Aseptic: Germs Stand no Chance

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Hygiene plays a decisive role in the manufacturing processes of beverages, foodstuffs and drugs. The future will see a new generation of wellness and health-conscious consumers demanding top quality products with excellent taste – in appealing and convenient packaging. This will push aseptic filling increasingly into the foreground. For producers concepts that are cost-cutting, value-adding and environmental concepts are in as high demand as ever.

Consumer research experts confirm a rise in health and nutrition-conscious consumers – a development that paves the way for added-value foodstuffs. Food producers view this as an opportunity and a means of identifying which products will generate added value thereby justifying higher prices and increasing profit margins. Health drinks in handy packaging, for example, are ideal companions and “fitness boosters” for people who are out and about. This gives the beverage industry new potential.

Strictest Hygiene for Trendy Delights

Tomorrow’s thirst-quenchers will be juices, smoothies, mineral waters, juices mixed with sparkling water, near-water and milk drinks. The large number of fashionable drinks – such as sport, energy, wellness drinks, tea, yoghurt beverages and milkshakes – must fulfil the needs of this health-conscious generation of shoppers if they want to withstand competitive pressure at all. Many of these products are susceptible to microbes and therefore require aseptic filling. To stand out from the huge number of rival products, innovations are required. Furthermore, producers are under pressure to make manufacturing more efficient. Those wanting to be successful as food producers on the international market will require solutions that both fulfil consumers’ and retailers’ requirements and improve margins at the same time. In turn the packaging industry must be flexible and efficient. This is what makes companies competitive and keeps the system costs stable. When developing new machinery and plants the principal imperative is to live up to food manufacturers’ expectations and to increase actual output. Obviously, the strictest hygiene is also called for here. Likewise, aseptic filling faces ever new requirements due to the continuous development of new container closures and shapes thereby injecting innovation into the market. Contamination by undesirable micro-organisms can entail substantial quality losses and – in a worst-case scenario – even health hazards for the consumer.

Cold Aseptic – Buzzword for Sensitive Beverage Filling

The buzzword in today’s soft drinks industry is “cold aseptic beverage filling”. Viewed with scepticism only a few years back, cold aseptic filling using single-use plastic bottles is now on course for international success. On the one hand, it requires no use of preservatives, thereby cutting costs in the beverage industry, and on the other, it brings added health benefits to consumers. Furthermore, taste, aroma and colour are retained since the process used is a particularly gentle one. Today, there are two different approaches to cold aseptic beverage filling on the market: the so-called dry sterilisation process and wet sterilisation. Both processes are said to be identical in terms of safety. While some are convinced of dry sterilisation since it brings further cost cuts thanks to savings in rinsing water for bottles and closures, others favour wet sterilisation – especially because of the traditional bottle and closure rinsing process. In general, preference should be given to a wet rinsing process if the bottles and closures fed into the sterilisation process in the ACD block are not guaranteed to be 100% free of any particles, liquids or condensate. This is generally the case when bottles and closures come from an external supplier and the ACF block is not immediately fed by the upstream blow-moulding machine.

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Some like it Hot

The shelf life of still beverages can also be extended by heating them for filling purposes. This process is particularly suited for CO2-free fruit and vegetable juices, for coffee, tea and soya drinks. Thanks to the high filling temperature detrimental germs are killed and certain enzymes are deactivated. Here the addition of preservatives is not required either. Hot filling is suitable for glass bottles, special PET bottles and tins.

Longer Shelf Life thanks to Degermination

In the food sector two major processes for packaging materials and substrate degermination have crystallised: hydrogen peroxide (H2O2) and steam. The high requirements of aseptic packaging can be achieved with both technologies – for liquid or highly viscous foodstuffs even containing lumps. For packaging fresh produce such as yoghurt there is a tunnel cover to which sterile air is applied. For packaging products stored outside the cold chain, additional steam sterilisation of bottom and lid films can be used. These aseptic systems use saturated steam for degerminating the films: in any case steam is available, pollutant-free, at most dairy and food manufacturing sites. The degerminating effect is based on the effect of moist heat only. Unlike chemical agents steam leaves no residues in the product, nor does it have any detrimental effects on operators.

The other way to protect any type of dessert (e.g. yoghurt, pudding and mousse) against recontamination by infected outside air to ensure safe packaging material sterilisation is the germ-killing effect of hydrogen peroxide with its great oxidative potential. A safe germicidal method for products distributed via the cold chain consists of applying hydrogen peroxide steam to cups and lids since this steam accumulates on the inside of the packaging material like a fine condensate film. This film is then heated to a temperature high enough to accelerate the sterilisation effect using hot air. However, for products expected to be non-perishable over an extended period of time even outside the cold chain the manufacturing process must be free of any micro-organisms including bacterial spores.

Strictest Purity for the Pharmaceuticals Industry

Needless to say, the manufacturing of drugs also requires a high degree of quality management and safety awareness. Under no circumstances may drugs be contaminated by undesirable foreign bodies during the production process and there must be no microbial impurities present. The cleaning concept and cleaning of the fluidized bed production lines used by solid drugs manufacturers are deemed a priority in the pharmaceuticals industry. With current analytical devices even very small amounts of active agents can be detected: should the purity measures in a company not be failsafe and a preparation thus become contaminated by foreign matter this would constitute a far-reaching infringement of cGMP (current Good Manufacturing Practice). In the pharmaceutical industry solid drug manufacturing plants can be washed semi-automatically (in place) or fully automatically (WiP/Clean in Place). These options should already be taken into consideration in the early stages of plant engineering since washing quality is directly linked to plant design.

In all areas it is key to employ machinery and technology that is suited to the product. The required degermination performance of a packaging machine depends on its application. Factors impacting this include the perishability of the product, the desired best-before date, the distribution channel, the germ load of the product, the initial germ load of the packaging material or the germ load produced by machines. The on-going development of new products on the market also continually changes the requirements for modern plants. When selecting the right type of plant consistent implementation of hygienic-design criteria needs to be respected first and foremost. Depending on the application the machines must then be equipped with added functionalities to improve product protection. The VDMA Food Processing and Packaging Machinery Association distinguishes between five different categories of liquid and highly viscous foodstuffs. So far, the VDMA has issued eleven publications on the topic “Aseptic and Low-Germ Filling of Liquid and Highly Viscous Foodstuffs”. These are available for download in German and English from www.vdma.org (Databases/Publications).

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