The use of metabonomic profiling approaches for the investigation of complex food fraud

Food fraud is a challenge in today's expanding global food industry. Recently weaknesses in current testing methods for meat authentication have been exposed. Labels are assumed to accurately describe the contents of meat products, however these can be easily manipulated. Consumers must have confidence in food products for various reasons, including allergies and religious beliefs. Techniques have been created to target obvious types of fraud, however the more subtle types remain difficult to combat. This work aimed to understand the chemical composition of meat products in order to develop methods that can tackle complex frauds. The development of a data processing and statistical workflow sufficient for vast untargeted metabonomic datasets was also essential for this research. Liquid chromatography quadrupole time-of-flight mass spectrometry, with robust quality control procedures and multivariate statistics, were used to measure changes in the metabolic profile of meat samples. Specifically, the differentiation between normally slaughtered and dead on arrival chicken was achieved, and sphingosine was identified as a key marker in the muscle tissue. An investigation into the duration of frozen storage and freeze-thaw cycling of meat found the fatty acid degradation pathways were most affected. The adulteration of minced beef products with other meat species yielded the tentative identifications of several markers that could be used to detect adulterated beef products regardless of whether the meat is raw or cooked. Finally, the metabolic changes occuring during the spoilage of chicken were observed, and showed that amino acid and fatty acid concentration could be used to determine the shelf-life of meat products. The methodologies that have been presented in this work have shown potential to be implemented and developed as robust detection methods to combat subtle food frauds in the future

The use of metabonomics to uncover differences between the small molecule profiles of eggs from cage and barn housing systems

Metabonomic techniques have been used to observe differences in the small molecule profiles of chicken eggs, to work towards the detection, and thus prevention, of fraud regarding the misrepresentation of egg farming systems. High Performance Liquid Chromatography-Quadrupole-Time-of-Flight-Mass Spectrometry (HPLC-Q-ToF-MS) was used to obtain profiles of the small molecules found in the yolks of eggs that were laid by hens in enriched cage systems, and in barn systems. Statistical analysis of these small molecule profiles, including the use of XCMS Online and multivariate statistics, was able to uncover differences between the yolks of cage and barn eggs. Several unidentified compounds were found to be present in significantly different abundances between cage and barn egg yolks and one of these compounds was tentatively identified, through the use of METLIN, as 1,2-dipalmitoyl-glycero-3-phosphocholine

Metabonomic profiling of chicken eggs during storage using high-performance liquid chromatography–quadrupole time-of-flight mass spectrometry

Metabonomic techniques have been used to discover subtle differences in the small-molecule profiles of chicken eggs, which could help to combat fraud within the egg industry. High-performance liquid chromatography–quadrupole time-of-flight mass spectrometry (HPLC-Q-ToF-MS) was used to obtain profiles of the small molecules present in the yolks of chicken eggs stored for different lengths of time. Statistical analysis, including the use of XCMS Online and further exploratory statistics, was able to uncover differences in the abundances of several of the small molecules found in these egg yolks. One of these small molecules was identified through the use of METLIN and MS/MS analysis as choline. A targeted study was then carried out over a longer storage period, using the same instrumentation and analytical techniques, in order to observe how the concentration of choline in egg yolk changes over a longer period of time

The Use of Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry and Metabonomic Profiling to Differentiate Between Normally Slaughtered and Dead On Arrival Poultry Meat

Metabonomic profiling techniques, with established quality control methods, have been used to detect subtle metabolic differences in tissue that could aid in the discovery of fraud within the food industry. Liquid chromatography quadrupole time-of-flight mass spectrometry (LC-Q-TOF-MS) was utilized to acquire metabolic profiles of muscle, heart, and liver tissue from normally slaughtered and dead on arrival chickens. A workflow including XCMS Online for data processing and robust confirmatory statistics was used in order to differentiate between the two sample types. It was found that normally slaughtered and dead on arrival chicken can be differentiated based on the metabolic profile and multivariate analysis. Markers were found to be significantly different between the two sample types in all samples. With the use of the METLIN database and MS/MS analysis of chemical standards, sphingosine was identified as a marker in the muscle tissue samples which may offer potential for the detection of fraudulently processed chicken meat. The approach taken in this work has shown that it is possible to apply the described workflows to food fraud problems, with an objective of identifying key markers that could be investigated further to determine their usefulness for fraud detection

The effect of storage temperature on the metabolic profiles derived from chicken eggs

Metabonomic profiling, using High Performance Liquid Chromatography Quadrupole Time-of-Flight Mass Spectrometry (HPLC-Q-ToF-MS), was adopted in this study to uncover differences in the small molecule profiles of egg yolks, between two sets of six eggs that were stored at 5 °C and 23 °C for five weeks. Choline, a compound that has previously been shown to have potential use as a biomarker of egg age, was observed to have a significantly lower abundance in the yolks of eggs that were stored at 5 °C for five weeks compared to eggs stored at 23 °C for the same length of time. A follow-up targeted study observed that the previously discovered trend of increasing choline concentration in egg yolk, with increasing egg age, is not repeatable when the eggs are stored at 5 °C rather than 23 °C. It concluded that, by refrigerating eggs at 5 °C, the accurate prediction of egg age using choline as a biomarker can be prevented

Screenings and grit in sewage Removal, treatment and disposal; preliminary report

Incl. folded diagramSIGLEAvailable from British Library Lending Division - LD:8673.78(CIRIA-TN--119) / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Screenings and grit in sewage; removal, treatment and disposal Phase 2; further cost aspects of screening practice

25.00Available from British Library Document Supply Centre- DSC:8673.78(CIRIA-TN--122) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo