"The mineral may be any one of calcium, magnesium, potassium, zinc, sodium, iron, and their various combinations.Powder mixes may also contain buffering agents such as citrate and phosphate buffers, and effervescent agents formed from carbonates, e.g. bicarbonates such as sodium or ammonium bicarbonate, and a solid acid, for example citric acid or an acid citrate salt.The soluble fibre can be prese" . . . .