PURPOSE: A powder of perlite, pitch stone or obsidian or the supernatant obtained when the powder is dipped in water is added to a food product in its production to improve the quality of the product.

CONSTITUTION: A supernatant after a powder or granules containing minerals such as of perlite, pitch stone or obsidian and several metallic ions is dipped in water or the powder itself are used at a ratio of 50W100g/l liter of water to prepare a dough and bread is made from the dough by a usual method. This process is described to be effective in the production of sponge cake, doughnuts and biscuits.