More energy-efficient bread baking with synchrotron microtomography 

Increased energy efficiency during bread baking can save time and energy, lower greenhouse gas emissions, and save money. Scientists from Finax and researchers from RISE, the Faculty of Engineering at Lund University, and MAX IV used time-resolved synchrotron micro TomographyA non-destructive technique used for constructing three-dimensional images from two-dimensional projections to characterise the internal structures of materials.More info to explore ways to make bread baking more energy efficient. 

Bread is a worldwide staple food, and baking industries across the globe supply food to millions of consumers every day. The oven is the largest energy consumer in industrial bakeries, leading more companies to explore new ways of baking bread, such as microwave-convective baking. 

Microwave-convective baking offers an energy-efficient way to bake bread in a shorter processing time. It could potentially help the industry overcome the challenge of reducing baking times while at the same time maintaining desired bread volume and quality properties.

The technology also makes it possible to achieve good bread quality in terms of texture, how it feels in the mouth and its porosity. Yet, knowledge gaps still exist.

Learning about bread’s elasticity and bubble formation using synchrotron X-rays 

Will the air bubbles have time to form in the dough with microwave baking? This process is vital to creating a loft and desirable structure. How will the short processing time affect water distribution between starch granules and gluten? More knowledge of water distribution is crucial since it will influence the bread’s elasticity and bubble formation. 

Synchrotron X-ray micro TomographyA non-destructive technique used for constructing three-dimensional images from two-dimensional projections to characterise the internal structures of materials.More info (SRμCT) can answer some of these questions since the technique, with its high temporal and spatial resolution, makes it possible to perform an in-situ experiment to study the volume expansion that takes place during bread baking. 

A purpose-built oven enabling in-situ experiments 

For the experiment, researchers from Finax, RISE, the Faculty of Engineering at Lund University, and MAX IV built a tailor-made microwave-convective oven to perform SRμCT experiments during baking at the TOMCAT beamline of the Swiss Light Source at PSI in Switzerland.

Ahead of the experiment, a pre-study was conducted to identify relevant processes and formulation conditions before the three-day beamtime experiment began.  

Loaves of bread made from three different flour types with varying protein content were baked in the oven using microwave, microwave-convective and convective heating. All the samples were prepared in advance, frozen, and brought to the facility. 

Visualising with the TOMCAT beamline 

The results showed that it is possible to determine a timeline of the bubble structure in the dough before, during, and after baking using the TOMCAT beamline. The data captured during the experiment provided the scientists and researchers with a visual representation in the form of 3D structure images of how the bubbles formed, their size, and the bread’s porosity and shape. 

The experiment also showed that the baking method and flour type significantly influence the bubble growth kinetics and the final bread structure. 

Sustainable and better-tasting bread with synchrotron-based research

The collaboration produced valuable results about how bread can be baked with more sustainable microwave-convective technologies, specifically in terms of the methods and flours most suited to shorter baking processes.  

The results are also significant since they provide a better understanding of how water is transported in bread and new knowledge that can support the development of processes to make bread fresher and, at the same time, extend its shelf life.