Phosphoric acid in coffee

Axit phosphoric

In coffee there are more than thirty organic acids perhaps the most common including citric, malic, acetic, quinic, etc. But there is another branch of acids, namely inorganic acids, which is recognized in particular, among these acids phosphoric acid has a particularly important role.

In coffee, phosphoric acid makes up less than 1% of coffee's dry matter and is formed from the hydrolysis of phytic acid from the soil. However, unlike some other acids - phosphoric is the strongest and can easily be 100 times stronger than others. Therefore, many researchers believe that phosphoric acid plays an important role in sensing the acidity of coffee.

While the argument is well supported, there is some debate about how much phosphoric acid actually contributes to sourness. Those say that because phosphoric acid is strong, it makes a much greater contribution in contributing hydrogens, affecting the final sourness.

While those elsewhere claim that phosphoric acid, although potent, is neutralized by an equal amount of potassium in pure coffee. A 1999 study conducted by J. Rivera of the Coffee Quality Institute found an inverse relationship between acid concentration and phosphate concentration. Further studies are needed to further establish a clear role between organic/inorganic acids and the quality of their role.

Axit Phytic

Interestingly, higher phosphate levels have been noted in both dry processed robusta and arabica, but their role in perceived acidity remains a mystery. Although wet-processed arabicas tend to contain the lowest concentrations of phosphate, this is partly seen due to mineral extraction during fermentation.

It has also been noted that residual phosphoric acid persists during roasting with an estimated figure listed in the Table below.

Caption

The increase in phosphoric acid at higher roasting levels is not yet understood and may be due to artifacts created during the analysis – as further research is needed.