Mature human milk and colostrum contain 12 to 13 g/L and 22 to 24 g/L of oligosaccharides, respectively. Oligosaccharides constitute the third largest component, after lactose and lipids, of the dry matter of human milk. The structures of at least 93 human milk oligosaccharides have been determined to date, while mass spectra data have suggested the presence of more than 130 oligosaccharides in human milk or colostrum. The 93 oligosaccharides can be grouped into 12 series based on their core units. These oligosaccharides are resistant to enzymatic hydrolysis by the intestinal lactase of brush border and there is evidence that the major part survives passage through the small intestine and enters the colon where they are fermented by colonic bacteria. A small fraction of human milk oligosaccharides is absorbed intact, perhaps by receptor-mediate endocytosis, some of which is excreted in the urine. At the colon, the unabsorbed oligosaccharides are believed to act as prebiotics, stimulating the growth of bifidobacteria, and as soluble receptor analogues that inhibit the attachment of pathogenic microorganisms to the colonic epithelial cells. There is an evidence that metabolic activity of the bifidobacteria reduces the colonic pH, which has the effect of inhibiting the proliferation of pathogenic organisms such as Shigella flexneri and Escherichia coli. Although a specific oligosaccharide responsible for stimulating the growth of bifidobacteria was not identified, Kitaoka et al. recently, presented a new hypothesis, based on a novel metabolic pathway for galactose in bifidobacteria, which proposed that Gal(β1-3) GlcNAc(lacto-N-biose I) structures, which are found in type I human milk oligosaccharides, act as specific bifidus factors. Pathogenic bacteria and viruses, to begin their infection, need to attach to the colonic mucosa, which they do by adhering to specific carbohydrate structures of glycoconjugates on the surface of the colonic epithelial cells. Because many milk oligosaccharides contain structural units that are homologous to these carbohydrate structures, it has been suggested that they act as soluble receptor analogues, inhibiting the adhesion of the pathogens, these preventing infection. The observation of 2′-fucosyllactose inhibits the binding of Campylobacter jejuni to H(O) antigen (Fuc(α1-2) Gal(β1-4)GlcNAc) in the infant colon is noteworthy, because this trisaccharide is the most abundant oligosaccharide in human milk. The absorption of small part of human milk oligosaccharides follows that they may alter protein-carbohydrate interactions at systemic level. For example, recent studies suggest that human milk oligosaccharides interfere with the adhesion of neutrophils to vascular endothelial cells and to platelets. These effects appear to be based on structural resemblance of some human milk oligosaccharides to the glycoprotein ligands of selectins.
Effective management of risks arising from microbial hazards in foods is technically complex. Recently, risk analysis, involving its component parts of risk assessment, risk management and risk communication, has been introduced as a new approach in evaluating and controlling microbial hazards along with the entire food chain to help protecting the health of consumers and ensure fair practices in food trade in the Codex Alimentarius Commission. Due to the recent advancement of quantitative microbiological risk assessment, it is possible to link the stringency of microbiological risk management (MRM) and the intended level of protection of public health. In addition, the introduction of emerging MRM metrics, namely Food Safety Objective (FSO), Performance Objective (PO), and Performance Criteria (PC) will enhance the risk based MRM activities. In this review, the history and current activities regarding microbiological risk management within CAC are reviewed and discussed.
There have been numerous evidences indicating that milk proteins influenced various immune functions. Here, we review the milk proteins playing the important roles. Recent reports have shown that LF enhanced anti-microbial, anti-viral and anti-tumor immune activities when orally administered. We report here that orally administered bovine LF (bLF) increases peripheral NK cell and augments the NK cell activity. Oral administration of bLF immediately induced the production of IL-18 in the intestinal epithelium, and the elevation of portal IL-18 levels. Furthermore, oral bLF administration augmented the expression of type-I IFNs in Peyer's patches and mesenteric lymph nodes. Collectively, these results indicated that orally administered bLF stimulated intestine-associated immune functions, including the production of IL-18 and type-I IFNs, and then raised the NK cell activity. All classes of immunoglobulin are found in milk. Human milk antibodies are primarily of the secretory IgA type, while the major antibodies of bovine milk are IgG type. Secretory IgA consists of two molecules of IgA bound to a protein, the secretory component. Human milk contains secretory IgA antibodies against microorganisms which have exposed the mother's gastrointestinal and respiratory tract. Milk contains a number of other proteins participating in defense in addition to lactoferrin and antibodies. Lactoperoxidase has a wide range of biological functions including antimicrobial and immuno-modulatory effects. Lysozyme which cleaves peptidoglycans of bacterial cell walls achieves a bactericidal effect.
Milk containers have passed through various changes, since milk was released in Japan in the early Meiji era. Three kinds of containers are available such as glass, paperboard and plastic types, although the plastic container is not popular commercially. Various technologies have been invented for these containers to improve functions in response to their characteristics. Milk cartons have been improved on demand of universal design, such as discrimination with notch and easy peeling at the top of the carton. Additionally devices to promote recycling of paperboard are introduced for the protection of environment. In some cases the shield printing technology is used to protect from the light-induced flavor deterioration. Ministerial ordinance on milk and milk products was revised in October 2007; the use of PET container to milk was authorized. The deregulation by the ministerial ordinance revision is an opportunity for the milk container diversification, although there still have some problems to be solved with respect to container itself and investment cost of facilities in order to commercialize large-volume PET milk containers.
Functional attributes of dairy products are being discovered as functional protein, peptides, probiotics, and oligosaccharides. These functional components are investigated to determine their nutritional and functional aspects for our health. Nutrigenomics is research focusing on identifying and understanding molecular-level interaction between nutrients and other dietary bioactives with the genome. By understanding how nutrients interact with the genome, better dietary regimens may be designed or novel treatment of important diseases may be addressed. Nutrigenomics utilizes such tools and approaches as microarrays and genomics, proteomics, metabolomics and bioinformatics to improve diet and health. In this article, we describe the current studies of nutrigenomics and molecular analysis of functional components from dairy products. This research will reveal the effects of nutrients on the molecular-level processes in the body and document variable effects of nutrients under different conditions.
Trans fatty acids are isomers of cis fatty acids. There are two main dietary sources of trans fatty acids- those derived from ruminant products such as milk, beef meat and those formed by the partial catalytic hydrogenation of vegetable and marine oils in the production of solid and liquid fats used in many industrially produced foods such as baked goods, frying fats and margarines. From epidemiological studies, increased coronary heart disease risk was associated with trans fatty acids. In addition, an excessive intake of trans fatty acids increased LDL-cholesterol level and decreased HDL-cholesterol. This paper reviews the outline of the trans fatty acids, the relation to disease and the intake situation of the trans fatty acids.