Oxalic acid commonly occurs in many plants, combines with Ca, Fe, Na, Mg or K to form less soluble salts known as oxalates. High levels in diets lead to irritation of the digestive system, and particularly of the stomach and kidneys. It is also known to contribute to the formation of kidney stones. The urinary level of oxalic acid has long been recognized as an important indicator for the diagnosis of renal stone formation. Read full article to get more information and facts about oxalic acid.
Oxalic acid can be derived either from malt or from the fermentation process. Through the use of additives, this problem can be solved. In the mashing process, with more calcium ion added, the oxalate quickly combines with calcium ions and forms a precipitate, and then this precipitate should be removed as soon as possible. On one hand, it reduces the chances of calcium oxalate being brought to the bottled beer.
On the other, it reduces the chances of oxalic acid from being brought into the beer body, which could cause too much loss of calcium from the body. In high-grade beer, the oxalate content is usually controlled at 10–15 mg/L. However, too much calcium is also not allowed, in case of the great influence of calcium on the condensation of yeast.
Oxalic acid is a metabolite of the TCA cycle in the cells. The determination of oxalate in urine and blood is of great interest, as it is required in the diagnosis and medical management of idiopathic urolithiasis and various other intestinal diseases. Many analytical methods have been reported for the determination of oxalate, which are bulky, time-consuming, less sensitive, and require pretreatment of the sample. Therefore, the demand for a simple, sensitive, accurate, and rapid method has been raised.