The so-called novel, new, and emerging non-thermal (and thermal) processing technology space is full of exciting approaches to combat foodborne diseases and spoilage. Food microbiologist Dr Philip Button writes. This article was first published in Food & Drink Business September/October 2020.
New food processing techniques are a mix of old and new, but the common thread is they potentially offer new ways to combat age-old (bacterial) problems.
High pressure processing (HPP), ozonation and pulsed electric field (PEF) all have their origins late in the 19th Century.
For example, ozonation originated more than 120 years ago but in some countries and for some applications it is a booming technology because it ticks more boxes today than it did in the past.
Lesser known food processing technologies like microwave and radio frequency, along with atmospheric pressure cold plasma are also worthwhile exploring and revisiting as times – and consumers’ tastes – change.
The work by Nicolas Appert in the 1790s and Louis Pasteur in the 1850s resulted in the revolution of food preservation – thermal processing. It took over from smoking and curing processes that had existed for millennia and became entrenched in the food manufacturing landscape as the go-to solution for product safety and shelf-life extension.
Canning, pasteurisation and UHT thermal-based techniques have been the default. As effective as they are when it comes to food safety and food spoilage, their disadvantages in product quality deterioration (e.g. nutrition and sensory attributes) mean alternatives need to be explored.
Enter non-thermal or ‘thermal gentle’ food processing technologies. Few are truly new technologies, with negative pressure cavitation extraction being a notable exception.
So if there are so many technologies available, why are so many almost dormant, and why are we relying on thermal processing so much?
One reason is consumer acceptance and economic considerations for research, industrial development and implementation. A lack of technological advances to overcome issues associated with technical or conceptual blocks in progress also plays a role.
But changing trends in foodborne and infectious disease mean some existing approaches of control are no longer as effective in combating new, emerging or maybe even re-emerging diseases.
Changes in foodborne disease trends can be driven by food trends, technological advancements or regulatory interventions based on corrective action following disease outbreaks and/or product recalls.
Factors that can contribute to changing trends in foodborne disease are:
- trends towards consumption of foods with minimal processing or that have inherently low microbial quality;
- a continued increase (or even sudden decrease as we’re seeing now) of the globalisation of food supply;
- development of new detection tools that enable greater sensitivity for detection of reportable pathogens;
- environmental/climate changes that alter (micro)ecosystems enabling new pathogens to flourish;
- pressure on agricultural land due to increasing urbanisation, bringing the natural environment into closer contact with humans, facilitating the transfer of new and emerging pathogens; and
- the increasingly rapid spread of antibiotic resistance in the non-clinical environment, which can result in a more severe disease and increase the prominence of a previously minor microorganism.
This is driving interest and update in technologies that offer great promise in this changing food manufacturing landscape.
HPP dates back to the 1890s and is possibly the most mature and well accepted of these technologies. Commercial operations are increasing year-on-year as prices drop and applications broaden. When this is combined with a solid body of scientific evidence for a broad range of microbe-inactivation scenarios and consumer acceptance, you have an all-round winner.
Other techniques developed many years ago, like ozonation as a form of cold plasma technology, are finding diverse niches, for example in domestic use and for elimination of residue agricultural chemicals like pesticides.
An approach, conceptually distinct from mechanical-based technologies is phage biocontrol, which has been commercially available for nearly 15 years. It was originally used by Georgia and Russia in a therapeutic context as an alternative to antibiotics from the 1930s. Phage biocontrol technology started as an extremely effective, safe and sustainable biological control method to reduce or even eliminate Listeria monocyotgenes contamination on food surfaces.
What we do know, is that with the rapidly changing foodborne and infectious disease landscape, science and technology have the tools to combat nearly any food safety or food spoilage assault.
