A research project in which Ugo Javourez, a research student at the National Institute of Applied Sciences in Toulouse, has been participating for two years, proposes transforming waste into food.
In your research project, you are interested in the transformation of waste into food. What waste did you use?
We only used organic waste, which is not made of plastic or metal. There are things that could already be eaten but are little or not eaten at all, such as slaughterhouse waste such as guts and skins, or food residues. Then we looked at products a priori quite far from an edible food. There is wood waste such as sawdust, green waste such as branches, tons of grass, manure or sewage waste.
How can they be made into food?
Overall, there are four main families of methods. Food proteins, green waste, feathers, hair or sludge can be extracted. Wood waste allows us to produce and refine sugar. Animals, and especially insects, can help us convert waste into edible products. There is also fermentation: we will use microalgae for the concentrated nutrients found in wastewater, or bacteria to convert gases into proteins. Finally, some waste is already edible and our challenge will be to improve its taste and appearance. All these techniques are not plausible and acceptable, so we pushed our analysis on the techniques that limit health risks and that are based on our inevitable waste.
What can it be suitable for on the plate?
The current coherent strategies to manufacture analogs to products that we know well, alternatives to meat for example, or by including them in processed products. There are insect meal snacks. It avoids what is called food neophobia. If for the moment, the use of waste as food is mainly used in animal feed, their deployment on the shelves of our stores requires careful study of the cultural and social aspects.
What impact do these techniques have on the environment?
Studies show that producing food from waste reduces the pressure on the Earth. We limit deforestation, we generate profits on water, nitrogen, phosphorus which are used in agricultural crops. It should be noted that food today generates 30% of greenhouse gas emissions on a planetary scale.
Your project is part of a larger project on an entire economy based on the reuse of waste. What other ways are there to use the waste?
We call it the bioeconomy. Other people on my team study the transformation of waste into energy, fertilizers, materials, or even molecules. This raises the question of the services that we want to prioritize, because waste is also a limited resource. To arbitrate between all the possible valuations, and try to guide political choices, to anticipate the environmental impacts of each of these recyclings, and to propose a roadmap for the transition to a virtuous bioeconomy.