Calcium benzoate Calcium benzoate Calcium benzoate refers to the calcium salt of benzoic acid. When used in the food industry as a preservative, its E number is E213 (INS number 213); it is approved for use as a food additive in the EU, USA and Australia and New Zealand. The formulas and structures of calcium carboxylate derivatives of calcium and related metals are complex. Generally the coordination number is eight and the carboxylates form Ca-O bonds. Another variable is the degree of hydration. It is preferentially used more than other benzoic acid salts or its esters in foods due to its better
Calcium metabolism This process is known as the sliding filament model of muscle contraction. The plasma "total calcium" concentration is in the range of 2.2-2.6 mmol/L (9-10.5 mg/dL), and the normal "ionized calcium" is 1.3-1.5 mmol/L (4.5-5.6 mg/dL). The amount of total calcium in the blood varies with the level of plasma albumin, the most abundant protein in plasma, and therefore the main carrier of protein-bound calcium in the blood. The biologic effect of calcium is, however, determined by the amount of "ionized calcium", rather than the total calcium. It is therefore the plasma ionized calcium level which is tightly regulated to