The laboratory’s work is based on a subjective assessment of the organoleptic properties of water. Below is a list of different bottled waters. Everyone can evaluate the taste of the selected water on a 5-point scale. Organoleptic assessment of water is a generalized result of the assessment of its quality, performed with the help of human senses.
SIMPLIFIED WATER VALUES ASSESSMENT SYSTEM
To determine the value of water, you need to calculate the total score using the table:
|Fresh spring water (in an ecologically clean area)||0|
|Fresh spring water (there are industrial enterprises in the radius of 5 kilometers around the spring)||1|
|Bottled spring water||1|
|Water from the well, depth > 100 meters||1|
|Water from the well, depth < 100 meters||2|
|Bottled water from the well, which has undergone various technological treatments||2|
|Water from a main water supply||3|
|Water from a main water supply in a city with a population of more than 1 million||4|
|Water from a main water supply with a smell / taste of chlorine||2|
|Water from a main water supply with a smell / taste of ammonia||1|
|Water from a main water supply with a smell / taste of hydrogen sulphide||1|
|Water with an unclear taste or smell||1|
|Bottled water from sources not described above||1|
|Water after boiling||1|
|Water with temperature over 40 ° C||1|
Example of calculation: Water from a main water supply in a city with a population of more than 1 million (4 points) + Water from a main water supply with a smell / taste of chlorine (2 points) + Water from a main water supply with a smell / taste of hydrogen sulphide (1 point) + Water after boiling (1 point) = 8 points.
The higher the total score, the less valuable water for the organism.
A large volume of scientific research results were used to create this table. Common factors were identified for some or other waters and their average level of value for the organism was determined.
Let us recall some basic parameters responsible for organoleptic properties of water:
Сolor of water.
Сolor of water is determined by concentration of the coloring substances, in particular the compounds of ferric iron. Water color is determined by comparing with the standards. Significant color of water strongly affects organoleptic properties and is one of the negative signs to be paid attention. Color is evaluated on a 100-degree scale of water color.
Smell of water.
Smell of water is evaluated on a 5-point scale (0 – no smell, 1 – very weak, 2 – weak, 3 – noticeable, 4 – distinct, 5 – very strong) (State Standard 3351-74). In the case of drinking water, a smell of not more than 2 points is allowed. This refers to the smell detected by a consumer, if he pays attention to it.
Smell is divided into two categories according to it’s origin:
1) Natural origin (earthy, putrefactive, moldy, peaty, grassy, etc.);
2) Artificial origin (Petroleum products, chlorine, acetic, phenolic, etc.)
Taste and after-taste.
Taste is divided into 4 types: sweet, bitter, sour, salty. The other taste sensations are related to after-taste. Intensity of taste and after-taste, as well as smell of water, is assessed on a similar 5-point scale.
Turbidity is determined using photometric methods of research. Therefore, turbidity is an objective assessment. In the practice of organoleptic research it is possible to operate only with indicators of water color.