Acids in Everyday Substances

Acids are chemical compounds that taste sour and release positive hydrogen ions (H⁺) in aqueous solution.  

Examples of Natural Acids  

- Ellagic Acid: Found in strawberries, walnuts, grapes, pecan nuts, cranberries, and raspberries. Known for its neuroprotective properties linked to reduced risk of depression and anxiety, with mood-stabilising effects similar to pharmaceutical antidepressants.  

- Malic Acid: Present in apples.  

- Formic Acid: Found in red ants, also present in broccoli, cauliflower, and avocados.  

- Ascorbic Acid (Vitamin C): Found in citrus fruits such as oranges, lemons, and limes.  

- Acetic Acid: Found in vinegar.  

- Oxalic Acid: Present in tomatoes.  

- Lactic Acid: Found in curd.  

- Citric Acid: Present in lime, orange, lemon, and pomegranate.  

- Tartaric Acid: Found in tamarind and grapes.  

Key Insight  

Acids are not only laboratory chemicals but also naturally present in the foods we consume daily. Their presence explains the sour taste of many fruits and fermented products, while some (like ellagic acid and vitamin C) also provide health benefits.