The slightly tangy, sour taste of a ripe tomato is due to naturally occurring organic acids within it. In Chemistry, identifying which acid is present in common food items is a standard exam question.
The red color of tomatoes comes from a powerful antioxidant called Lycopene — not the acid content. Lycopene is actually protective against certain cancers and heart disease.
Tomatoes contain Oxalic Acid (C₂H₂O₄) as their primary characteristic acid.
However, tomatoes also contain significant amounts of:
The exact acid composition changes as the tomato ripens — unripe tomatoes are more acidic.
| Food | Natural Acid |
|---|---|
| Tomato | Oxalic acid / Citric acid |
| Lemon/Orange | Citric acid |
| Vinegar | Acetic acid |
| Milk (sour) | Lactic acid |
| Apple | Malic acid |
| Tamarind | Tartaric acid |
Botanically, a tomato is a **fruit** because it develops from the flower of the plant and contains seeds. However, in cooking and law (a famous 1893 US Supreme Court case!), it is classified as a vegetable.
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