Milk

What is milk?

Milk as a food

"Drinking milk is the product obtained from the regular, uninterrupted and complete milking of animals in good health and nutrition " (RD 9/5/29 n. 994 and subsequent modifications).

It is important that milking is uninterrupted and complete to guarantee:

• animal health (otherwise it could suffer from mastitis)
• the quality of the food (the composition of the milk varies during milking, enriched with lipids as it comes to an end).

In order for the milk to be free from defects and harmful substances permeated by blood, as well as from a nutritional point of view, it is also important that the animal is in good health and nutrition.

By law, the generic term "milk" indicates that of cow (scientific name Bos taurus ), while for milks of different origin it is necessary to specify their origin (eg goat's milk, sheep's milk, donkey's milk, etc.).

Deep Readings

Animal Milk

Donkey's milk Buffalo milk Goat's milk Sheep's milk Powdered milk and concentrated milk Skimmed and partially skimmed milk

Vegetable Milk

Soya milkVideo Recipe to make it at home Rice milkVideo Recipe to make it at home Almond milk Video Recipe to make it at home Oat milkVideo Recipe to make it at home Coconut milk Video Recipe to do it at home

Milk and Health

Milk allergy Lactose intolerance Lactose in food Lactose-free milk Raw milk Whole milk or raw milk? Whole or skimmed milk: Which to choose? Milk, dairy products and osteoporosis Cholesterol in milk and derivatives

Breast milk and breastfeeding

Breast milk for woman's milk Colostrum Production of breast milk Proteins and antibodies in breast milk Minerals and vitamins in breast milk Breast feeding Breast milk production Artificial milk Artificial milk composition Milk for premature babies Therapeutic or special milk

Milk derivatives

Butter Yoghurt Dairy Products Buttermilk Fermented Milk Milk Protein Cheese Nutritional Values ​​Milk and Derivatives

Nutritional Properties

Description

Milk is an opalescent biological liquid, with a sweet taste and a delicate odor, of complex composition.

The appearance and the organoleptic characteristics of the milk change considerably according to the type and processing. Very important factors are:

• Animal of origin
• Skimming level
• Possible application of heat treatments for conservation
• Type of heat treatment.

Chemical properties

From the chemical-physical point of view, milk is a watery dispersion of many substances found:

• IN SOLUTION: lactose, mineral salts, water-soluble vitamins, gas
• IN COLLOIDAL SOLUTION: whey proteins, phosphates
• IN DISPERSION: casein
• IN SUSPENSION: cells, microorganisms
• IN EMULSION: fats, fat-soluble vitamins.

The difference between colloidal solution, dispersion and suspension lies in the particle size, which grows going from suspension colloidal solution; in milk we also find substances in emulsion, represented by fats and fat-soluble vitamins (they are found in small droplets dispersed in the aqueous phase, in which substances in solution, colloidal solution, dispersion and suspension are present).

Nutritional characteristics of cow's milk

The extraordinary richness in nutrients of cow's milk makes it come close, perhaps more than any other food, to the concept of " complete food "; except for newborns in the first 5 or 6 months of life (which still require a specific food), the milk has two important limitations, consisting of:

• reduced iron content (instead abundant in the maternal one)
• low calorific value (if we take cow's milk as a reference, about 4 liters would be needed to meet the daily energy needs of an adult).

Milk is a product that is part of the II fundamental group of foods (milk and derivatives); as such, it is a good source of high biological value proteins, specific vitamins and minerals.

It has a variable energy intake based on the level of skimming, but it is still quite low (from 35 to 65 kcal / 100 g). The calories come mainly from lipids (in whole milk) or carbohydrates (in skimmed milk).

Fatty acids are mainly saturated, peptides with high biological value (rich in essential amino acids) and simple carbohydrates (lactose disaccharide). Cholesterol is higher in whole milk than skimmed milk. The fibers are absent.

As for the vitamin profile, milk is particularly rich in riboflavin (vit B2) and, especially the whole one, of vitamin A (retinol and equivalents); there are interesting levels of many other components of group B. Regarding mineral salts, considerable amounts of calcium and phosphorus are appreciated; the various microelements (zinc, selenium, etc.) are not to be ignored.

Milk, thanks to the availability of at least 3 levels of skimming, is a food that can be contextualized in all diets. The content of calcium and phosphorus can be useful for achieving the recommended daily ration for growing subjects and those in old age; remember that the deficiencies of calcium and vitamin D are two risk factors for failure to achieve peak bone mass and osteoporosis. To fill the vitamin D deficiency, some types of "reinforced" dietary milk are available today. Note : another widespread dietetic strengthened milk is the one added with omega 3.

Whole milk should be limited significantly or replaced with leaner ones in case of overweight and hypercholesterolemia. Furthermore, containing lactose, it does not lend itself to the diet of people lacking in intestinal lactase enzyme; said intolerant, if they introduce excessive amounts of disaccharide, these people risk developing annoying gastro-intestinal symptoms (diarrhea, intestinal cramps, etc.). The solutions to this problem are 3:

• Eliminate milk and derivatives from your diet, adjusting your diet accordingly and possibly taking supplements
• For the less sensitive intolerant, replace milk with yogurt
• Replace normal milk with dietary delactosate (predigested with lactase enzymes).

Milk is a potentially vegetarian but not vegan food; it is also subject to precise religious regulations (for example in Judaism).

The average portion of milk is about 200 ml per day, although this value can change significantly with reference to the intake of yogurt or other similar derivatives (which normally could be consumed in quantities of 125-250 g / day).

Variables

What factors influence the chemical composition of milk?

The composition of milk is equally complex and can vary depending on various factors.

Genetic factors

Man has always selected animals with high milk productivity, both in terms of quantity and quality (to obtain a food rich in fats and / or proteins); on the other hand, it has also selected the most resistant species to work and those most suitable to provide quality meats.

All these elements explain the compositional differences of milks coming from different breed cows.

Physiological state of the animal

It depends primarily on the lactation phase.

The cow begins to produce milk after the birth of the calf and continues for a variable time, which lasts on average 200-220 days; the quantity of milk produced, which can reach 7, 000 kg, clearly exceeds the needs of the calf (estimated at around 1, 000 kg) and for this reason it can be largely used for human consumption.

As with all mammals, including humans, cow's milk varies its composition at different stages of lactation; in the first week a milk rich in immunoglobulins, antibodies and proteins (called colostrum) is produced, which guarantees the calf a rapid recovery and growth after birth. The chemical composition of milk then begins to vary, until it turns into mature milk, richer in sugars and fats, and used for human nutrition.

Animal health status

Significant changes in milk composition occur in conjunction with mastitis; this breast infection causes reduced milk production and all the components that derive from the mammary gland, such as water, sugars and proteins, while the factors that permeate from the blood, such as sodium chloride and antibodies, increase.

Breeders realize that the animal is mastitic because the pH of milk is higher than the norm, therefore higher than 6.8.

Environmental factors

Strong temperature changes and environmental stresses of different nature influence the milk production of the animal, both in quantitative and qualitative terms.

Supply

Generally the feeding of the cow is based on fodder, often supplemented with soy flour and cereals to increase the protein and lipid content of milk. Only a correct, balanced and optimal diet guarantees maximum productivity in relation to the genetic heritage of the cow.

Technological factors

During milking, the milk changes its composition and is enriched with lipid substances as it comes to an end (this aspect, common also to a woman's milk, determines satiety in the calf).

The various milking fractions must therefore be combined and mixed.