Liquid Whole Milk

Scientific investigation in the field of modern nutrition has made clear the fundamental reasons why milk is an essential part of the human diet.

Fluid milk, the chief product of the dairy industry, is made from raw milk (obtained from healthy cows) and has been modified only to the extent that it has been heat treated (pasteurization, cooling) and homogenized. Standardization of the milk fat content is practiced in order to produce the three most common varieties of fluid milk: whole (3.25% fat), partly skimmed (2% fat or 1% fat) and skimmed (0.1% fat) milk. Pasteurization is the minimum and mandatory heat treatment for fresh milk and is required for public health reasons. Cooling and storage of pasteurized milk at 4 - 5.C throughout the distribution chain is necessary for quality assurance purposes. Homogenization improves the desirability of milk as a drink by giving it a full body, a richer taste and a whiter appearance. Homogenization also prevents cream separation.

Cow's milk is one of the most important sources of healthy and functional food ingredients. Its full potential can be appreciated by taking into consideration its wide variety of food industry applications. Fluid milk, in forms ranging from whole milk to skimmed milk, is the main ingredient purchased by dairy processors and manufacturers of yogurt and other high quality fermented milk products. In addition, cheese plants and frozen dessert manufacturers purchase fluid milk in bulk quantities. Its unique functional properties, flavour, nutrition and multiple end uses in further processing are well documented.

Milk is a complex biological fluid consisting of seven main components: water, fat, protein, sugar (lactose), minerals, vitamins and enzymes. It could also be described as a true aqueous solution of lactose, salts and a few other minor compounds, which is emulsified with fat and supports a colloidal dispersion of proteins. The opacity of milk is due to its content of suspended particles of fat, proteins and certain minerals. The colour varies from white to yellow according to the colouration (carotene content) of the fat. Skimmed milk is more transparent with a slightly bluish tinge. Milk of a good flavour has a pleasant, slightly sweet taste, and no odour. It is an excellent source of calcium, phosphates and riboflavin. Vitamin A and D are currently added to whole milk, partly skimmed and skimmed milk.

Microbiological standards for pasteurized milk require that the product be free from Salmonella, Listeriaand antibiotics. One millilitre must show a maximum Standard Plate Count of 100,000 colony-forming units (CFU), a maximum of 10 Coliforms CFU and a maximum of 10 Psychrotrophic organisms CFU.  Psychrotrophic refers to cold-tolerant bacteria capable of growing at 4-15.C.

The principal end uses for milk as an ingredient are flavoured dairy drinks, frozen desserts, set or stirred yogurts, cheeses, creams and fortified milks. Various food industry applications include coffee whiteners and creamers, whipped toppings, bakery products, meat products, instant breakfast preparations, instant beverages, puddings, pasta, cheese products, ice cream, soups and sauces, spreads, infant foods, sports drinks, nutritional bars, etc. In the bakery industry, milk is the primary liquid ingredient used in the making of doughs and cakes mixes. It increases the absorbing qualities of the doughs and gives richness to cakes because of its fat content as well as its natural sugar content (lactose).

Milk as an ingredient has been used in milk chocolate since 1876 in Switzerland when companies started making edible chocolate in addition to their chocolate beverage products. Apart from its nutritional role, milk continues to contribute to the gloss, shelf life, flavour, texture and colour of the final chocolate product. The confectionery industry represents one of the key markets for liquid whole and skim milk. Edible milk chocolate, toffee and caramel would likely not exist if not for the use of milk as an essential ingredient.

The application of dairy ingredients in nutraceutical and functional foods has become very popular in recent years. Regular reports are being published on the on-going research and development that is taking place with regards to the unique range of functional and active ingredients derived from milk.

Milk is a highly nutritious and functional food. Several desirable properties are achieved by incorporating whole milk in a recipe or formulation. For the further processor, the major components of milk, i.e. water, fat, proteins and lactose are probably of greatest importance since most of the functional properties reside with these individual components.