Perennial ryegrass (Lolium perenne) is integral to temperate pastoral agriculture, which contributes most of the milk and meat production worldwide. Chemical profiles and diversity of ryegrass offer several opportunities to harness specific traits and elucidate underlying biological mechanisms for forage improvement. We conducted a large-scale metabolomics study of perennial ryegrass comprising 715 genotypes, representing 118 populations from 21 countries. Liquid/gas chromatography–mass spectrometry based targeted and non-targeted techniques were used to analyse fructan oligosaccharides, lipids, fatty acid methyl esters, polar and semi-polar compounds. Fructan diversity across all genotypes was evaluated, high- and low-sugar groups identified, and fructan accumulation mechanisms explored. Metabolites differentiating the two groups were characterised, modules and pathways they represent deduced, and finally, visualisation and interpretation provided in a biological context. We also demonstrate a workflow for large-scale metabolomics studies from raw data through to statistical and pathway analysis. Raw files and metadata are available at the MetaboLights database.

Holistic benefits of human milk to infants, particularly brain development and cognitive behavior, have stipulated that infant formula be tailored in composition like human milk. However, the composition of human milk, especially lipids, and their effects on brain development is complex and not fully elucidated. We evaluated brain lipidome profiles in weanling rats fed human milk or infant formula using non-targeted UHPLC-MS techniques. We also compared the lipid composition of human milk and infant formula using conventional GC-FID and HPLC-ELSD techniques. The sphingomyelin class of lipids was significantly higher in brains of rats fed human milk. Lipid species mainly comprising saturated or mono-unsaturated C18 fatty acids contributed significantly higher percentages to their respective classes in human milk compared to infant formula fed samples. In contrast, PUFAs contributed significantly higher percentages in brains of formula fed samples. Differences between human milk and formula lipids included minor fatty acids such as C8:0 and C12:0, which were higher in formula, and C16:1 and C18:1 n11, which were higher in human milk. Formula also contained higher levels of low- to medium-carbon triacylglycerols, whereas human milk had higher levels of high-carbon triacylglycerols. All phospholipid classes, and ceramides, were higher in formula. We show that brain lipid composition differs in weanling rats fed human milk or infant formula, but dietary lipid compositions do not necessarily manifest in the brain lipidome.

Rationale: The aroma profile of food is a complex mixture of volatile compounds that constitutes a major component of the overall eating experience. The food service industry and chefs therefore constantly seek ways to investigate and thereby enhance the aroma profile. Oven cooking, sous vide and pan fry are three cooking methods of beef commonly practised by chefs. Near real‐time analysis of volatile compounds from these three cooking methods will provide insight into respective volatile fingerprints and help improve cooking techniques. Methods: Volatile compounds from three beef cooking methods were captured using an in‐house sol–gel based solid phase microextraction (SPME) method and analysed using direct analysis in real‐time mass spectrometry (DART‐MS). A volatile organic compound (VOC) standard was used to demonstrate successful implementation of the sol–gel coating technique. Volatile features discriminating the three cooking methods were shortlisted and statistically assessed by univariate and multivariate analyses. Results: The VOC standard was successfully adsorbed by the sol–gel method and detected by DART‐MS. Hierarchical cluster analysis clearly demarcated three beef cooking methods based on their volatile fingerprints. Out of 65 significant features differentiating the cooking methods, 50 were at highest concentrations from pan‐fry cooking only, followed by 14 with highest concentrations from oven cooking followed by pan frying. Sous vide followed by pan frying showed lowest concentrations of almost all volatile features. Conclusions: The sol–gel‐based solid‐phase microextraction technique combined with DART‐MS was successful in differentiating beef cooking methods based on their volatile fingerprints. A workflow for rapid assessment of the volatile profile from beef cooking methods was established, providing a baseline to further explore volatile profiles from other key ingredients.

The increasing diversity of potential biosecurity threats makes their diagnosis a complicated and evolving area, requiring moving beyond traditional taxonomic species identification. New biosecurity diagnostic tools should provide a greater depth of information on threat biology to enable accurate risk assessment for the more efficient and effective deployment of biosecurity resources. Metabolomics is amongst the new approaches being explored for biosecurity diagnostics, where a broad spectrum of metabolites might signify relevant biological characteristics of an intercepted organism. Examples of these characteristics are physiological signatures of age, reproductive status, geographic origin, pathogen status of potential invertebrate vectors, and the distinction between diseases and abiotic plant stress symptoms. This broad-based approach is attractive, where several biological characteristics of an organism can be assessed with a single measurement. However, it can be impractical as several hundred biological replicates of the organism are needed to build a robust model of a species. New approaches such as mass spectral fingerprinting substantially reduce the time taken for metabolomics measurements, and more sophisticated modelling methods aid feasibility. Promising data are emerging for metabolomics and metabolite fingerprinting for potential biosecurity applications. We discuss the possibilities and potential uses for these new tools for post-detection decisions, diagnosis, and biosecurity.