1,720,962 research outputs found
A non-targeted high-resolution mass spectrometry approach for the assessment of the geographical origin of durum wheat
No full textThe assessment of durum wheat geographical origin is an important and emerging challenge, due to the added value that a claim of origin could provide to the raw material itself, and subsequently to the final products (i.e. pasta). Up to now, the typical approach presented in literature is the evaluation of different isotopic ratios of the elements, but other techniques could represent an interesting and even more powerful alternative. In this study, using a non-targeted high‐resolution mass spectrometry approach, a selection of chemical markers related to the geographical origin of durum wheat was provided. Samples of the 2016 wheat campaign were used to set up the model and to select the markers, while samples from the 2018 campaign were used for model and markers validation. Including in the samples set different geographies across different continents, a discrimination through Italian, European and Not European samples is now possible
Changes in proteolysis and volatile fraction of nitrite-free Italian-type salami modified in formulation and processing
No full textNitrite in meat products exerts multiple functions in terms of safety and quality, but it has been related to an increased risk of health issues, and alternatives have been investigated. In this study, Italian-style salamis were prepared with nitrite and ascorbate (CNO2), without nitrite and ascorbate (C0) and without nitrite and with ascorbate, green tea, grape seed and olive extracts (C0A). The products showed specific features in terms of peptides, free amino acids and volatiles, according to the technology applied for their production. The variations in peptides and free amino acids are likely due to process modifications, as the applied temperature and the time needed for pH decrease. Most volatile compounds, whether generated by known biochemical pathways or by ingredients (spices), differed between salami groups. The changes detected in the chemical parameters analysed provide some insights into the impact on product characteristics due to the process changes applied to replace nitrite removal.Nitrite used in meat products for safety aspects is related to health risks; a replacement with natural components (green tea, grape and olive extracts) has been studied in salami. Products were characterised in terms of amino acids, peptides and volatile compound profiles. Differences were related to the applied production process. imag
Reduction in the brining time in parmigiano reggiano cheese production minimally affects proteolysis, with no effect on sensory properties
No full textBrine soaking is one of the most important steps in the production of Parmigiano Reggiano cheese, since it determines the amount of salt in the final product. Reduction in salt in Parmigiano Reggiano cheese might be important for improving its nutritional profile, but it could affect the manufacturing processes by altering proteolysis and consequently the product quality. In this study, for the first time, salt reduction was explored at the industrial level on real cheese samples manufactured in a local dairy. In particular, 20 wheels were produced with conventional (18 days, 10 wheels) and shorter (12 days, 10 wheels) brining steps. In every group, wheels were studied at two different ripening times, 15 and 30 months. A shorter brining time resulted in an average 12% decrease in salt content. A full characterization of free amino acids and peptides was performed by LC-MS on all samples. Free amino acids and peptides, as expected, increased with ripening, due to proteolysis, with samples having low salt content showing a slightly faster increase when compared to standard ones, hinting to a slightly accelerated proteolytic process. Nonetheless, low-salt and conventional cheeses shared similar sensory profiles at both ripening times
Non-targeted high-resolution mass spectrometry study for evaluation of milk freshness
No full textMilk freshness is an important parameter for both consumers' health and quality of milk-based products. Up to now there have been neither analytical methods nor specific parameters to uniquely define milk freshness from a complete and univocal chemical perspective. In this study, 8 molecules were selected and identified as responsible for milk aging, using a liquid chromatography–high-resolution mass spectrometry approach followed by chemometric data elaboration. For model setup and marker selection, 30 high-quality pasteurized fresh milk samples were collected directly from the production site and analyzed immediately and after storage at 2 to 8°C for 7 d. The markers were then validated by challenging the model with a set of 10 milk samples, not previously analyzed. Our results demonstrated that the markers identified within this study can be successfully used for the correct classification of non-fresh milk samples, complementing and successfully enhancing parallel evaluations obtainable through sensory measures
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
Processing of raw donkey milk by pasteurisation and UV-C to produce freeze-dried milk powders: The effect on protein quality, digestibility and bioactive properties
No full textVariations 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
Synthesis, spectroscopic and structural characterization and solution stability of ruthenium sandwich complexes containing 1,8-naphthalimide ligands
No full textTwo different N-substituted naphthalimide ligands 1 (bearing a phenyl on the imide nitrogen) and 2 (bearing a benzyl on the imide nitrogen) have been synthesized and reacted with the cationic organometallic fragment [Cp*Ru(ACN)3]PF6. Ligand 1 brings to the formation of a sandwich complex (3Naph) where Ru is positioned on the naphthalene platform, while the N-imide phenyl substituent is not involved in coordination. This has been proven by single-crystal X-ray diffraction analysis conducted on crystals of 3Naph, revealing the first sandwich complex structurally characterized containing a naphthaleneimide ligand η6-coordinated to a metal. Ligand 2 shows instead a different behavior, leading to the formation of two isomeric complexes (4Naph and 4Bz), where Ru is placed on the naphthalene platform and on the N-imide benzyl substituent, in a rough 1:1 ratio. Complex 3Naph results very labile in coordinating solvents, such as acetonitrile, where it undergoes a fast and quantitative ligand solvolysis, with formation of free 1 and [Cp*Ru(ACN)3]PF6. In the cases of complexes 4, only complex 4Naph undergoes a fast and quantitative ligand solvolysis once dissolved in acetonitrile, whereas complex 4Bz results more stable
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
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