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Water |
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Water |
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It's a chemical compound between
the most diffuse in nature. Its molecule is formed from two hydrogen atoms
bound to an oxygen one: composition conferring it the characteristics of a
dipole,
that is a substance |
Mineral water: |
with a not uniform distribution of electrical
charges.
From that it derives the property of this compound to exercise a great dissolvent power
with the saline substances. The water has a dissolvent power also with gases and,
therefore, it constitutes a habitat fitted to numerous forms of life
in a position to use oxygen dissolved in it . The saline content of water expresses with the term
" total hardness ". Such content is measurable with " the French degree" (1g of
calcium carbonate every 100 liters), or through a process of evaporation and calcination
(heating of residual solid) at 180°C. This value, usually expressed in
mg/liter, is called
"dry residue " and it is a quality index of mineral waters.
The water presence in the food favors their
degradation through the
microrganisms. A method of conservation of the raw materials adopted
since the ancient times consists of diminishing the available water amount
for the bacterial increase, either through the drying process, or through
the salting, the sugar process, the blackening with smoke etc. The
aliments
so treated therefore are defined " at reduced content of free water " or "
at water low activity ". Also the modern industrial processes of lyophilization deprive the food
of the water contained in it, making it practically unattackable from
the microrganisms. The points of boiling and freezing of the water are influenced from the presence
of salts dissolved in it : the salty water, for example, boils later than
the sweet one. The mountain waters rich of carbonates, possess such
characteristics to make them hardly fitted either for baking cereals and
legumen, to which they confer particular hardness, or for the formation
of foam through detergents, for their tendency to salification
soaps.
characteristic.
Generally, the mineral waters subdivide in
low mineral content water (dry residue inferior to 200 mg/liter), medium
mineralcontent water (dry residue between 200 and 1,000 mg/liter). Being subject to authorization from
the Ministry of Health and from the authority of the region where the
source is situated, they must correspond to determined requirements and,
in particular, they must have in their label the qualitative and
quantitative composition of the single dissolved mineral elements , as
well as the hardness, the dry residue, dissolved gases , pH (the degree of
acidity) and
the specific electrical conductivity. Moreover, they must be certified
bacteriologically pure and be equipped of therapeutic
properties, for
example on the reciprocation or on the digestive processes. The product must
be bottled on the place, by the source, which must have characteristics of stability of chemical
composition, temperature and capacity, also in the periods of running
dry. The mineral waters are distinguished then in natural (not sparkling),
natural sparkling and sparkling with adding of carbon dioxide. These
last ones are not to be confused with the water called "soda water", that it is an
artificial product.