Evaluation of Tunisian olive oils from different cultivars

[Excerpt] Olive oil is a highly appreciated food product due to sensory and healthy attributes, being quite prone to frauds. So, physicochemical evaluation of olive oils is legally required. In this study, 43 olive oil samples produced in Tunisia from different olive cultivars (groups: Sahli cv – 11 samples; Chetoui cv- 26 samples; and, Other cvs – 4 samples including Leguim cv and Arbequina cv) were physicochemically evaluated taking into account: (i) free acidity (FA), K232 and K270 extinction coefficients, K, and, peroxide values (PV), required for quality level classification (i.e., extra-virgin, virgin and lampante olive oil: EVOO, VOO and LOO); and (ii) other useful data for olive oil overall characterization (total phenols (TP); antioxidant capacity (DPPH); and, oxidative stability (OS)). Based on the levels found for FA, PV and extinction coefficients (K232, K270 and K), the 43 olive oils were classified as: EVOO (4 samples), VOO (5 samples) and LOO (33 samples). [...]This work was financially supported by Project POCI-01-0145-FEDER-006984 – Associate Laboratory LSRE-LCM and by Project UID/QUI/00616/2013 – CQ-VR both funded by FEDER through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014)

Characterization of commercial Tunisian monovarietal olive oils produced from autochthonous olive cultivars

Tunisian commercial monovarietal olive oils, produced from two predominant autochthonous olive cultivars (cvs Chétoui and Oueslati) and another less investigated olive cultivar (cv Sahli) were studied. Chemical and sensory data have shown that most olive oils should be classified as lampante olive oil, pointing out the need of improving producing and/or storage conditions. Sahli olive oils showed the lowest total phenols content (157±48 mg/kg), oxidative stability (6.5±2.1 h), DPPH scavenging activity (68%±14) and monounsaturated fatty acids content (63.1%±3.1). These olive oils had the highest saturated and polyunsaturated fatty acids contents (19.9%±2.4 and 16.9%±1.4) as well as total tocopherols levels (222±49 mg/kg). Finally, the information of 12 selected parameters (total phenols, oxidative stability, nine fatty acids and -tocopherol), allowed establishing a linear discriminant model that correctly classified olive oils according to the olive cultivar with predictive rates of 90%±8. Heptadecenoic, behenic and eicosenoic acids were the three fatty acids identified as the most relevant chemical markers of Sahli olive oils.This work was financially supported by Project POCI-01– 0145-FEDER-006984 – Associate Laboratory LSRE-LCM, Project UID/QUI/00616/2013 – CQ-VR, and strategic project PEst-OE/AGR/UI0690/2014 – CIMO all funded by FEDER - Fundo Europeu de Desenvolvimento Regional through COMPETE2020 - Programa Operacional Competitividade e Internacionalização (POCI) – and by national funds through FCT - Fundação para a Ciência e a Tecnologia, Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/BD/104038/2014). Souheib Oueslati is grateful for the support of the Tunisian Ministry of Agriculture.info:eu-repo/semantics/publishedVersio

Application of an electronic tongue for Tunisian olive oils' classification according to olive cultivar or physicochemical parameters

Olive oil commercialization has a great impact on the economy of several countries, namely Tunisia, being prone to frauds. Therefore, it is important to establish analytical techniques to ensure labeling correctness concerning olive oil quality and olive cultivar. Traditional analytical techniques are quite expensive, time consuming and hardly applied in situ, considering the harsh environments of the olive industry. In this work, the feasibility of applying a potentiometric electronic tongue with cross-sensitivity lipid membranes to discriminate Tunisian olive oils according to their quality level (i.e., extra virgin, virgin or lampante olive oils) or autochthonous olive cultivar (i.e., cv Chétoui and cv Shali) was evaluated for the first time. Linear discrimination analysis coupled with the simulated annealing variable selection algorithm showed that the signal profiles of olive oils hydroethanolic extracts allowed olive oils discrimination according to physicochemical quality level (classification model based on 25 signals enabling 84 ± 9% correct classifications for repeated K-fold cross-validation), and olive cultivar (classification model based on 20 signals with an average sensitivity of 94 ± 6% for repeated K-fold cross-validation), regardless of the geographical origin and olive variety or the olive quality, respectively. The results confirmed, for the first time, the potential discrimination of the electronic tongue, attributed to the observed quantitative response (sensitivities ranging from 66.6 to +57.7 mV/decade) of the E-tongue multi-sensors towards standard solutions of polar compounds (aldehydes, esters and alcohols) usually found in olive oils and that are related to their sensory positive attributes like green and fruity.This work was financially supported by Project POCI-01–0145-FEDER-006984–Associate Laboratory LSRE-LCM and by Project UID/QUI/00616/2013–CQ-VR both funded by FEDER—Fundo Europeu de Desenvolvimento Regional through COMPETE2020-Programa Operacional Competitividade e Internacionalização (POCI)—and by national funds through FCTFundação para a Ciência e a Tecnologia, Portugal. Strategic funding of UID/BIO/04469/2013 unit is also acknowledged. Nuno Rodrigues thanks FCT, POPH-QREN and FSE for the Ph.D. Grant (SFRH/ BD/104038/2014).info:eu-repo/semantics/publishedVersio

Querying probabilistic XML

XML probabiliste est un modèle probabiliste pour les bases de données incertaines semi-structurées, avec des applications telles que l'intégration incertaine de données, l'extraction d'informations ou le contrôle probabiliste de versions. Nous explorons dans cette thèse une solution efficace pour l'évaluation des requêtes tree-pattern avec jointures sur ces documents, ou, plus précisément, pour l'approximation de la probabilité d'une requête booléenne sur un document probabiliste. L'approche repose sur, d'une part, la production de la provenance probabiliste de la requête posée, et, d'autre part, la recherche d'une stratégie optimale pour estimer la probabilité de cette provenance. Cette deuxième partie s'inspire des approches des optimiseurs de requêtes: l'exploration de différents plans d'évaluation pour différentes parties de la formule et l'estimation du coût de chaque plan, suivant un modèle de coût établi pour les algorithmes de calcul utilisés. Nous démontrons l'efficacité de cette approche sur des jeux de données utilisés dans des travaux précédents sur l'interrogation des bases de données XML probabilistes, ainsi que sur des données synthétiques.Probabilistic XML is a probabilistic model for uncertain tree-structured data, with applications to data integration, information extraction, or uncertain version control. We explore in this dissertation efficient algorithms for evaluating tree-pattern queries with joins over probabilistic XML or, more specifically, for approximating the probability of each item of a query result. The approach relies on, first, extracting the query lineage over the probabilistic XML document, and, second, looking for an optimal strategy to approximate the probability of the propositional lineage formula. ProApproX is the probabilistic query manager for probabilistic XML presented in this thesis. The system allows users to query uncertain tree-structured data in the form of probabilistic XML documents. It integrates a query engine that searches for an optimal strategy to evaluate the probability of the query lineage. ProApproX relies on a query-optimizer--like approach: exploring different evaluation plans for different parts of the formula and predicting the cost of each plan, using a cost model for the various evaluation algorithms. We demonstrate the efficiency of this approach on datasets used in a number of most popular previous probabilistic XML querying works, as well as on synthetic data. An early version of the system was demonstrated at the ACM SIGMOD 2011 conference. First steps towards the new query solution were discussed in an EDBT/ICDT PhD Workshop paper (2011). A fully redesigned version that implements the techniques and studies shared in the present thesis, is published as a demonstration at CIKM 2012. Our contributions are also part of an IEEE ICD

Efficient query evaluation over probabilistic XML with long-distance dependencies

We address the problem of querying probabilistic semistructured databases in view of the tradeoff between the efficiency of evaluation and the ability to model probabilistic dependencies between elements of the tree. We introduce, through a discussion of several challenges, the ProApproX query processor over probabilistic XML as a first step towards building a full-fletched probabilistic semistructured data management system. ProApproX aims at efficient data querying of a comparatively larger subset of the XPath query language than was processed by related systems, through techniques of exact calculations or efficient approximations of the result probability. This paper describes PhD work carried out at Télécom ParisTech under the guidance of Pierre Senellart. 1

Interrogation des bases de données XML probabilistes

Probabilistic XML is a probabilistic model for uncertain tree-structured data, with applications to data integration, information extraction, or uncertain version control. We explore in this dissertation efficient algorithms for evaluating tree-pattern queries with joins over probabilistic XML or, more specifically, for approximating the probability of each item of a query result. The approach relies on, first, extracting the query lineage over the probabilistic XML document, and, second, looking for an optimal strategy to approximate the probability of the propositional lineage formula. ProApproX is the probabilistic query manager for probabilistic XML presented in this thesis. The system allows users to query uncertain tree-structured data in the form of probabilistic XML documents. It integrates a query engine that searches for an optimal strategy to evaluate the probability of the query lineage. ProApproX relies on a query-optimizer--like approach: exploring different evaluation plans for different parts of the formula and predicting the cost of each plan, using a cost model for the various evaluation algorithms. We demonstrate the efficiency of this approach on datasets used in a number of most popular previous probabilistic XML querying works, as well as on synthetic data. An early version of the system was demonstrated at the ACM SIGMOD 2011 conference. First steps towards the new query solution were discussed in an EDBT/ICDT PhD Workshop paper (2011). A fully redesigned version that implements the techniques and studies shared in the present thesis, is published as a demonstration at CIKM 2012. Our contributions are also part of an IEEE ICDEXML probabiliste est un modèle probabiliste pour les bases de données incertaines semi-structurées, avec des applications telles que l'intégration incertaine de données, l'extraction d'informations ou le contrôle probabiliste de versions. Nous explorons dans cette thèse une solution efficace pour l'évaluation des requêtes tree-pattern avec jointures sur ces documents, ou, plus précisément, pour l'approximation de la probabilité d'une requête booléenne sur un document probabiliste. L'approche repose sur, d'une part, la production de la provenance probabiliste de la requête posée, et, d'autre part, la recherche d'une stratégie optimale pour estimer la probabilité de cette provenance. Cette deuxième partie s'inspire des approches des optimiseurs de requêtes: l'exploration de différents plans d'évaluation pour différentes parties de la formule et l'estimation du coût de chaque plan, suivant un modèle de coût établi pour les algorithmes de calcul utilisés. Nous démontrons l'efficacité de cette approche sur des jeux de données utilisés dans des travaux précédents sur l'interrogation des bases de données XML probabilistes, ainsi que sur des données synthétiques