Pyrofosfaatti

Pyrofosfaatti, or pyrophosphate, is a term used for salts and esters derived from pyrophosphoric acid. The core structural unit consists of two phosphate groups linked by an anhydride bond, giving commonly the pyrophosphate anion P2O7^4− in many inorganic salts. Pyrophosphoric acid (H4P2O7) forms when two phosphoric acid units condense with the loss of a water molecule. Pyrophosphates occur widely as inorganic salts such as disodium pyrophosphate Na2H2P2O7 and tetrasodium pyrophosphate Na4P2O7, and as organic esters used in biochemical and industrial contexts.

In chemistry and biochemistry, pyrophosphates play roles as buffering agents, sequestering agents, and stabilizers. In food technology, pyrophosphates are used as leavening agents, moisture retainers, and emulsifiers, and are listed in many jurisdictions as food additive E450. They help control acidity, maintain texture, and prevent metal-catalyzed spoilage. In detergents and processed foods, they act as water-softening agents and stabilizers.

Biochemically important is inorganic pyrophosphate (PPi), which is produced in cells during reactions such as ATP hydrolysis to AMP and PPi. PPi is often rapidly hydrolyzed by pyrophosphatases to two inorganic phosphate (Pi) molecules, a reaction that helps drive biosynthetic processes and nucleic acid metabolism forward.

Production and handling of pyrophosphates occur at industrial scales, typically involving dehydration and condensation reactions of phosphate derivatives. Regulatory status varies by form and jurisdiction, but many pyrophosphate salts are approved as food additives or industrial ingredients within specified limits. Safety considerations include potential irritation at high concentrations and the need to monitor phosphate intake in sensitive individuals.