Laboratory of the Government Chemist

London, United Kingdom

Laboratory of the Government Chemist

London, United Kingdom
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Johnson P.E.,UK Institute of Food Research | Baumgartner S.,University of Natural Resources and Life Sciences, Vienna | Aldick T.,UK Institute of Food Research | Bessant C.,Cranfield University | And 11 more authors.
Journal of AOAC International | Year: 2011

Allergen detection and quantification is an essential part of allergen management as practiced by food manufacturers. Recently, protein MS methods (in particular, multiple reaction monitoring experiments) have begun to be adopted by the allergen detection community to provide an alternative technique to ELISA and PCR methods. MS analysis of proteins in foods provides additional challenges to the analyst, both in terms of experimental design and methodology: (1) choice of analyte, including multiplexing to simultaneously detect several biologically relevant molecules able to trigger allergic reactions; (2) choice of processing stable peptide markers for different target analytes that should be placed in publicly available databases; (3) markers allowing quantification (e.g., through standard addition or isotopically labeled peptide standards); (4) optimization of protease digestion protocols to ensure reproducible and robust method development; and (5) effective validation of methods and harmonization of results through the use of naturally incurred reference materials spanning several types of food matrix. © 2012 Publishing Technology.

Tolan A.,Ministry of Agriculture, Fisheries and Food | Robertson J.,Ministry of Agriculture, Fisheries and Food | Orton C.R.,Ministry of Agriculture, Fisheries and Food | Head M.J.,Wood Manor | And 2 more authors.
British Journal of Nutrition | Year: 2011

1. The nutrient content of battery, deep litter and free range eggs from domestic hens under systems of management typical of those used in the commercial production of eggs was studied from January to March 1968. 2. Monthly samples of eighteen eggs, supplied by six centres, were homogenized, freezedried, ground and stored at −15°. Their contents of moisture, nitrogen, amino acids, fats, fatty acids and cholesterol, ash, sodium, potassium, calcium and iron, thiamin, riboflavin, nicotinic acid, pantothenic acid, folic acid, vitamin B12, tocopherols and retinol were determined. The mean values for eggs from each system, each centre and each quarter of the year were calculated. 3. For many nutrients, no significant difference between systems was detected; the greatest variations occurred in the content of some vitamins. Free range eggs contained more vitamin B12 than deep litter or battery eggs and more folic acid (Lactobacillus casei assay) than battery eggs. Differences in tocopherol and cholesterol contents were complicated by system-by-centre interactions. There were also small differences in calcium and iron contents. 4. Riboflavin, folic acid (Lactobacillus casei) and vitamin B12 were the only nutrients which were observed to vary with the time of year in the eggs from all systems of management. Major differences were found in the vitamin content of eggs from different centres. 5. Though the differences in vitamin B12 and folic acid contents which result from the different systems of management are of little significance in an average mixed diet, they would be measurable for some individuals who may depend on eggs as an important source of these nutrients. © 1974, The Nutrition Society. All rights reserved.

Morton V.L.,University of Leeds | Burkitt W.,Laboratory of the Government Chemist | O'Connor G.,Laboratory of the Government Chemist | Stonehouse N.J.,University of Leeds | And 2 more authors.
Physical Chemistry Chemical Physics | Year: 2010

A detailed knowledge of the capsid assembly pathways of viruses from their coat protein building blocks is required to devise novel therapeutic strategies to inhibit such assembly. In the quest for understanding how assembly of single-stranded RNA viruses is achieved at the molecular level, HDX-MS has been used to locate regions of a coat protein dimer that exhibit conformational/ dynamical changes, and hence changes in their HDX kinetics, upon binding to a genomic RNA stem-loop known to trigger assembly initiation. The HDX-MS data highlight specific areas within the coat protein dimer that alter their exchange kinetics in the presence of the RNA. These include the known RNA-binding sites, β-strands E and G, which have a lower susceptibility to HDX when ligand-bound, as may have been expected. In contrast, several exposed regions are unaffected by ligand binding. Significantly in this example, the loop between β-strands F and G exhibits reduced HDX propensity when the RNA is bound, consistent with previous inferences from NMR and normal mode analysis that suggested a local conformational change at this loop induced by dynamic allostery. These results demonstrate the potential utility of HDX to probe conformational and dynamical changes within non-covalently bound protein-ligand complexes which are of widespread importance in many biomolecular systems. © 2010 the Owner Societies.

PubMed | Laboratory of the Government Chemist
Type: Journal Article | Journal: Meat science | Year: 2011

The 4-hydroxy-l-proline content of a variety of meats and meat products was determined both by carbon-13 pulsed Fourier transform nuclear magnetic resonance (FTNMR) spectroscopy and by a traditional colorimetric method. These two fundamentally different methods gave results which were in good agreement; both methods require chemically free 4-hydroxy-l-proline from hydrolysis which is the time-consuming experimental step. The relative merits are discussed with reference to specifity, operator time and sample throughput. Observation of 4-hydroxy-l-proline without time-consuming hydrolysis by (13)C-FTNMR spectroscopy was found to be possible with collagen and with carbohydrate-free meat samples. Direct observation without such hydrolysis could be useful as a rapid survey method if carbohydrate interferences can be eliminated.

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