If you bite into a lemon, an acid develops that tightens everything but particularly affects the sides of the tongue and strongly stimulates salivation. This reaction is due to the high citric acid content. However, there is more behind the acidity. The taste of a lemon is not only intensely sour but also sharp and tangy. The peel and the white interior also contribute a bright, citrus-like aroma and a hint of bitterness.