Is Lemon Acidic or Alkaline?
Lemons are highly acidic due to their high citric acid content, with a pH well below 7. 1
Chemical Composition of Lemons
Lemons contain significant amounts of citric acid, which gives them their characteristic sour taste. Research has quantified the citric acid content in lemon juice at approximately 1.44 g/oz (about 48 g/L), making it one of the richest natural sources of citric acid 1. This high concentration of citric acid results in a low pH, classifying lemons as acidic substances.
The acidic nature of lemons is further confirmed by chemical analysis showing:
- Titratable acidity of approximately 52.4 g/L in direct lemon juice 2
- Citric acid as the predominant organic acid in lemons 3
- During fruit development, citric acid becomes the major organic acid in acidic citrus varieties like lemons 3
pH and Acidic Properties
The acidic properties of lemons are well-established in scientific literature:
- Lemon juice has a pH well below 7 (neutral), placing it firmly in the acidic range
- The high concentration of citric acid contributes to its strong acidic properties
- The acidic nature of lemon juice is so pronounced that it can be used to inhibit certain enzymatic activities 4
Practical Applications of Lemon's Acidity
The acidic nature of lemons has several practical applications in health and cooking:
Reduction of glycemic response: Lemon juice can lower blood glucose concentration peaks by approximately 30% when consumed with starchy foods like bread, likely due to its acidity inhibiting salivary α-amylase 4
Culinary uses: The acidic pH of lemon juice makes it useful in cooking for:
- Marinades (the acid helps tenderize proteins)
- Preventing enzymatic browning in fruits
- Preserving food due to its low pH environment that inhibits bacterial growth
Medical applications: Lemon's acidity can be beneficial in certain contexts:
Common Misconceptions
Despite their acidic nature, there is a common misconception that lemons have an alkalizing effect on the body after metabolism. However, this claim lacks scientific support in the medical literature. The evidence clearly demonstrates that lemons are acidic in their natural state due to their high citric acid content.
Conclusion
From a chemical perspective, lemons are definitively acidic substances with a pH significantly below 7, primarily due to their high citric acid content. This acidity gives lemons their characteristic sour taste and makes them valuable for various culinary and potential health applications.