The King has visited the biggest Corn Flakes factory in the world, where he joked that he was a year late for the 100th anniversary of Kellogg’s in the UK.

Charles was at the Manchester site of Kellogg’s – the largest cereal factory in Europe – which produces breakfast favourites such as Corn Flakes, Frosties, Rice Krispies, Crunchy Nut and Coco Pops.

Kellogg’s celebrated a century in the UK last year, with Corn Flakes and All-Bran first introduced to the British public in 1922.

Charles, who unveiled a plaque marking his visit and celebrating 100 years of “bringing breakfast to Britain”, sparked laughter when he said: “Sorry I’m a year late.”

During his visit to the plant, which has just under 400 workers, Charles toured the culinary centre – a new research and development hub – where he viewed cooking demonstrations and saw the various cereals on offer.

He heard about efforts to reduce salt and sugar content, and enquired about the popularity of Coco Pops as he stood in front of a strawberry and white chocolate version of the cereal.

At one point as he chatted to workers, Charles could be heard commenting that he thinks molasses is “very special”.

The King donned a white coat for a walk around the factory floor, where he stopped and chatted to staff.

Kellogg’s has been a holder of the Royal Warrant since the reign of King George VI and cereal from the business was historically delivered to Buckingham Palace in a small van called Genevieve.

Charles also met a group of interns and engineering apprentices during his visit which lasted approximately an hour.

Speaking after the King departed, Chris Silcock, Kellogg’s managing director for UK and Ireland, said it was “fantastic” that Charles made a visit.

“It doesn’t get any better than that for us,” he said.

Mr Silcock said he found Charles “so warm and engaging”, adding that he was delighted to see the King’s “focus on people”, meeting apprentices and workers.

Earlier on Friday, Charles visited GCHQ’s North West hub.