Sitraatit

Sitraatit is the Finnish term for citrate salts, the salts and esters of citric acid (2-hydroxypropane-1,2,3-tricarboxylic acid). In water, citrate exists mainly as tri- or di-anions depending on pH. Common sitraatit include trisodium citrate, potassium citrate, and calcium citrate; commercially they are sold as powders or solutions for food, medical, or laboratory use.

Synthesis and occurrence: Citric acid is industrially produced by fermentation, often using the mold Aspergillus niger. Neutralization with bases yields citrate salts such as trisodium citrate, which are then purified and formulated for various applications. Citrate salts occur naturally in citrus fruits as part of the citrate cycle of metabolism.

Uses: In the food industry, sitraatit act as acidity regulators, buffering agents, and sequestrants. Sodium citrate, for example, is used under the code E331. In medicine, sodium citrate serves as an anticoagulant in blood collection tubes and as a buffering agent; calcium and other citrate salts are used as dietary supplements or in medical formulations. In biochemical and clinical laboratories, trisodium citrate functions as a buffer and anticoagulant, and is used in various diagnostic tests and preparation steps. Citrate buffers are also used in chromatography and other analytical procedures.

Safety and regulation: Citrates are generally recognized as safe for use in foods. Side effects are uncommon with normal dietary or veterinary use, but excessive intake can cause digestive upset or electrolyte imbalances, including hypocalcemia, and may affect acid–base balance, particularly in individuals with kidney impairment or other medical conditions. Regulatory status and approved uses vary by country and application.