Optimizing fat in snack foods to reduce health risks

This innovation story comes to us from Ryerson University.

Toronto – Eliminating or reducing unhealthy fats in food comes down to chemistry. Consumers are more aware than ever of what they eat and how it affects their health, leading to the rise of low-fat products.

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PhD Student Ryan West uses a tempering kettle to control temperature and cooling rates of fat and sugar blends at Dr. Dérick Rousseau’s Food Research Lab. Source: Ryerson University

Dr. Dérick Rousseau, Professor of Chemistry and Biology at Ryerson University, and his PhD student Ryan West work with various food companies to help them reduce such fats in their product lines.

Their research on the chemical composition of fats is yielding new insights into the development and reformulation of everyday foods found on the shelves of our grocery stores.

Partially hydrogenated vegetable oils are processed to make baked goods with the same semi-solid texture and consistency as traditional fats used in the past, such as lard.

However, these oils are also dietary sources of “trans fats,” which have been linked to heart disease and inflammation.

Health Canada and the United States Food and Drug Administration are currently reviewing the “generally recognized as safe” (GRAS) status of partially hydrogenated vegetable oils, with the goal to eliminate trans fats from all food products.

Researchers at the Ryerson Food Research Lab, directed by Dr. Rousseau, are exploring new ways to reduce partially hydrogenated vegetable oils.

Product reformulation, however, can be challenging, as consumers have certain expectations from a product, such as its taste, texture, and melting properties.

“At the Lab, we are examining the fundamentals of processed foods, such as the physical properties of different fats and how they interact with other ingredients. The success of product development and reformulation depends on understanding how factors at the microscopic level influence those at the macroscopic or product level,” explains Dr. Rousseau.

For instance, with icings or creams, consumers typically want a product that is smooth in texture and melts evenly in the mouth.

The fat in icings or creams can be manipulated via processing to reach an optimal sensory experience at consumption.

Using a tempering kettle, the research team controls the heating and cooling temperatures of different fats over different time periods to examine their impact on fat crystallization.

Fat solidifies along a molecular pathway to eventually crystallize and reach a lower stable state.

Along the way, there is a cut-off point when the product may no longer have the desired texture because the fat crystals grow too large in size.

As fat crystallizes, its molecules group into different three-dimensional arrangements, known as polymorphs that can dictate fat crystal size and shape, and ultimately product texture. Thus, improper tempering can lead to products with pasty or grainy textures.

The fat crystallization pathway can also be affected when common ingredients such as dairy solids, sugar, or emulsifiers that keep ingredients blended are added.

The research team is exploring different fat blends and examining how they crystallize under different processing conditions.

The information gained from this research will help to establish and optimize strategies in industry to improve the processing of commercial products that undergo fat crystallization.