1,720,960 research outputs found
Electronic Nose in Combination with Chemometrics for Characterization of Geographical Origin and Agronomic Practices of Table Grape
No full textNowadays, the protection of food quality attributes (such as geographical origin or method of production) from frauds and adulterations is one of the main concerns of honest producers and aware consumers. In this study, table grape samples were analyzed by using an electronic nose aiming to evaluate the usefulness of sensor data in combination with statistical analysis in discriminating the agronomic practice (conventional vs. organic farming) and the geographical origin of table grape. Principal component analysis (PCA) showed inadequate clustering of samples according to places of production or agronomic practice; thus for classification purpose, a supervised approach was carried out. In particular, linear discriminant analyses (LDA) was used, resulting in mean prediction abilities of 83.6% and 84.6% for the discrimination of farming method and geographical origin, respectively. Considering the results obtained herein, it can be concluded that sensor data combined with chemometrics showed a good potential in discriminating origin as well as method of production of table grapes especially if compared with other analytical techniques both in terms of time and cost of analyses
Chemical Profile of the Carpino Broad Bean by Conventional and Innovative Physicochemical Analyses
No full textA detailed chemical characterization of a typical Apulian legume, the Carpino broad bean, was obtained. Crude proteins, moisture, phosphorus, ash and energy content were evaluated on starting seeds, half-ripening beans and final products. Stable isotope ratios (15N/14N and 13C/12C), major (Ca, Mg, Na and K) and trace metals (Zn, Mo, Mn, Cu, Fe, Cr, Cd, Ni and Co) were also assessed. Moreover, information on a large number of metabolites was obtained by 1H high-resolution magic-angle spinning nuclear magnetic resonance spectroscopy. The data revealed that Carpino broad bean dry seeds supply adequate protein and energy content, 28.1% and 326kcal, respectively, being also a good source of macro- and microelements. In particular, the iron content was 46.0mg/kg: this potentially provides about 33% of the recommended daily allowance by a 100g serving. Moreover, the analyzed samples seem to lack elements considered potentially harmful for health. Practical Applications: The Carpino broad bean is a native faba bean cultivar, traditionally cultivated in small quantities in Gargano (Southern Italy). It is commonly considered a traditional food product with interesting nutritional properties. At present, the Carpino broad bean has still not received an official European label as typical product, but it is a Slow Food presidium, this remarks its considerable socio-cultural, nutritional and environmental values. Even if restricted to a limited geographic area, this typical and appreciable cultivation should be protected from extinction, preserving territory identity and working techniques; therefore, it is essential to explore ways to prove the Carpino broad bean quality and peculiarities, starting from a physicochemical characterization, that has not been presented in detail until now, and that could be a considerable basis for an official valorization of this product, for instance, for the attainment of EU Protected Designation of Origin/Protected Geographical Indication (EU PDO/PGI) labels
Studying ancient crop provenance: implications from delta C-13 and delta N-15 values of charred barley in a Middle Bronze Age silo at Ebla (NW Syria)
No full textThe discovery of a storeroom full of barley and other cereals (L.9512) in the proto-historic site of Ebla has provided a unique opportunity to study the centralized storage system of the early city-state from a different perspective. Epigraphic evidence available within the site reveals a complex system of taxation which included gathering grain tributes from satellite sites and redistributing semi-finished products such as flour. In this paper, we intend to explore the possibilities of a combined approach to studying the storage system, based on estimated barley grain volumes and delta C-13-delta N-15 analyses. This approach is used to distinguish between grain from different harvesting sites and to identify any grain cultivated using special agricultural practices (e.g. manuring or irrigation). The basic assumption for this kind of analysis is that the growth-site conditions, natural or anthropogenic, of harvested cereals are reflected in their grain size and delta C-13-delta N-15 values. Since the remains found in the storeroom were charred, the first task was to evaluate the effect of carbonization on the delta C-13-delta N-15 and the size of the grains. Thus, the effect of charring was tested on modern samples of Syrian barley landraces. Once it had been ascertained that fresh grains reduced to charred remains retain their original biometric and isotopic traits, the ancient material was examined. Thirteen groups were identified, each characterized by a specific average volume and specific carbon and nitrogen values. The analysis revealed that what had first appeared to be a homogeneous concentration of grain was in fact an assemblage of barley harvested from different sites
Isotope ratio mass spectrometry in combination with chemometrics for characterization of geographical origin and agronomic practices of table grape
No full textBACKGROUND: Although table grape is one of the most cultivated and consumed fruits worldwide, no study has been reported on its geographical origin or agronomic practice based on stable isotope ratios. This study aimed to evaluate the usefulness of isotopic ratios (i.e. 2H/1H, 13C/12C, 15N/14N and 18O/16O) as possible markers to discriminate the agronomic practice (conventional versus organic farming) and provenance of table grape. RESULTS: In order to quantitatively evaluate which of the isotopic variables were more discriminating, a t test was carried out, in light of which only δ13C and δ18O provided statistically significant differences (P ≤ 0.05) for the discrimination of geographical origin and farming method. Principal component analysis (PCA) showed no good separation of samples differing in geographical area and agronomic practice; thus, for classification purposes, supervised approaches were carried out. In particular, general discriminant analysis (GDA) was used, resulting in prediction abilities of 75.0 and 92.2% for the discrimination of farming method and origin respectively. CONCLUSION: The present findings suggest that stable isotopes (i.e. δ18O, δ2H and δ13C) combined with chemometrics can be successfully applied to discriminate the provenance of table grape. However, the use of bulk nitrogen isotopes was not effective for farming method discrimination. © 2016 Society of Chemical Industry
Investigating the impact of botanical origin and harvesting period on carbon stable isotope ratio values (13C/12C) and different parameter analysis of Greek unifloral honeys: A chemometric approach for correct botanical discrimination
No full textThe aim of this study was to investigate the impact of botanical origin and harvesting period on carbon stable isotope ratio (13C/12C), colour intensity (CI), radical scavenging activity (%RSA), P and Sn content of Greek unifloral honeys. Thus, twenty-four honey samples were collected during harvesting periods 2011–2012 and 2012–2013, from four different regions in Greece. 13C/12C ratios and minerals were determined using isotope ratio mass spectrometry (IRMS) and inductively coupled plasma optical–emission spectroscopy (ICP-OES), respectively. CI and %RSA were measured using spectrophotometric assays. Results showed that only 13C/12C values and %RSA were affected by both botanical origin and harvesting period (P < 0.05). Applying then chemometric analyses to the collected data set, honeys were correctly classified according to honey type (correct classification rate 87.5% and 79.2% using the original and cross-validation method, respectively). The use of different origin parameters has the potential to aid in honey authentication
Discrimination of geographical origin of oranges (Citrus sinensis L. Osbeck) by mass spectrometry-based electronic nose and characterization of volatile compounds
Full text linkAn untargeted method using headspace solid-phase microextraction coupled to electronic nose based on mass spectrometry (HS-SPME/MS-eNose) in combination with chemometrics was developed for the discrimination of oranges of three geographical origins (Italy, South Africa and Spain). Three multivariate statistical models, i.e. PCA/LDA, SELECT/LDA and PLS-DA, were built and relevant performances were compared. Among the tested models, SELECT/LDA provided the highest prediction abilities in cross-validation and external validation with mean values of 97.8% and 95.7%, respectively. Moreover, HS-SPME/GC-MS analysis was used to identify potential markers to distinguish the geographical origin of oranges. Although 28 out of 65 identified VOCs showed a different content in samples belonging to different classes, a pattern of analytes able to discriminate simultaneously samples of three origins was not found. These results indicate that the proposed MS-eNose method in combination with multivariate statistical analysis provided an effective and rapid tool for authentication of the orange's geographical origin
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
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