Large amounts of the food we produce do not end up in our stomachs, but in landfills, sewers, or elsewhere. According to the UN, in 2022 this was the fate of 1.05 billion tonnes of food, which ended up as food waste— corresponding to approx. 132 kg per capita in the world.
Milk is one of the foods where a significant percentage goes to waste. A study from the University of Edinburgh shows that one in six litres of milk produced around the world goes to waste. The root cause of this waste can be found early on in the production process. Each day, every dairy in the world pours an average of around 10,000 litres of milk down the drain.
This waste is something that happens every day. Not because the milk has gone off—on the contrary, it is completely fresh. It happens when milk is used to flush the pipes that transport the milk through the production plant and into the cartons. In this way, the dairies ensure that any excess cleaning fluid used to clean the pipes between production runs is completely flushed out with the milk and into the drains before a new production can start.
In the Nexus consortium, researchers from DTU and three tech companies have joined forces to rethink how milk production—and potentially other food production—is controlled. Together, they have developed an ultra-compact optical spectrometer (see fact box) in the form of a microchip that makes it possible to see the amount of liquid, fat, and proteins in the pipes. It thus makes it possible to identify whether milk residues from a previous production run or cleaning products are present.
