Comparison of trace element solubility from food items treated separately and in combination.

Solubility of trace elements from various foods (beef, soya, crab, wholemeal and white bread) is assessed with various extractants, at different pH's and after enzyme treatment. Simple extractants do not solubilise trace elements to the same degree as when they are released after digestive enzyme action. Enzymic action can change the nature of the soluble species as well as their amount. Trace element solubility from one food can be affected markedly by the presence of another food, e.g. soya enhances the solubility of iron from beef but suppresses zinc solubility. Trace elements that are bound to the insoluble residue after enzymolysis are soluble in saline solution on subsequent extraction in only isolated instances.