Milk is an essential food at any age of life. Its nutritional quality comes from its particular composition:
it is the most important constituent of the dry matter of milk. Milk owes its mild and slightly sweet flavor to lactose, a carbohydrate that is a particularly preferred fuel for the brain and muscles.
It also has a very Significant additional nutritional advantage: it optimizes the proper use of dairy calcium by the body, by increasing its absorption in the intestine, as well as the assimilation of milk proteins.
Lipids essentially have an energy role. Characteristics of milk fat:
- Saturated fatty acids: they have interesting specificities. Short-chain saturated fatty acids are particularly well digested and quickly used as a source of energy by the body. Others with longer chains play a role in the development of a child’s nervous system.
- Unsaturated fatty acids: they are composed of monounsaturated fatty acids known for their neutral effect on the cardiovascular system and polyunsaturated fatty acids. Milk contains little of it, but its contribution to essential fatty intakes (linoleic acid and alpha-linolenic acid participating in the maintenance of membrane structures) should not be neglected.
milk proteins are abundant and have high nutritional values, which makes milk a food of vital necessity. Indeed, our body uses proteins for its maintenance.
Every day, throughout life, it destroys and renews some of the proteins, especially during growth, pregnancy, breastfeeding, and old age to make new tissue.
milk contains a large part of the minerals essential for the body, the most important are:
- Calcium: 1.2 g.l-1. The calcium circulating in our blood participates in the renewal of all the cells in our body, throughout life. It performs many functions in vital organs and plays an important role in the maintenance of our skeleton.
- Phosphorus: 0.9 g.l-1
- Potassium: 1.5 g.l-1
- Magnesium: 0.13 g.l-1
milk is an important natural source of group B vitamins:
- vitamin B1 or thiamine, essential for the proper functioning of the nervous and muscular systems and for the metabolism of sugars (carbohydrates).
- vitamin B2 or riboflavin, necessary for tissue renewal and maintenance. It is also essential for the transformation of food into energy. It plays a role in vision and promotes growth.
- vitamin B9 or folic acid participates in the formation of red blood cells and nerve cells to prevent certain forms of anemia (iron deficiency).
- vitamin B12 or cobalamin participates in the formation of nerve cells
Milk also provides fat-soluble vitamins:
- vitamin A or retinol: is active in the transmission of light through the retina of the eye, plays a role in the protection of the skin and mucous membranes, and has an effect on growth.
- vitamin D or calciferol: is the anti-rickety vitamin. It is involved in the metabolism of calcium and phosphorus.
The different types of existing milk
The classification is established according to two main criteria (fat content and heat treatment) which define the different kinds of milk:
- Whole milk: at least 3.5% fat per liter
- Semi-skimmed milk: between 1.5 and 1.8% fat per liter
- Skimmed milk: less than 0.5% fat per liter
- Milk containing a specific% fat: the fat content must be mentioned.
- Raw milk: the milk is not subjected to any treatment except refrigeration after milking
- Microfiltered fresh milk: the milk is treated by microfiltration (use of a porous membrane to retain the microbial flora of the skimmed milk without modifying its physicochemical composition)
- Fresh pasteurized milk: Milk is heated to 72 ° C for at least 15 seconds before being cooled to below 6 ° C.
- Sterilized milk: a simple sterilization technique in which the milk is heated to 115 ° C for 15 to 20 minutes before being cooled.
- UHT sterilized milk: Ultra High-Temperature sterilization technique in which the milk is heated to 140 ° C for 2 seconds.
Other criteria may also come into play in the classification of milk:
- Enrichment with nutrients (vitamins, proteins, minerals, etc.)
- Changes in lactose levels
- Organic milk
- Condensed milk (sweetened or not)
- Milk in its dehydrated form (milk powder)
- Infant milk are complex recipes that aim to meet the specific needs of infants and young children