1,720,991 research outputs found
Using metabolomics to describe food in detail
No full textFood science has been increasingly linked to other fields such as medicine, veterinary science, agriculture, biology, and genetics. Metabolomics can assist those different fields by identifying connections between food quality and health, while accounting for food quality changes that result from human and environmental perturbations on the food metabolome. This chapter summarises some methods for applying metabolomics in the evaluation of food quality as it relates to genetic selection and modifications, different growing (e.g. organic vs. conventional) and rearing conditions, geographic origin, food manufacturing protocols, and the effect of digestion on the nutrient availability
Approccio metabolomico per la valutazione della digeribilità di un idrolizzato di caseina con proprietà anti-ipertensive.
No full textA 1H NMR-Based Metabolomics Approach on Dietary Biomarker Research in Human Urine
No full textThe analysis of the metabolome has become particularly important in human studies, allowing the identification of typical and atypical metabolites in determined biofluids and tissues. This is clearly fundamental for medical investigations, since it could be possible to assess the presence or absence of certain diseases and syndromes or risk conditions. Another widespread use of the metabolomic approach is the research on specific dietary effects on the metabolic profile. It is necessary to take research further and investigate the presence of determined food molecules in fluids or tissues from individuals without a controlled dietary intervention. NMR spectroscopy techniques can be very useful in different nutrimetabonomics approaches, thanks to the quickness, high-throughput efficacy and high-reproducibility of its methods. In this paper the two main nutrimetabolomic strategies were highlighted, both greatly aided by the use of NMR spectroscopy. The first one requires a direct intervention on a sample population in order to assess the direct effects on the metabolome after the intake of a particular food product or category. In the other technique, instead, observational studies in free-eating populations are carried out. At first nutritional data is analysed in order to find possible dietary patterns, then these have to be proved by the inspection of biofluid spectra, in order to find molecules capable in discriminating among the dietary behaviours
A "Foodomic" Approach for the Evaluation of Food Quality and its Impact on the Human Metabolome
Full text linkIn recent years, omic sciences have been increasingly employed in many research fields thanks to their high-throughput capabilities and holistic approach.
Among the omics sciences, metabolomics and foodomics have recently emerged for the investigation of food and nutrition and their relation to the individual health and wellness status.
The analytical platforms used are ideal for non-targeted analysis, due to their capability of detecting and identifying a large set of variables (or metabolites) in complex biological samples. The most employed metabolomics techniques are mass spectrometry and nuclear magnetic resonance spectroscopy, empowered by the advent and advancement of multivariate data analysis.
This thesis outlines the analytical pipeline of the foodomic approach and highlights the current challenges in the field, tracing the path of modern foodomics from the definition and description of food quality to the profiling of the human metabolome, and the investigation of the impact of food on human health, the prevention of diseases and the identification of biomarkers of health status.
The impact of factors such as genetic modification or farming method was investigated in plant-based foods. And the effect of the food matrix and digestion on the stability and bioaccessibility of specific molecules was assessed.
The animal metabolome was also studied, for example investigating the effect of antibiotic treatment on necrotizing enterocolitis as a model for the treatment of this condition in human newborns, too.
The human metabolome (plasma, serum, urine) was then explored, firstly to develop specific algorithms for the search of dietary biomarkers in observational studies. Moreover, food intake biomarkers have been discovered in an intervention study (i.e. galactose for milk intake) and will be further investigated. Research was also carried out to investigate on specific disease-related biomarkers and to discover possible trajectories from a disease state to a healthier condition
1H NMR foodomics reveals that the biodynamic and the organic cultivation managements produce different grape berries (Vitis vinifera L. cv. Sangiovese)
Full text linkThe increasing demand for natural foods and beverages, i.e. prepared by excluding synthetic chemicals along the whole production chain, has boosted the adoption of organic and biodynamic cultivation methods which are based on protocols avoiding use of synthetic pesticides. This trend is striking in viticulture, since wine production is largely shaped by the varying drinking attitudes of environment-friendly consumers. Using 1H NMR, the compositions of grape berries, collected at harvest in 2009 and 2011, in experimental plots cultivated either with biodynamic or organic methods, were compared. Although the analysis provides a comprehensive metabolic profile of berries, the resulting distinctive pattern consists of a few molecules. Lower content of sugars, coumaric and caffeic acids, as well as higher amount of γ-aminobutyric acid (GABA) were observed in biodynamic grapes. The 1H NMR foodomics approach evidenced a diverse fruit metabolome that could be associated to a different physiological response of plants to the agronomic environment
Metabolic changes of genetically engineered grapes (Vitis vinifera L.) studied by 1H-NMR, metabolite heatmaps and iPLS
No full textIntroduction: The Deficiens Homologue 9-iaaM (DefH9-iaaM) gene is an ovule-specific auxin-synthesizing gene
which is expressed specifically in placenta/ovules and promotes auxin-synthesis. It was introduced into the genome
of two grape cultivars Thompson Seedless and Silcora and both transgenic cultivars had an increased number of
berries per bunch.
Objectives: This study investigates the down-stream metabolic changes of Silcora and Thompson seedless grape
cultivars when genetically modified through the insertion of the DefH9-iaaM gene into their genome.
Methods: The effects of the genetic modification upon the grape metabolome were evaluated through 1H-NMR and
exploratory data analysis. Chemometric tools such as Interval Partial Least Squares regression and metabolite
heatmaps were employed for scrutinizing the changes in the transgenic metabolome as compared to the wild type
one.
Results: The results show that the pleiotropic effect on the grape metabolome as a function of the gene modifications is relatively low, although the insertion of the transgene caused a decrement in malic acid and proline and an increment in p-coumaric acid content. In addition, the concentration of malic acid was successfully correlated
with the number of inserted copies of transgene in the Silcora cultivar, proving that the increased production of berries, promoted by the inserted gene, is achieved at the expense of a decrement in malic acid concentration.
Conclusion: NMR together with chemometrics is able to identify specific metabolites that were up- or down regulated
in the genetically engineered plants allowing highlighting alterations in the down-stream metabolic pathways
due to the up-stream genetic modifications
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
