Debunking the myths about food pasteurisation

Pasteurisation has been established as a key method of destroying pathogenic bacteria in the food and drink industry since is invention in the middle of the nineteenth century, although the origins of heating wine for preservation go back to China in the 1100s. However, as food and drink processing becomes more complex and food chains longer, the importance of pasteurisation has increased.

At the same time, the technology has also improved, with developments in the equipment used for both  for High Temperature, Short Time (HTST) and Low Temperature, Long Time (LTLT) methods. While simple plate heat exchangers may still be suitable for the pasteurisation of simple fluids such as milk and fruit juices, more textured and viscous products, such as cooking sauces, creams and curds will require different solutions in order to maintain their quality and texture. Here we dispel seven popular myths about food pasteurisation

Myth 1: Pasteurisation is expensive
While the exact costs will vary with each installation, there is no doubt that there is a capital cost to pasteurisation. However,  compared with the potential losses due to food spoilage, or worse, a food safety incident, these costs are insignificant. In the US, the costs of recalling food products have been shown to average $10 million, before accounting for brand damage. Closer to home, microbial contamination resulted in 59 product recalls in Australia between 2014 and 2016. Furthermore, Food Standards Australia New Zealand reports that  Listeria monocytogenes, Salmonella and  E. coli are the three micro-organisms most commonly associated with microbial food recalls in Australia, while those products most recalled are meat and dairy items.

Against these potential costs, the capital cost of a corrugated tube heat exchanger based pasteurisation system is a sound investment. Alongside the capital costs, the running costs of a pasteurisation unit need to be considered. Heat exchangers and  pasteurisation units made by HRS Heat Exchangers are designed to reduce fouling and maintenance, while our wide range of heat recovery options mean that energy costs are kept to a minimum.

Myth 2: Pasteurisation is too complex
Pasteurisation itself is a relatively simple process. It requires that a material is held for a certain time at a certain temperature in order to kill micro-organisms. There is no doubt that pasteurisation adds an additional step into the overall manufacturing process, but if well-designed it should not slow down throughput or place additional management burdens on the plant. The use of continuous pasteurisation systems mean that the process is simple and the potential for product damage or change in quality is minimised.

Myth 3: Pasteurisation is only suitable for simple fluid materials
Pasteurisation can be used on a wide variety of liquid and semi-liquid materials. While simple Newtonian fluids will be the easiest to work with, and can often be effectively pasteurised with a simple plate heat exchanger, there are solutions for almost any material. HRS innovations, such as the use of corrugated tube and scraped surface heat exchangers, means the company can deal with anything from viscous fluids requiring gentle handling or with low rates of heat transfer, to complex mixtures, such as curd cheese, which could otherwise foul the heat exchanger, reducing thermal efficiency and requiring regular cleaning and  maintenance.

Myth 4: Pasteurisation requires a lot of energy
The amount of energy used in food pasteurisation is highly variable depending on the process used, the nature of the material being treated and the heat exchanger used. The bulk of any energy requirement is used to raise the temperature of the foodstuff.

Traditional pasteurisation units simply dump this heat afterwards, meaning they are incredibly wasteful and inefficient. Where possible, HRS heat exchangers recapture the heat and use it again, making them up to 70 per cent more efficient than some traditional systems.

Myth 5: Pasteurisation equipment is high maintenance
The use of corrugated tubes, together with integrated cleaning-in-process (CIP), minimises the amount of fouling and therefore the amount of cleaning necessary to maintain the efficiency of HRS pasteurisation systems. The careful design of static tubes also helps keep down production (and therefore purchase) costs.

Myth 6: You cannot pasteurise viscous fluids
Subjecting viscous and non-Newtonian fluids, such as cooking sauces, to shear stress during the manufacturing process can damage  the quality and texture of the material, which may preclude the use of certain designs of heat exchanger for pasteurisation. However, by choosing a system such as the HRS Unicus scraped surface heat exchanger, which prevents fouling while maintaining  relatively low pressure, such unwanted effects can be overcome.

Myth 7: Pasteurisation is the same as sterilisation
Unlike sterilisation, pasteurisation does not completely eliminate micro-organisms which may be present in the foodstuff. Pasteurisation reduces the microbial load by a significant factor (for example by 5-logs), which in normal circumstances reduces contaminating pathogens to a level at which they do not pose a hazard. Pasteurisation need not be overly onerous or detrimental to the quality of the product. Certainly, with the correct choice of equipment, pasteurisation does not need to have a negative effect on plant throughput or efficiency and a well-designed system incorporating heat regeneration and corrugated tubes should enhance the overall facility, helping to add flexibility to your business.

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