Emerging technologies for food powder decontamination

19 April 2021 | Danny Bayliss, New Technology Lead

Food powders are abundant in the food industry, which isn’t surprising considering their widespread uses in the market. Whether it’s spices, seasonings, ingredients in snacks or for use in product formulations, when a food is in a powdered form it can be much easier to handle and transport due to its high bulk density and typically long shelf-life. Yet food in this form can harbour pathogens if not treated properly, and some decontamination technologies may impact the product’s properties, hence the need to identify new ways to decontaminate powders.

Pasteurisation or sterilisation of food powders using established and emerging technologies can provide solutions to safeguard consumers and manufacturers.

Powders and food safety risk

Food powders have been historically considered a low food safety risk due to their low moisture (it was believed that the limited water reduced the likelihood of microbial growth). However, it’s now widely known that microorganisms in low aw products can survive for extended periods of time, especially Salmonella. As a result, outbreaks can occur in these products. For example, in 2014-2015 in Sweden, 174 cases of food poisoning were reported due to Salmonella enteritidis contamination of imported vegetable spice mixes.

Pasteurisation or sterilisation of food powders using established and emerging technologies can provide solutions to safeguard consumers and manufacturers. However, one of the key challenges in using decontamination technologies for food powders is minimising the adverse impact of processing on a product’s organoleptic properties, nutritional and also functional characteristics. This is where new technologies come in.

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Emerging technologies – what should be considered

A few of the technological powder processing challenges that manufacturers have to consider when selecting the most appropriate technology include ensuring powder flowability and the effects of particle size and packing density, homogeneity of bulk treatment, clumping or agglomeration of fine powders and risks of powder-dust explosion.

Powder-dust explosions are a great risk and can be caused by using temperatures above the minimum ignition threshold and by a build-up of static electricity or shaking and friction of metal parts that might generate sparks and ignite powder-dust clouds.

Identifying emerging technologies

As part of our project that investigates new technologies to help the food industry, our team at Campden BRI has identified some emerging technologies that hold potential as alternative methods of powder decontamination. Briefly, the emerging processes identified include infrared, radio frequency, microwave pasteurisation, irradiation, UV-C light and pulsed ultraviolet light. Most of these emerging technologies are either in laboratory or pilot scale level of development and require further research, improvement and optimisation to be commercially feasible.

Taking UV-C as an example, this technology is readily used in food production for the decontamination of product surfaces and packaging, however, applications for powder decontamination are still in early stages of research due to the need to fluidise powders during processing to ensure uniform exposure. Despite one trial achieving inactivation levels of 1.7 to 4.0 log for Lactobacillus plantarum, the difficulty with UV powder treatment systems is achieving the inactivation levels at a larger scale due to the shadowing effect and the risks of powder dust explosions. Therefore, this issue would need to be overcome before UV powder could effectively be used at scale in the food industry.

New technologies research

Each year we monitor and evaluate new technologies that our members see as holding the greatest value and potential to help the food industry. This article was adapted from part of a recent output of this project: a bulletin that includes case studies of the new tech, a technology newsfile and a patent review. In this most recent bulletin, we focused on new technologies for low water activity food powder decontamination. The bulletin is free and exclusive for members of Campden BRI.

We’re always looking for feedback on technologies to explore or review. Submit your suggestions to newtechnologies@campdenbri.co.uk so we can investigate technologies that interest you.

About Danny Bayliss

After finishing his PhD in cold plasma technology Danny joined Campden BRI where he has been in various new technology roles since 2012. Danny's main research interests have been in the field of emerging processing and preservation technologies for the food industry. He has knowledge in a range of emerging technologies including ohmic heating, power ultrasound, high-pressure processing, Revtech processing, pulsed light, and ultraviolet light processing with a particular interest in cold plasma. Danny manages the new technologies research team that works on confidential project work focusing on the feasibility of emerging technologies, technology validation/challenge testing, technology scouting, training, and consultancy on equipment process management. In addition to contract work, Danny has active roles in innovative research projects funded through various funding schemes such as Innovate UK, FSA, and European-funded agencies.

Danny sits on a BSI committee for UV C disinfection and is part of the Food and Beverage task force at the International UV association. He is an Industrial supervisor for a PhD focused on the development of cold plasma technology for continuous decontamination and also manages the Campden BRI funded research, projects which focus on new processing technologies.