The acidic component in lemons does contain some natural lightening properties.
When wool is treated with a metallic salt it hydrolyses the salt into an acidic and basic component.
The basic component is absorbed at -COOH group and the acidic component is removed during washing.
Vinegar, being acidic, is a better solvent for obtaining alkaloids but a poorer solvent for acidic components.
It is critically important to exclude sulphur and any acidic components from these mixtures.
This comination of flavor often results in complex flavors with sweet, salty and acidic components.
Amine gas treating, an industrial scale process which removes acidic gaseous components, is often used to remove hydrogen sulfide from natural gas.
But using buttermilk, instead, for the necessary acidic component (which ensures that the meat is tender), makes this chicken less Mediterranean and more down home.
Alum is used as the acidic component of some commercial baking powders.
In contrast, basic dyes are used to stain cell nuclei and some other acidic components of tissues.