Lucia,

Here is an explanation I got from the living-food.com bulletin board
posted
by matt aka rawislaw (I don't think he'd mind if I shared it):

there is a very good book on acid akaline but i cant seem to find it
at this
moment, so i cant tell you the exact name.

basically, alkaline foods are foods that are predominant in alkanline
minerals...calcium, magnesium, sodium, potassium, and iron. the
chemical
composition of these minerals make them alkaline. an alkaline molecule
is
any molecule that combines with protons, or proton receptors. here is
a good
defination of alkaline: alkalies are a class of chemical compounds,
also
called bases, wich have the property of forming the ion OH- in a
solution.

acid foods contain phosphorus, sulfur, chlorine, and iodine. (for a
food to
be acidic these must be prodominent in the food. an acid molecule is
any
molecule that gives protons to another substance (h+ ions), or proton
donors. here is the acid defination: acids are chemical compouds
containing
the element hydrogen, and having the ability to supply positively
charged
hydrogen ions to a chemical reaction.

ok....try this one out...a normal hydrogen atom has a proton circled
by an
electron. if the hydrogen atom loses that electron then only the
proton is
left. this is called hydrogen ion (H+). since it is not a normal state
for
the hydrogen atom it is chemically unstable and is an acid. it is
looking to
give up the proton. an alkaline has an extra electron to balance out
the
acid

citris is acicidic but the acids are organic and our body can get rid
of
these by respiration. here is an example. when an organic acid is
oxidized
it becomes carbon and water, or carbonic acid (H2CO3) .(carbonic acid
is
formed from combining carbon and water). then with respiration our
bodies
expell the CO2 and H2O is left over (water). and the alkaline minerals
are
left over to deal with inorganic acids in the body. here is what seems
strange to most people..."acid" foods (acid fruits) reduce body acids
b/c
of the alkaline minerals left over.

now with the other foods (Acid foods) the acids are inorganic, which
can
not be broken down into water and carbon dioxide. these need to have
the
alkaline substances to combine with them to make them safe to exit
through
the kidneys. (or where ever else they might go)

now protein is very acid. most of them in food combine with sulfur and
some with phosphorus. when the protein is metabolized they become
sulfuric
and phosphuric acid..and must be neutralized by those alkaline
elements (Ca,
Na, K, Mg, and Fe).

grains are also very acidic (except millet and maybe another one). b/c
of
the high phosphorus and sulfur content.

i hope it didnt make it sound too complicated....i tried to simplify
it for
you. hope i answered your question.

one love,
matt

>I'm learning about the acid/alkaline issue. I have what may appear to be a
>dumb question. I'm looking for, and have not yet found, an explanation of
>how/why it is that a something like a lemon, that is so acidic, has an
>alkaline effect on the body. I understand that it has alot of calcium
>which is an alkaline mineral, but what happens to the acidity of the
>lemon? is it simply that it gets digested and its acidity has no further
>impact on the body? and about asparagus which are slightly acidic.