1,720,957 research outputs found
Olive chain by-products for the functionalization of foods
Full text linkL'industria dell'olio d'oliva genera un numero importante di sottoprodotti, come le acque di scarico delle olive, la sansa di oliva e le foglie di ulivo. È stato dimostrato che questi scarti vegetali sono ricchi degli stessi composti fenolici presenti anche nell'olio d'oliva. Tuttavia, i sottoprodotti di olio d'oliva non sono ancora stati sfruttati su scala industriale, ad esempio come fonti di composti bioattivi. A tal fine, è necessario studiare a fondo in che modo le condizioni di lavorazione (pretrattamento della materia prima, estrazione, ecc.) influenzano il potenziale di bioattività, nonché esplorare nuove applicazioni nell'industria alimentare. Pertanto, l'obiettivo principale di questa tesi era legato alla possibilità di utilizzare i sottoprodotti oleari ricchi di composti polifenolici per la formulazione di nuovi alimenti funzionali. Per realizzare nuovi alimenti è necessario considerare che la potenziale incorporazione di sottoprodotti nella formulazione alimentare potrebbe alterare le proprietà sensoriali, suggerendo quindi che un'attenta selezione del tipo e la quantità di questi ingredienti e le opportune opzioni tecnologiche, dovrebbero essere adottate. In particolare, in questa attività di ricerca sono stati studiati gli effetti dei metodi di essiccazione applicati agli estratti dai sottoprodotti dell'olio di oliva sul contenuto di polifenoli e sulla capacità antiossidante. Estrazione di liquidi supercritici, estrazione liquida pressurizzata e estrazione assistita ad ultrasuoni sono stati adottati per scegliere le migliori condizioni di estrazione da applicare ai sottoprodotti. La sansa d'oliva fresca e le foglie di olivo sono state essiccate all'aria a basse temperature per preservare i composti bioattivi e poi utilizzate per alimentare la fortuna. Le acque reflue dei mulini sono state pretrattate dalla tecnologia a membrana, con il duplice scopo di ridurre l'acqua di scarico del carico organico e recuperare i polifenoli. Questa tecnologia, attraverso l'uso di quattro membrane in cascata di microfiltrazione, ultrafiltrazione, nanofiltrazione e osmosi inversa è in grado di estrarre composti polifenolici. Innovativi prodotti a base di cerali e di pesce sono stati realizzati utilizzando questi sottoprodotti ricchi di molecole bioattive. I prodotti alimentari arricchiti sono stati caratterizzati per il contenuto di composti bioattivi, per le proprietà sensoriali e quindi sottoposti a digestione in vitro allo scopo di valutare la bioaccessibilità dei polifenoli totali. I risultati sperimentali sono molto interessanti e sottolineano che i sottoprodotti dell'olio d'oliva potrebbero essere valorizzati come ingredienti promettenti per realizzare nuovi prodotti ricchi di composti fenolici, affrontando anche il problema dell'inquinamento ambientale.The olive oil industry generates an important number of by-products, such as olive mill waste water, olive pomace and olive leaves. It has been demonstrated that these vegetable wastes are rich in almost all the phenolic compounds which are present in olive oil. Nevertheless, olive oil by-products have not yet been exploited at industrial scale, for example as sources of bioactive compounds. For this purpose, it is necessary to study how the processing conditions (raw material pre-treatment, extraction, etc.) affect their properties, as well as explore new applications in the food industry. Therefore, the main goal of this thesis was related to the possibility of using olive oil by-products for the formulation of new fortified foods. To this aim, it was necessary to consider that the potential incorporation of by-products into food formulation could alter the sensory properties, thus suggesting that careful selection of the type and the amount of these ingredients and proper technological options, should be adopted. Specifically, in this research activity the effects of drying methods applied to the extracts from olive oil by-products on the polyphenol content and antioxidant capacity were investigated. Supercritical fluid extraction, pressurized liquid extraction and ultrasonic assisted extraction were adopted to choose the best extraction conditions to be applied to by-products. Fresh olive pomace and olive leaves were air dried at low temperatures to preserve bioactive compounds and then used to fortity food. Olive mill waste water was pretreated by membrane technology, with the dual aims of reducing the organic load waste water and recovering polyphenols. This technology, through the use of four membranes in cascade of microfiltration, ultrafiltration, nanofiltration and reverse osmosis is able to extract polyphenolic compounds. Innovative ceral-based and fish-based products were realized using these by-products rich in bioactive molecules. The enriched food products were characterized for the content of bioactive compounds, for sensory properties and then subjected to in vitro digestion with to purpose of evaluating the bioaccessibility of total polyphenols. The experimental results are very interesting and highlight that olive oil byproducts could be valorized as promising ingredients to realize new products rich in phenolic compounds, also facing the problem of the environmental pollution
Fish burger enriched by olive oil industrial by‐product
No full textOil industry produces large volume of waste, which represents a disposal and a potential environmental pollution problem. Nevertheless, they are also promising sources of compounds that can be recovered and used as valuable substances. The aim of this work is to exploit solid olive by‐products, in particular dry olive paste flour (DOPF) coming from Coratina cultivar, to enrich fish burger and enhance the quality characteristics. In particular, the addition of olive by‐products leads to an increase of the phenolic content and the antioxidant activity; however, it also provokes a deterioration of sensory quality. Therefore, to balance quality and sensory characteristics of fish burgers, three subsequent phases have been carried out: first, the quality of DOPF in terms of phenolic compounds content and antioxidant activity has been assessed; afterward, DOPF has been properly added to fish burgers and, finally, the formulation of the enriched fish burgers has been optimized in order to improve the sensory quality. Results suggested that the enriched burgers with 10% DOPF showed considerable amounts of polyphenols and antioxidant activity, even though they are not very acceptable from the sensory point of view. Pre‐treating DOPF by hydration/extraction with milk, significantly improved the burger sensory quality by reducing the concentration of bitter components
Active packaging solution to prolong the shelf life of rocket salad
No full textThe best packaging conditions for rocket salad were assessed by subsequent experimental trials. In the first step, a preliminary screening of different packaging materials was performed and two micro-perforated oriented polypropylene films with different micro-hole diameters (90 and 110 mu m) were selected as best packaging solutions. In the subsequent experimental step, modified headspace conditions were applied without any improvement on product quality. In the last step, the effects of an ethylene adsorbent were analysed. Rocket salad packaged in both films with the ethylene adsorbent recorded a shelf life of about 16 days, compared to the control samples that remained acceptable for 13 days. During storage, the microbial quality (mesophilic and psychrotrophic bacteria, pseudomonadaceae, lactic acid bacteria, yeasts, total coliforms and enterobacteriacae), the pH, the colour changes and the main sensory parameters were also monitored.European program 'Comprehensive approach to enhance quality and safety of ready to eat fresh products (QUAF-ETY)'This work was financially supported by the European program 'Comprehensive approach to enhance quality and safety of ready to eat fresh products (QUAFETY)'
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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