The grease or lipidi, together to the proteine and sugars, are a group of important nourishing substances a lot for our organism.
They, in fact:
- they constitute of the irreplaceable shapes of energy;
- they represent the principal source, if not the only one, of supplying of fat acids essential, indispensable for one to regulate physiology of our organism (es.: operation of cellular membranes and synthesis of the prostaglandine that regulate the activity of some hormones);
- they are the ideal and indispensable supports of an important group of vitamins, those liposolubili (To, D, and and K)
- they are the greater aromatic sources of the alimony;
- they regulate the centers deila hunger cantribuendo to the satiety feeling that is perceived after a normal meal.
The greases can be distinguished in vegetables and animals. In both cases, we can have solid fat people and liquids. Between the solid fat people of animal origin we remember the butter and the strutto, while between those of origin vegetable the margarina. Between the fat liquids, sayings commonly oils, we remember the oil in the first place extravergine of olive, the best one between commercialized oils than olive; beyond to they they come also consumed oils extracted from various seeds of agrarian plants: the seed wings.
According to the data of the FAO (Food and Organization Agricultures - United Nation for agriculture and the feeding) a population comes considered in good alimentary conditions if every day medium availability of 2750 kcal (chilocalorie) totals has one; of they, those coming from the fat people would not have to exceed 30% (that it corresponds to 80.8 grams).
The concept of caloric necessity is somewhat relative. However, for the medium Italian, and be calculated every day requirementses of approximately 2400 kcal, with a correspondent requirementses in fat people of approximately 70 grams.
However the presence of fat substances in our feeding would have above all to be tied to their quality, rather than to the amount.
The difference between several the fat people consists in the various chemical camposizione. While in the greases
animals prevail fat acids saturate (that they confer solidity to the same fat person: you see butter, strutto etc.) those vegetables are constituted in prevalence from fat acids insaturi, that they confer fluidity and limpidezza to the product. The fat acids legacies to the glycerin constitute the trigliceridi that they represent the preponderant part of the fat matters. The fraction of they tied to the glycerin does not constitute the so-called free acidity, easy perceivable to the taste, as an example, in oils of insufficient pregio.
In the olive oil, the fat acids insaturi are of two types: monoinsaturi and polinsaturi; these last ones are also essential sayings why they cannot be synthetized from the human organism. And own this the reason for which he is advisable assumerli in our diet, but in percentages balanced, the same ones that the good oils of olive are found in, that appears particularly fluid and with melting point much bottom, beyond possessing important biological property a lot.
In olive oils vergini, beyond to fat acids, other substances are present numerous: hydrocarbons, tocoferoli, polifenoli, steroli, alcoli, pigments, vitamins and waxes; they have some nourishing property and confer to the oil, the sapore, the aroma and the resistance to the oxidation (as an example, irrancidimento and ossidativa degradation during the baking extended to high temperatures).