Lemon juice is a ubiquitous household ingredient prized for its bright flavor, fragrant aroma, and remarkable chemical profile. From hair care and baking to cleaning and first‑aid, its versatility stems from a combination of strong acidity, high vitamin C content, and natural antimicrobial activity.
Lemon juice registers a pH of approximately 2, placing it just below stomach acid on the scale. This high concentration of hydrogen ions gives it a sharp, sour taste and the ability to corrode metals. In cleaning formulations, the acidity breaks down mineral deposits in hard water, allowing detergents to work more efficiently. The corrosive action also makes lemon juice a natural scale remover and brightener for household surfaces.
On average, lemons contain roughly 30 mg of vitamin C per 100 g—about twice the amount found in oranges. First noted by physicians in the 17th century, this high vitamin C level proved effective in preventing scurvy when consumed daily. However, the antioxidant benefits diminish when the juice is exposed to air for extended periods, underscoring the importance of fresh preparation.
Research indicates that lemon juice can inhibit the growth of Aspergillus mold and has been employed to disinfect drinking water and neutralize the rabies virus. These effects are largely attributable to its citric acid content, which disrupts bacterial cell membranes and hampers pathogen replication.
