Nucleotides, nucleosides and nucleobases belong to the non-protein-nitrogen (NPN) fraction of milk. The largest amounts of ribonucleosides and ribonucleotides ± ribose forms only were considered in this review ± were measured directly after parturition in bovine milk and other ruminants as well as in the milk of humans. Generally, concentrations of most of the nucleos(t)ides tend to decrease gradually with advancing lactation period or nursing time. The species-specific pattern of these minor constituents in milk from different mammals is a remarkable property and confirms, at least, the specific physiological impact of these minor compounds in early life. The physiological capacity of these compounds in milk is given by the total potentially available nucleosides. The main dietary sources of nucleos(t)ides are nucleoproteins and nucleic acids which are converted in the course of intestinal digestion into nucleosides and nucleobases the preferred forms for absorption in the intestine. Thus, nucleosides and nucleobases are suggested to be the acting components of dietary and/or supplemented nucleic acid-related compounds in the gut. They are used by the body as exogenous trophochemical sources and can be important for optimal metabolic functions. Up to 15 % of the total daily need for a breast-fed infant was calculated to come from this dietary source. Concerning their biological role they not only act as metabolites but are also involved as bioactive substances in the regulation of body functions. Dietary nucleotides affect immune modulation, e.g. they enhance antibody responses of infants as shown by a study with more than 300 full-term healthy infants. Dietary nucleos(t)ides are found to contribute to iron absorption in the gut and to influence desaturation and elongation rates in fatty acid synthesis, in particular long-chain polyunsaturated fatty acids in early stages of life. The in vitro modulation of cell proliferation and apoptosis has been described by ribonucleosides, in particular by modified components using human cell culture models. Due to the bio-and trophochemical properties of dietary nucleos(t)ides, the European Commission has allowed the use of supplementation with specific ribonucleotides in the manufacture of infant and follow-on formula. From the technochemical point of view, the ribonucleoside pattern is influenced by thermal treatment of milk. In addition ribonucleosides are useful indicators for quantifying adulterations of milk and milk products.

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We investigated the ability of Trametes versicolor and Pycnoporous cinnabarinus to metabolize triclosan. T. versicolor produced three metabolites, 2-O-(2,4,4-trichlorodiphenyl ether)-␤-D-xylopyranoside, 2-O-(2,4,4-trichlorodiphenyl ether)-␤-D-glucopyranoside, and 2,4-dichlorophenol. P. cinnabarinus converted triclosan to 2,4,4-trichloro-2-methoxydiphenyl ether and the glucoside conjugate known from T. versicolor. The conjugates showed a distinctly lower cytotoxic and microbicidal activity than triclosan did.Triclosan (2,4,4Ј-trichloro-2Ј-hydroxydiphenyl ether; synonym, Irgasan DP 300) has been used as an antimicrobial compound in deodorants (6), soaps, and dentifrices (2, 8, 36) for many years. The mode of action of triclosan has, however, remained unclear. Recently, it was shown that triclosan blocks one step in bacterial fatty acid synthesis (20,24,25). Due to its widespread use, triclosan and some of its derivatives can be detected in the environment (22,26,27). The chemical structure of triclosan is related to many compounds which are wellknown as xenobiotics, such as halogenated diphenyl ethers. Though some reports on the transformation of halogenated diphenyl ether compounds by bacteria are available (21, 30), triclosan itself was not metabolized by the strains tested (31) or by Rhodococcus chlorophenolicus, which can methylate several other chlorinated hydroxydiphenyl ethers (34). Several hydroxylated metabolites, as well as 2,4-dichlorophenol and 4-chlorocatechol, are formed from triclosan by rats (33), while guinea pigs mostly form glucuronide conjugates (3). No reports exist concerning the degradation of triclosan by fungi. The white rot fungi Trametes versicolor and Pycnoporus cinnabarinus are capable of transforming diphenyl ethers, like 4-chlorodiphenyl ether, up to ring cleavage (10, 11). Hydroxylated biarylic ethers are transformed to oligomerization products by laccases secreted by these strains (13). In this paper we describe some biotransformation reactions of triclosan by the white rot fungi T. versicolor and P. cinnabarinus.The strains T. versicolor SBUG-M 1050, T. versicolor DSM 11269, T. versicolor DSM 11309, and P. cinnabarinus SBUG-M 1044 were cultivated in a nitrogen-rich (8 mM) medium. The cultures for transformation were prepared with 0.25 mM (wt/ vol) triclosan (Mallinckrodt-Baker, Griesheim, Germany) and inoculated and incubated as described previously (10, 11).Cell extracts were prepared from a 3-day culture of T. versicolor, harvested by centrifugation, and washed twice with 50 mM ice-cold Tris-HCl buffer (pH 7.5). Cells were broken at 1,000 lb/in 2 using a French press (SLM Amnico, Rochester, N.Y.) and were immediately resuspended in Tris-HCl buffer. The cell extracts (4 ml, approximately 5 mg of protein ml Ϫ1 ) were incubated at 30°C for 24 h with 2.88 mg of triclosan and 1 mg each of UDP-xylose, UDP-glucose, and UDP-glucuronic acid (Sigma, Deisenhofen, Germany).Analysis of metabolites in culture supernatants and purification of intermediates were done by high-performance liquid ...

Thirty milk samples [high-temperature short-time (HTST) milk, extended shelf life (ESL) milk (directly heated, indirectly heated, microfiltered), ultra-high temperature milk] from 17 German dairies were analysed. Total viable counts of directly or indirectly heated ESL milk were significantly lower than those in microfiltered ESL and HTST milk. Evaluation of indigenous enzyme activity revealed sufficient heat treatments in all milk samples. The manufacturing processes were differentiated by estimating furosine and acid soluble whey proteins. Sensory examinations revealed a preference for HTST heated and microfiltered ESL milk. However, a significant discrimination of drinking milk types was not possible. Vitamin losses were not detected, and concentrations of vitamins in different types of milk were comparable.Keywords Drinking milk, Microbiological status, Head load evaluation, Sensory quality, Vitamin status. I N T R O D U C T I O NExtended shelf life (ESL) milk has a shelf life of about 3 weeks under chill chain conditions and fills the gap between high-temperature short-time (HTST)-heated milk, which typically is assigned a shelf life of 10 days and ultra-high temperature (UHT)-heated milk, which can be stored for a few months without cooling (Hoffmann et al. 2006). In Germany, ESL milk has a market share of 20-25%. For comparison, UHT milk has a share of approximately 70%, and HTST milk has a market share of 5-10% (BLE 2008). The term ESL milk as well as the manufacturing process is not legally defined in the European Union. A thermal treatment or combination of heat treatment and membrane filtration are involved in the production of ESL milk. The thermal process requires direct or indirect heating at 123-127°C with a holding time of 1-5 s. Traditional HTST pasteurisation is carried out at 72-75°C for 15-30 s, and UHT milk is heated at a minimum of 135°C for a few seconds (sterilisation value F 0 ‡ 3 min) (Schwermann and Schwenzow 2008a,b;Kaufmann et al. 2009). The combined treatment process for ESL milk includes microfiltration of skim milk through ceramic membranes with an average pore diameter of 0.8-1.4 lm. As a result, a spore reduction of 3-5 log 10 steps is achieved and most other forms of microorganisms are also separated. The so enriched retentate and a specific amount of cream are heated at 123-127°C, homogenised, and mixed with the HTST heated skim milk permeate (Hoffmann et al. 2006;Schwermann and Schwenzow 2008c;Henke 2009).Microbial spoilage of heat treated drinking milk is caused by heat-resistant or recontaminating micro-organisms. The former group is represented by spore forming micro-organisms, mainly Bacillus spp. and Enterococci. The latter group consists of Gram-positive nonspore forming bacteria and Gram-negative bacteria. These organisms gain significance if they are psychrophilic or psychrotrophic and able to multiply at refrigeration temperatures (Blake et al. 1995;Mayr et al. 2004;Kress et al. 2005;Kaufmann and Kulozik 2008).Several parameters are suited for the evaluation of milk...

Physicochemical and antibacterial properties of native and modified whey proteins at pH 2 to 7 Highlights • Whey protein isolate was covalently modified with allyl isothiocyanate • The adducts showed increased hydrophobicity at pH 2, 4 and 6 • The protein β-sheet content increased • Interfacial tension was reduced • Antimicrobial activity of WPI was not significantly influenced

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Summary To apply native casein micelles (CM) as nanocarriers for lipophilic substances in non‐ or low‐fat food products, they have to be conditioned before loading. In this study, an experimental set‐up for the production and loading of CM was developed. Microfiltration was used to separate CM from skimmed milk. To identify optimal loading conditions temperatures (2, 20, 40 °C), pH values (6.8 and 5.5) and holding times (5, 15, 30, 60 min) were varied. The release of calcium, phosphate and protein from the micellar phase as well as static light scattering and transmission electron microscopy showed that CM were optimally primed at 2 °C and a pH of 5.5 for 5 min. Therefore, loading with β‐carotene was performed under those conditions. After the back‐extraction of β‐carotene, the photometrical analyses revealed total recovery rates of >79% whereby 94% of it was associated with the native CM.

The in vitro modulation of apoptosis and cell proliferation by modified in comparison with non-modified ribonucleosides was investigated for the first time using peripheral blood lymphoeytes, HL-60 cells and Caco-2 cells as human cell culture models. Modulating effects of several ribonucleosides were found in the range of 10-~-10 s mol/i. The following ribonuclensides induced significant apoptosis of HL-60 cells: adenosine, N6-dimethyladenosine, N~-(2-isopentenyl)-adenosine, N2-dimethylguanosine. A significant apoptotic effect on PBL was found with N6-dimethyladenosine and N°-(2 -isopentenyl)-adenosine. N6-Dimethyladenosine, N6-(2-isopentenyl)-adenosine and guanosine had a pronounced inhibitory effect on Caco-2 cell apoptosis. Regarding the known function of ribonucleosides as pathobiochemical marker molecules for cancer, the possibility of a selective apoptotic effect against malignant cells is discussed.