IT is regarded as one of Scotland's national dishes and the cornerstone of hearty breakfasts going back centuries.

But now scientists say that the secrets of making porridge may in fact have first been cracked by ancient Europeans living more than 30,000 years ago.

Archaeologists have uncovered a stone grinding tool in southern Italy which shows signs it was used to make flour that was boiled into gruel or baked into bread.

The discovery, which predates the dawn of farming, suggests that stone age man's first cultivated meal may have been a bowl of porridge made from grains growing wild and is the earliest known instance of human consumption of oats.

The find was made by a team led by Marta Mariotti Lippi at the University of Florence in Italy who made analysed starch grains found on the artefact.

They found evidence that the stone's creators also heated the grains before grinding them, perhaps to dry them out in the colder climate of the time and make the grain easier to grind and longer-lasting.

This multi-stage process would have been time consuming, but beneficial, while turning it into flour would have been a good way to transport it, which was important for Palaeolithic nomads.

Evidence of porridge consumption in Scotland dates back to 4,000 BC, when oats and other grains began to be cultivated by the first farmers.

Mariotti Lippi’s team hopes to continue studying ancient grinding stones to find out more about the stone age plant diet.

The stone was found in the Grotta Paglicci, Apulia, which was home to stone age hunter gatherers between 34,000 and 32,000 years ago and contains mural paintings, depicting horses and handprints. Images of goats, cows, a serpent, a nest with eggs, and a hunting scene have also been found engraved on bone.

Archaeologist Matt Pope, of University College London, said that the find shed light on the diet of early humans and the spread of food cultivation.

He said: “There is a relationship there to be explored between diet, experimentation with processing plant food and cultural sophistication.

“We’ve had evidence of the processing of roots and cattails, but here we’ve got a grain, and a grain that we’re very familiar with.

“If we were to look more systematically for ground stone technology we would find this is a more widespread phenomenon.”