thermal processing From April 2019

How to reduce costs and improve quality by optimising thermal processing

What is thermal processing?
Thermal processing is an important method of food preservation, controlling the presence of microbial spoilage organisms in food stuffs and ensuring products are safe. A growing range of food products is preserved using thermal technologies, ranging from sterilisation, such as canning and ultra high temperature (UHT) processing, to milder pasteurisation heat treatments, such as high temperature short time (HTST), steam/air oven cooking and pasteurisation tunnels.

Why optimise thermal processing?
Preservation of a food’s nutritional and sensory attributes during heat processing is very important for quality and consumer acceptance of the product. As the thermal stability of nutrients or quality attributes often differ from pathogenic organisms, it can be challenging to find an optimal thermal process, but it is possible.

Process optimisation, i.e. a reduction in over-processing, can aid the retention of natural or added quality components such as colour, vitamins and antioxidants after heating. It can also extend product shelf-life, increase product throughput and reduce energy consumption of equipment.

How can thermal processing be optimised for quality?
Thermal processes are primarily applied to assure product safety. The time and temperature of the treatment can be tailored to optimise quality - such as flavour, colour, texture and vitamin or nutrient levels - without compromising safety. Maximising the efficiency of the heat transfer is key when optimising a thermal process for quality reasons. There are several factors that affect the rate of heat transfer, including, heating method, packaging type and product composition. Adjusting any of these factors to improve the rate of heat transfer can aid quality retention - and sometimes a small adjustment can have a large impact.

Processes can be optimised to increase quality with the help of theoretical calculations and modelling software. These tools provide insights into heating effects on product properties without extensive trial work. For example, lower temperatures applied for longer periods may improve quality for some products, but higher temperatures applied for shorter periods of time may benefit others.

When should I optimise my thermal process?
Quality optimisation work can be an easy add-on to a thermal process validation project. Validation checks that food safety requirements are met but optimising the process can ensure that the product isn’t over processed, potentially reducing time and energy requirements. If you’re looking to improve existing processes, or to explore the potential of new products and process equipment, we can help you optimise your existing processes using calculations, modelling or with on-site trial work.

Contact: David Whittaker
+44(0)1386 842031

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