Types of Acid

• Citrus fruits contain both citric acid and ascorbic acid. Citric acid is considered a good detoxifier and has a sour taste. Citric acid can also be used as an eco-friendly cleaning solution. Ascorbic acid is also known as Vitamin C.
  
  

Measuring Acidity

• Image by Flickr.com, courtesy of Paul Hart
  
  Acid content is measured by pH. The "H" in pH refers to hydrogen found in a substance. The meaning of the "p" found in pH is under some debate, meaning possibly "potential", "power" or "negative logarithm". The pH is measured on a scale from 0 to 14, with "0" being the most acidic, "7" being neutral and "14" being the most alkaline, or acidic.
  
  

Most Acidic Citrus Fruits

• The most acidic of the citrus fruits are: Tangerine: pH 3.90; grapefruit, pH 3.38; lime: pH 2.40; and lemon: pH 2.30.
  
  

Least Acidic Citrus Fruits

• The least acidic of the citrus fruits are mandarin, pH 11.50; orange, pH 4.35; and kumquat: pH 3.95.
  
  

Considerations

• The acid levels of fruits decrease as the fruit ages. The acid levels may also vary depending on the variety of the fruit and the growing conditions.