Last July, while touring a jelly bean factory, I came upon a startling sight. Over a conveyor belt, a large robot spider danced over packets of sweets, plucking each one up with human speed and precision and placing it in a carton. The packets were piled willy-nilly, but the machine and its colleagues – two others were also manning the line – seemed to know where each one was and worked together to collect them all in seconds. It was riveting, and not a little eerie.

It turns out these robots are based on a design by Swiss robotics professor Reymond Clavel of the Ecole Polytechnique Federal de Lausanne, called a delta robot. They are incredibly quick and can do jobs in food packaging that only humans used to be able to do, like sorting or stacking randomly arranged objects, without the repetitive stress injuries such tasks give people.

Automation in the food industry has moved far beyond the simple labelling machines and conveyor belts you may be familiar with. Now intelligent robotic arms perform dazzling movements and expert feats of coordination, getting everything from frozen fish chunks to cookies swiftly into their packaging. It's not a side of processed foods you see that much, but it is everywhere.

To find out more about how they work, I spoke to Klas Bengtsson, a product manager at ABB, a Swiss company which makes food-grabbing delta robots.

Here are the robots at work at a Honeytop Specialty Foods factory, with a soundtrack that sounds a bit “Mission: Impossible”: