Initial research results are indicating that canned vegetables could potentially be processed safely at lower temperatures – a change that would improve their taste and nutritional qualities.
Currently, food safety regulations governing canning in Canada recognize two thermal processes for canned foods – high acid (pH lower than 4.5) products that need only mild heat (resulting in potentially unacceptable acidic flavour) and low acid products (pH greater than 4.5) that need to be heated to a high temperature in order to ensure safety. Unfortunately, those high temperatures also affect the quality and nutritional value of canned foods.
Dr. Tony Savard is leading a project at the Agriculture and Agri-Food Canada (AAFC) Food Research Development Centre in St-Hyacinthe that is hoping to gain a better understanding of how both Clostridium botulinum and Clostridium sporogenes – a pathogen and its surrogate that can cause food-borne illness – respond to a combination of treatments instead of just a high heat process and is documenting the real thermo-resistance of those strains in a non-regulated zone of pH.
“The current thermo-resistance data and calculations for high thermal processing were done more 50 years ago,” explains Dr. Savard. “We want to use what is called “hurdle technology” – an intermediate pH level combined with reduced thermal processing that will ensure the same food safety while boosting quality and stability.”
The general objective, he adds, is to validate how well the pathogens react to heat in acidic conditions both in the lab and at a pilot plant scale. The impact on C. botulinum of salt in canned vegetable liquid as well as a reduction in those sodium levels will also be evaluated.
“Looking at sodium reduction is helping us prepare for potential future developments,” he says, adding that it is important to know whether reduced salt levels that may be introduced down the road could potentially cause resurgence in pathogens like Clostridium.
Experiments have been conducted successfully over the past year involving green beans but raised a few questions that are being answered in this project. Challenge tests will also be performed on carrots to ensure the results are applicable beyond just green beans.
“We’ve found no significant impact on the activation of Clostridium spores either in our buffer or in our green bean slurry, either immediately after processing or after four months, but the way the spores are produced has a significant impact on their resistance to heat,” Dr. Savard says.
Dr. Savard says AAFC has been consulting with both Health Canada and the Canadian Food Inspection Agency on this work since its inception to ensure both agencies are aware of the potential future impact it might have on regulations governing food canning.
Why is this innovation important?
Food safety: The “hurdle technology” combining acidity and temperature levels meets food safety standards for human consumption.
Policy: Regulations governing thermo-resistance of foodborne pathogens and calculations for high thermal processing were put in place more than 50 years ago, even though technologies have advanced during this time.
Markets: This innovation’s success could help Bonduelle achieve regulatory approval to use reduced thermal treatments to can vegetables – the resulting tastier, more nutritious foods could open new markets for the company.
What does this innovation mean to Canada’s food processing industry?
A successful project will mean that companies can reduce their levels of thermal processing during canning, leading to tastier, and more nutritious canned vegetables. Overall, this outcome will help the canning sector to increase its worldwide competitiveness.
About Bonduelle Group
The French family-run Bonduelle Group is one of the largest fruit and vegetable processors in the world with markets in over 100 countries and more than 50 processing facilities worldwide. Bonduelle’s Canadian presence includes offices in Quebec and Ontario, and four processing plants in Quebec, three in Ontario, and one in Alberta, where they make product for national and private label brands such as President’s Choice, Selection, Irresistible, Green Giant, and Arctic Garden. foodservice.bonduelleamericas.com/en/
About the project team
Dr. Tony Savard is a research scientist in food microbiology with Agriculture and Agri-Food Canada’s Food Research Development Centre in St-Hyacinthe, where he has worked since 1999. He holds a BSc and a PhD in Microbiology and an MSc in Neurophysiology, all from Université de Sherbrooke.