Reaction kinetics of the heat-induced formation of N6-methyladenosine in milk

Schlimme, E.; Ott, F. G.; Kiesner, Christian

doi:10.1016/0958-6946(94)90037-x

Cited by 9 publications

(4 citation statements)

References 8 publications

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“…The pattern of ribonucleosides in mature milk varies only slightly throughout lactation. From experimental findings concerning changes in the contents of ribonucleosides in heat-treated milk Schlimme et al 1993Schlimme et al , 1994Schlimme et al , 1998Martin et al 1995Martin et al , 1997Martin et al , 1998 it can be concluded that the concentrations of cytidine, guanosine and inosine present in raw milk show a multifold increase in milk which has been subjected to thermization and holder pasteurization, whereas the adenosine level decreases. On the other hand, these enzyme-(e.g.…”

Section: Technochemical Aspectsmentioning

confidence: 99%

“…m6Ado, which is not detectable under the pH and temperature conditions prevailing in thermally untreated milk , is formed by a Dimrothrearrangement from m1Ado as a function of heating time and temperature Schlimme et al 1993Schlimme et al , 1994Martin et al 1995). This rearrangement follows first order kinetics in the temperature range between 1158C and 1508C with a z-value of 26´88C and a Q 10 -value of 2´36 (Schlimme et al 1994;Martin et al 1997). The kinetic data found for this rearrangement agree quite well with those found for other thermally induced chemical reactions in milk, e.g.…”

Section: Technochemical Aspectsmentioning

confidence: 99%

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Nucleosides and nucleotides: natural bioactive substances in milk and colostrum

2000

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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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Section: Technochemical Aspectsmentioning

confidence: 99%

Section: Technochemical Aspectsmentioning

confidence: 99%

Nucleosides and nucleotides: natural bioactive substances in milk and colostrum

2000

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“…Ribonucleotide concentrations decrease while those of ribonucleosides and purine bases increase with the sterilization temperature [93]. Milk heat treatment causes changes in the contents of the unmodified ribonucleosides Ado, Cyd, Guo, Ino and Urd [94], as well as in the contents of the modified ribonucleosides m1Ado, m6Ado and t6Ado [94][95][96][97]. From the viewpoint of dairy technology, ribonucleosides represent minor milk constituents that are useful as chemical indicators for characterizing technological treatment [94,[98][99][100][101][102], and quantifying adulterations of milk and milk products [103][104][105].…”

Section: Ribonucleosides As Components Of Foodmentioning

confidence: 99%

Nucleoprotein-Derived and Unbound Ribonucleosides: Bioactivity and Potential Applications

Martin¹,

Meisel²

2007

CPD

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Naturally occurring and chemically modified ribonucleosides have interesting bioactive effects. Dietary ribonucleosides are ingested mainly as nucleoproteins and are converted in the course of intestinal digestion to monomeric compounds. Different bioactive effects of dietary ribonucleosides have been described, including the ability to enhance gut growth and maturation and to increase iron absorption. Cytochemical studies with human cells showed that several ribonucleosides can induce apoptosis in human cells, and therefore may be potentially anticancerogenic compounds. Even if suboptimal concentrations of single bioactive nucleo compounds are available from food, the total content of different bioactive ribonucleosides may reach physiologically effective concentrations in vivo where intestinal cells may represent the main target sites of a selective apoptotic activity. Modified ribonucleosides serve as valuable pathobiochemical marker molecules for cancer. Chemically modified ribonucleosides have already found interesting applications as pharmaceutically active compounds in the treatment of different illnesses including AIDS. Regarding therapeutic and pharmaceutical aspects, further studies are required to evaluate the bioactive efficacy of indigenous ribonucleosides. The findings demonstrate the great variety of potential applications of ribonucleosides, e.g. in functional foods as well as pharmaceutical preparations.

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“…Some quality indicators that have been investigated for UHT processes are: colour changes in milk; 2 hydroxymethylfurfural (HMF); 3 thiamine; 5 available lysine; 6 lactulose; 7–9 epilactose; 4 furosine; 10 N6, methyl adenosine 11,12 and the formation of compounds such as N‐ɛ‐carboxymethyllysine (CML) 10 . Others include the Aschaffenburg turbidity test and enzyme inactivation.…”

Section: Introductionmentioning

confidence: 99%

Predicting safety and quality parameters for UHT‐processed milks

Browning

Lewis

MacDougall

2001

Int J of Dairy Tech

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A spreadsheet was developed to evaluate safety and quality parameters for milks subjected to different heating and cooling profiles and holding time conditions in a continuous heat exchanger. Safety parameters evaluated were lethality ( Fo ) and microbial inactivation ( B *) values; quality parameters were chemical change ( C *), thiamin loss, lactulose formation, Maillard browning and hydroxymethylfurfural (HMF) formation. The spreadsheet was used to predict these parameters for a pilot plant, heating milks at 120-150 ° C for 4, 27 and 58 s, using its heating and cooling profiles. Milks were processed in the same plant at these conditions and a selection of the milks were analysed to establish the validity of the spreadsheet. All samples with a C * value < 3 gave a positive Aschaffenburg turbidity. The activation energy that gave the best agreement between the predicted and experimental results for lactulose was found to be 122 kJ/mol. One set of optimized conditions for this product was 135 ° C for 10 s, giving B * = 1.24 and C * = 0.55. This milk was compared with two others and its sensory characteristics were similar to that with a C * of 1.5 but different to that with a C * value of 6. Browning was only found to be noticeable in the most severely heat-treated sample immediately after processing, but would become apparent on storage at 30 ° C and above. The spreadsheet is useful for comparing the characteristics of products from plants with different heating profiles or as a means for optimizing UHT plant performance where the heating and cooling rates are fixed.

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Reaction kinetics of the heat-induced formation of N6-methyladenosine in milk

Cited by 9 publications

References 8 publications

Nucleosides and nucleotides: natural bioactive substances in milk and colostrum

Nucleosides and nucleotides: natural bioactive substances in milk and colostrum

Nucleoprotein-Derived and Unbound Ribonucleosides: Bioactivity and Potential Applications

Predicting safety and quality parameters for UHT‐processed milks

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