Milk intolerances

Nutritional value of lactose-hydrolysed milk: protein quality after some industrial processes

The nutritional protein quality of lactose-hydrolysed milk after some industrial processes was studied with N balance experiments on growing rats.

Ultra-high-temperature sterilization and evaporation at 25 °C did not influence the nutritional value significantly, whereas spray-drying under conditions usually used for ordinary milk gave a considerable reduction in protein quality. This was caused mainly or entirely by loss of biologically availabe lysine.

History and current status of infant formulas

Formulas that approximate the composition of human milk are widely used as the sole source of nutrients for infants during the first months of life. Such formulas contain milk, soy, or meal proteins, or protein hydrolysates together with those forms of fat carbohydrate, vitamins, and minerals shown to be bioavailable to the infant. Legislation concerning nutrient composition and quality assurance of products labeled as infant formulas has been enacted by Congress. Governmental and industrial standards also help to assure microbiological safety and stability. Problems of nutrient composition and adverse reactions have occurred during the evolution and development of infant formulas. Problems concerning nutrient deficiency are now almost unknown, but adverse reactions of individuals to specific formula ingredients continue. Accurate information on composition and related nutritional properties of infant formulas is essential for their effective use and for the avoidance of undesirable complications.

Plasma amino acid response to single test meals in humans. VI. Determination of available lysine

The plasma amino acid response to single test meals in young adults was used to determine the amount of physiologically available lysine in heat-treated milk samples. The plasma amino acid responses were evaluated as PAA ratios according to a modified calculation procedure based on the method proposed by Longenecker and Hause. The amount of available lysine was determined by two separate series of single-meal tests. In the first, a relationship was established between the plasma amino acid response (PAA ratio) and the dietary level of lysine (given as synthetic amino acid mixtures). This relationship could be described by linear regression (r = 0.90). This regression line was then used to quantitatively evaluate the lysine PAA ratios obtained from single test meals with heat-treated milk samples. The heat-treatment of the milk samples caused a marked reduction of the amount of physiologically available lysine. The quantitative estimates obtained by the present plasma amino acid technique were in good agreement with determinations of available lysine in the same milk samples based on rat bioassay and chemical analysis.

The nutritional and physiological impact of milk in human nutrition

The nutritional value of milk as an important source of energy, high-quality protein, calcium, and riboflavin has been recognized for many years. Currently, the widespread use and promotion of milk in the U.S. as well as developing countries has been questioned. This review examines the nutrient composition of dairy products, factors that account for variability in composition of milk, milk processing, preservation, quality control, and contaminants (such as minerals, radionuclides antibiotics, microorganisms and their metabolites, herbicides, and insecticides) in milk. Consumption patterns for milk and evidence for its nutritional value, especially in children, are presented. Milk consumption has been related to disease or conditions such as atherosclerosis, milk allergy, lactose intolerance, anemia, dental problems, and others. Recent recommendations for dietary changes for individuals in the U.S. and other developed countries could affect the use of milk. In addition, the use of feeding programs in the U.S. and developing countries which are based primarily on milk has been criticized. The preparation of new types of milk designed to offset certain difficulties encountered with cow's milk are now being evaluated in humans.