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Ridgway K.,Reading Scientific Services Ltd
Food Engineering and Ingredients | Year: 2010

The presence of compounds causing taints and offflavours in food is a major concern to the food industry. However, the identification of these chemicals in foods presents an analytical challenge due to the complexity of the matrix, the need for sensitive methodologies and the commercial pressure for rapid results. Source

Ruxton C.H.,Nutrition Communications | Hart V.A.,Reading Scientific Services Ltd
British Journal of Nutrition | Year: 2011

There is a belief that caffeinated drinks, such as tea, may adversely affect hydration. This was investigated in a randomised controlled trial. Healthy resting males (n 21) were recruited from the general population. Following 24 h of abstention from caffeine, alcohol and vigorous physical activity, including a 10 h overnight fast, all men underwent four separate test days in a counter-balanced order with a 5 d washout in between. The test beverages, provided at regular intervals, were 4 Ã-240 ml black (i.e. regular) tea and 6 Ã-240 ml black tea, providing 168 or 252 mg of caffeine. The controls were identical amounts of boiled water. The tea was prepared in a standardised way from tea bags and included 20 ml of semi-skimmed milk. All food taken during the 12 h intervention period was controlled, and subjects remained at rest. No other beverages were offered. Blood was sampled at 0, 1, 2, 4, 8 and 12 h, and a 24 h urine sample was collected. Outcome variables were whole blood cell count, Na, K, bicarbonate, total protein, urea, creatinine and osmolality for blood; and total volume, colour, Na, K, creatinine and osmolality for urine. Although data for all twenty-one participants were included in the analysis (mean age 36 years and mean BMI 25•8 kg/m 2), nineteen men completed all conditions. Statistical analysis, using a factorial ANOVA approach within PROC MIXED, revealed no significant differences between tea and water for any of the mean blood or urine measurements. It was concluded that black tea, in the amounts studied, offered similar hydrating properties to water. © 2011 The Authors. Source

Jawad R.,Kings College London | Drake A.F.,Kings College London | Elleman C.,Reading Scientific Services Ltd | Martin G.P.,Kings College London | And 5 more authors.
Molecular Pharmaceutics | Year: 2014

This article reports on the stereochemical aspects of the chemical stability of lactose solutions stored between 25 and 60 °C. The lactose used for the preparation of the aqueous solutions was α-lactose monohydrate with an anomer purity of 96% α and 4% β based on the supplied certificate of analysis (using a GC analytical protocol), which was further confirmed here by nuclear magnetic resonance (NMR) analysis. Aliquots of lactose solutions were collected at different time points after the solutions were prepared and freeze-dried to remove water and halt epimerization for subsequent analysis by NMR. Epimerization was also monitored by polarimetry and infrared spectroscopy using a specially adapted Fourier transform infrared attenuated total reflectance (FTIR-ATR) method. Hydrolysis was analyzed by ion chromatography. The three different analytical approaches unambiguously showed that the epimerization of lactose in aqueous solution follows first order reversible kinetics between 25 to 60 °C. The overall rate constant was 4.4 × 10-4 s-1 ± 0.9 (± standard deviation (SD)) at 25 °C. The forward rate constant was 1.6 times greater than the reverse rate constant, leading to an equilibrium constant of 1.6 ± 0.1 (±SD) at 25 °C. The rate of epimerization for lactose increased with temperature and an Arrhenius plot yielded an activation energy of +52.3 kJ/mol supporting the hypothesis that the mechanism of lactose epimerization involves the formation of extremely short-lived intermediate structures. The main mechanism affecting lactose stability is epimerization, as no permanent hydrolysis or chemical degradation was observed. When preparing aqueous solutions of lactose, immediate storage in an ice bath at 0 °C will allow approximately 3 min (180 s) of analysis time before the anomeric ratio alters significantly (greater than 1%) from the solid state composition of the starting material. In contrast a controlled anomeric composition (∼38% α and ∼62% β) will be achieved if an aqueous solution is left to equilibrate for over 4 h at 25 °C, while increasing the temperature up to 60 °C rapidly reduces the required equilibration time. © 2014 American Chemical Society. Source

Jawad R.,Kings College London | Elleman C.,Reading Scientific Services Ltd | Vermeer L.,Kings College London | Drake A.F.,Kings College London | And 3 more authors.
Pharmaceutical Research | Year: 2012

Purpose: Reports of the anomeric composition of amorphous lactose are rare and state a highly variable range of composition (between 0% and 60% w/w β content).We aimed to develop a quantitative measurement by 1H-NMR of α and β anomer content in amorphous lactose produced by different production methods. Methods: Amorphous lactose was prepared by spray and freeze drying 10% w/v aqueous solutions of lactose. NMR analysis was performed in DMSO; peak areas of partially resolved doublets at 6.3 and 6.6 ppm were used to calculate % of α and β lactose present. Polarimetery was used to determine optical rotation of lactose solutions. Results: Observed specific rotation for supplied crystalline alpha lactose monohydrate of 88° recorded in DMSO was constant for the length of a typical NMR experiment (max. 10 min). β/αanomer contents of amorphous lactose measured by 1H-NMR had standard deviations as low as 0.1% w/w (n=6). Drying a lactose solution 4 h after its preparation led to almost 35% w/w difference in anomer composition within solid amorphous material compared to samples dried after only 30 min, e.g. for freeze dried samples, β content was 60±0.1% w/w (4 h) and 25±1.0% w/w (30 min). Mutarotation leads to this increase in β anomer concentration in aqueous solution and within the solid amorphous lactose stored at 25° C e.g. after 56 d storage the βcontent of freeze dried lactose (30 min solution) increased from 25±1.0% to 50±0.5% w/w. Conclusion: A simple solution-based 1H-NMR method for measurement of anomeric composition of lactose has been established. The solution β/α ratio at the time of drying is mirrored in the composition of the resulting solid amorphous material. In order to produce a consistent anomer composition within spray and freeze dried amorphous lactose, the standing time for the feed solution should be greater than 4 h, such that the most dynamic region of the mutarotation profile has been exceeded. If the amorphous material has been formed from a solution that has not been allowed to equilibrate for 4 h, the resulting solid will continue to undergo mutarotation if trace amounts of moisture are present, until the anomeric β/α ratio slowly approaches 1.7. © Springer Science+Business Media, LLC 2011. Source

Payne G.,Reading Scientific Services Ltd | Lad M.,Riddet Institute | Foster T.,University of Nottingham | Khosla A.,University of Nottingham | Gray D.,University of Nottingham
Colloids and Surfaces B: Biointerfaces | Year: 2014

Neutral-lipids within oilseeds are most commonly stored in oil bodies, small spherical organelles with oleosin proteins inserted through a phospholipid monolayer. Oil bodies extracted from Echium plantagineum are highly enriched in polyunsaturated fatty acids and are stable to coalescence and oxidation. This stability has been attributed to the strong association between the phospholipid monolayer and oleosin proteins. To better understand this association the phospholipid fatty acyl groups of E. Plantagineum oil bodies were determined for the first time; a large proportion (≈70%) of saturated fatty acids were present, and this may aid in oleosin anchorage and thus contributes to oil body stability. The effect of oil body washing on surface charge was also observed (using turbidity, zeta and streaming potentials), and dependent on the washing protocol, E. Plantagineum oil bodies had an isoelectric point of pH 4-5. This is significantly different to pI values for oil bodies from a range of other seeds reported in the literature using isoelectric focusing; a possible explanation for this discrepancy is discussed. © 2014. Source

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