The objective of this study was to evaluate the effect of variations in milk protein composition on milk clotting properties and cheese yield. Milk was collected from 134 dairy cows of Swedish Red and White, Swedish Holstein, and Danish Holstein-Friesian breed at 3 sampling occasions. Concentrations of alphaS1-, beta-, and kappa-casein (CN), alpha-lactalbumin, and beta-lactoglobulin (LG) A and B were determined by reversed phase liquid chromatography. Cows of Swedish breeds were genotyped for genetic variants of beta- and kappa-CN. Model cheeses were produced from individual skimmed milk samples and the milk clotting properties were evaluated. More than 30% of the samples were poorly coagulating or noncoagulating, resulting in weak or no coagulum, respectively. Poorly and noncoagulating samples were associated with a low concentration of kappa-CN and a low proportion of kappa-CN in relation to total CN analyzed. Furthermore, the kappa-CN concentration was higher in milk from cows with the AB genotype than the AA genotype of kappa-CN. The concentrations of alphaS1-, beta-, and kappa-CN and of beta-LG B were found to be significant for the cheese yield, expressed as grams of cheese per one hundred grams of milk. The ratio of CN to total protein analyzed and the beta-LG B concentration positively affected cheese yield, expressed as grams of dry cheese solids per one hundred grams of milk protein, whereas beta-LG A had a negative effect. Cheese-making properties could be improved by selecting milk with high concentrations of alphaS1-, beta-, and kappa-CN, with high kappa-CN in relation to total CN and milk that contains beta-LG B.

Lipid auto-oxidation in milk is affected by a complex interplay of pro-and antioxidants. Several of these compounds are also important nutrients in the human diet and may have other physiological effects in the gastrointestinal tract and other tissues. Among antioxidative enzymes superoxide dismutase catalyses the dismutation of superoxide anion to hydrogen peroxide. The degradation of hydrogen peroxide can be catalysed by catalase and the selenoprotein glutathione peroxidase. The latter enzyme can also degrade lipid peroxides. Lactoferrin may have an important role by binding pro-oxidative iron ions. The occurrence of different forms of these antioxidative proteins in milk and available data on their functional role are reviewed. More remains to be learnt of individual compounds and as an example the potential role of seleno compounds in milk is virtually unknown. Antioxidative vitamins in milk can provide an important contribution to the daily dietary intake. Moreover vitamin E and carotenoids act as fat-soluble antioxidants, e.g. in the milk fat globule membrane, which is regarded as a major site of auto-oxidation. Vitamin C is an important water-soluble antioxidant and interacts in a complex manner with iron and fat-soluble antioxidants. The concentrations of these compounds in milk are affected by cow feeding rations and milk storage conditions. Since milk contains a number of antioxidants many reactions are possible and the specific function of each antioxidant cannot easily be defined. There are indications that other compounds may have antioxidative function and measurement of total antioxidative capacity should be a useful tool in evaluating their relative roles.

No abstract

No abstract

The use of cancer biomarkers to anticipate the outlines of disease has been an emerging issue, especially as cancer treatment has made such positive steps in the last few years. Progress in the development of consistent malignancy markers is imminent because advances in genomics and bioinformatics have allowed the examination of immense amounts of data. Osteopontin is a phosphorylated glycoprotein secreted by activated macrophages, leukocytes, and activated T lymphocytes, and is present in extracellular fluids, at sites of inflammation, and in the extracellular matrix of mineralized tissues. Several physiologic roles have been attributed to osteopontin, i.e., in inflammation and immune function, in mineralized tissues, in vascular tissue, and in kidney. Osteopontin interacts with a variety of cell surface receptors, including several integrins and CD44. Binding of osteopontin to these cell surface receptors stimulates cell adhesion, migration, and specific signaling functions. Overexpression of osteopontin has been found in a variety of cancers, including breast cancer, lung cancer, colorectal cancer, stomach cancer, ovarian cancer, and melanoma. Moreover, osteopontin is present in elevated levels in the blood and plasma of some patients with metastatic cancers. Therefore, suppression of the action of osteopontin may confer significant therapeutic activity, and several strategies for bringing about this suppression have been identified. This review looks at the recent advances in understanding the possible mechanisms by which osteopontin may contribute functionally to malignancy, particularly in breast cancer. Furthermore, the measurement of osteopontin in the blood or tumors of patients with cancer, as a way of providing valuable prognostic information, will be discussed based on emerging clinical data. (Cancer Epidemiol Biomarkers Prev 2007;16(6):1087 -97)