Enormous energy savings potential in the production of baked goods is found above all in the core of the entire process, namely the baking itself. Energy analyses demonstrate that over half of the energy used goes into the baking ovens alone, and only one third of this energy actually goes into heating the baked product: the rest simply heats the surrounding area.

The analysis data show unmistakably that baking energy efficiency is a key factor for more environmentally-friendly production and for sinking production costs. In addition to high energy costs, there are also expenditures related to CO2 emissions. The duration of the baking time also often pushes com-panies to the limits of their time resources. So with innovations in baking oven technology in demand, business figures and scientists came up with the idea of applying a combustion principle developed at the Friedrich-Alexander University Erlangen-Nürnberg/Germany in food product processing for the first time.

The principle used with volumetric ceramic burners (VCB), also known as porous burners, has already proven itself in other industrial fields of application to be particularly energy efficient, low in emissions and robust. The reaction between the fuel and oxygen takes place in hollow spaces in the ceramic porous container without any open flame. The benefits of this method include very fast heat transfer, easy adjustability, low pollutant values and stable combustion, even with fluctuating fuel properties.

At the centre of the research project, a commercial electric deck oven was retrofitted with twelve volumetric ceramic burners. An unconverted oven of the same model served as the reference in the comprehensive baking tests. The reference product used was an 800 g loaf of wheat bread.

The aim of the experiments was to compare the converted VCB oven with the unconverted oven of the same model and to verify the test oven’s suitability for the production of baked goods. Following the construction and operation of the VCB oven, extensive baking tests were conducted and the quality of the final product was determined on the basis of various criteria such as weight, volume, crust colour, hardness, pore distribution of the crumb and elasticity. On this basis, the operational parameters of the VCB oven were then compared with the reference oven.

The testing demonstrated that the VCB oven achieved a temperature distribution comparable to that of the commercial electric deck oven. Regarding the quality criteria, there were no significant deviations in the baked bread loaves. The products were qualitatively absolutely equal, but the VCB oven demonstrated decisive advantages: the average baking time of the reference bread loaf in the VCB oven was able to be reduced by up to 20 %. The energy efficiency of the VCB-based baking oven is up to 45 % higher in comparison with the conventional gasoperated baking oven. Since the VCB oven is powered by natural gas or propane gas instead of electricity, the resulting energy expense savings range from 300 to 400 %.

The VCB oven excels with a continuous transfer of energy and far more flexible control that makes it possible to bake a variety of different products in the same oven at the same time. This innovative technology is also very well suited for other fields of application, including, for instance, the manufacture of thinly layered premium baked products such as biscuits.