, new-age beverages or in the form of mineral water itself. In view of the extreme water shortages in some parts of the world, the impurity of water and further cost increases in water, or rather wastewater treatment. Well or spring water is generally de-ionised, if required demineralised, softened, filtered, if necessary degassed and decontaminated or ozonised. By degassing the water first, the remaining O₂ content is reduced to a minimum, enhancing the flavour stability and shelf life of the product.

Different filter systems are suitable for removing pulp and microorganisms, colloids, fine particles and organic material, and also for eliminating substances that might produce a strange odour or taste. These include cartridge filters, membrane filtration systems such as reverse osmosis and nanofiltration, particle filter or sterile filtration, plus processes such as UV decontamination.

With or without syrup room

During the production process of soft drinks, the components of the drinks are mixed before bottling. Many soft drinks contain the basic ingredient and components such as liquid sugar, flavour or citric acid, or a syrup made from these ingredients. The components are processed in a mixing procedure in the required ratio of water to the finished drink. Electronic recipe management in the syrup room allows a high level of automation and consistent quality assurance of the products.

In general, it is possible to work with or without a syrup room. If liquid sugar and basic components are already pre-dosed from the syrup room, a two-component mixing system is adequate in the bottling hall, in which only water is added to the syrup, after which the beverage is ready.

On the other hand, the syrup kitchen can be dispensed with completely if a three-component or multiple mixer is used before the filler. Such a beverage mixing system allows either the three components of the finished drink — water, syrup and the basic ingredient — to be mixed or the elements of the basic components such as flavour, acidifier or concentrate to be processed direct.

The Brix value (indirect determination of the sugar content) is constantly monitored and, if necessary, the CO₂ content adjusted.

Thermal preservation

Another essential stage in preserving soft drinks is short-term heating, a short and gentle heating in a temperature range from 70 to 80ºC for 15 to 30 s. It ensures the reliable elimination of microorganisms and the inactivation of enzymes to the required extent. Short-term heating systems with plate heat exchangers are used for pasteurising lemonades, non-carbonated beverages and pulp-free juices, while shell and tube heat exchangers are necessary for juices containing pulp. CIP and SIP systems are an equally important component in process technology. Cleaning in place and sterilisation in place are now indispensable prerequisites in every bottling plant.

Individual designs

A design for a plant for water or juice treatment or soft drinks is always dependent on the respective requirements on the plant, such as diversity of products, level of automation, necessary versatility, the manner of preparing the drinks’ components and the required form of quality management.

A general trend is also obvious in processing technology for water, soft drinks and juice: bottling companies want an increase in integrated solutions that are optimally designed and set up by one single contact, while at the same time being able to use components from different manufacturers.