What is the Difference Between pH and Titratable Acidity?

The difference between pH and titratable acidity lies in their measurement and what they represent. Here are the key differences:

• pH: It is a measure of the concentration of free hydrogen ions (protons) in a solution. The pH scale ranges from 0 to 14, with values below 7 indicating acidic conditions, and values above 7 indicating alkaline or basic conditions. The lower the pH value, the higher the acidity, and the higher the pH value, the lower the acidity.
• Titratable Acidity: It is a measure of the total amount of hydrogen ions (protons) in a solution, including both free and bound protons. Titratable acidity is typically expressed in grams per liter (g/L) and represents the total concentration of protons in a solution that can react with a strong base.

There is no direct or predictable relationship between pH and titratable acidity, and the same titratable acidity can be measured in different solutions with either low pH or high pH. The titratable acidity is always less than the total acidity because not all of the hydrogen ions expected from the acids are found during the determination.

In summary, pH represents the concentration of free hydrogen ions in a solution, while titratable acidity measures the total amount of hydrogen ions, including both free and bound protons. These two parameters are different ways of measuring acidity and cannot be converted or correlated to each other.

Comparative Table: pH vs Titratable Acidity

The difference between pH and titratable acidity lies in the units of measurement and the specific aspect of acidity they measure. Here is a comparison of the two:

In summary, pH measures the concentration of free protons in a solution, while titratable acidity measures the total concentration of free protons and undissociated acids in a solution. These measurements provide different insights into the acidity of food and beverages, with pH being more useful for process control purposes and titratable acidity providing information on organic acids and their impact on food properties.