A research project on microwave cooking of cereal products

CAPS (Cuisson Alternative des Produits Céréaliers Secs) is a research project funded by the Institut Carnot QUALIMENT, coordinated by the ONIRIS-GEPEA laboratory (UMR CNRS 6144) in collaboration with the CTCPA. The main objective of this project is to study microwaves as a new baking method for cookies, and thus propose a decarbonization solution for this sector. The project also aims toassess the impact of this cooking method on nutritional quality, by evaluating acrylamide content andglycemic index.

Following a small-scale exploratory phase in Nantes, tests were carried out at the CTCPA microwave pilot oven in Avignon last March on two types of cookie dough: a "laminated" dough and a "rotary" dough, with different levels of hydration. Around 5,000 dough pieces of each type were baked during the week-long trial, varying the power of the generators (8 independent generators), the speed of the conveyor (5 meters long) and the humidity in the tunnel. Temperature probes were used to monitor the temperature of the dough pieces throughout the baking process.

These trials validated the feasibility of microwave baking of cookies, and enabled us to refine calculations of energy savings under real-life conditions. For these tests, the final coloring was carried out in a conventional oven, but the aim of the project is to integrate infra-red technology to complement the use of microwaves. The results obtained during this week of tests are very encouraging, and sensory studies, carried out by ONIRIS, are underway to assess the sensory and nutritional impact of microwave cooking compared with conventional oven cooking.

Acrylamide: This compound forms naturally during high-temperature cooking of starch-rich foods and is classified as probably carcinogenic to humans according to the IARC classification. Since 2018, European regulation 2017/2158 has made it mandatory to integrate acrylamide risk into the HACCP approach, identifying food processing stages likely to lead to the formation of this compound and determining actions to reduce its presence. Food industry operators must implement mitigation measures to achieve reference levels. Mitigation measures are actions that have been proven to reduce acrylamide levels. These reference levels are not regulatory maximum levels, but performance indicators used to verify the effectiveness of the measures. Exceeding these reference levels does not lead to "non-compliance", but requires immediate reconsideration of mitigation measures.

The project also focuses on the reduction, or even elimination, of raising powders, in particular ammonium bicarbonate (precursor of acrylamide formation) and sodium bicarbonate (sodium reduction), by kneading under CO2 pressure.