Caracterització de Caves mitjançant cromatografia de líquids

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2018, Tutor: Xavier Saurina PurroyCava is an exceptional kind of sparkling wine with a protected designation of origin (PDO) status from Spain. This beverage is made by the Champanoise method, which requires a secondary fermentation in the bottle. Polyphenols are one of the principal components of Cava. These substances not only are responsible for some of the unique properties of Cava but, also, can be used as chemical descriptors to discriminate among samples of different varieties and compositions. In the present project, 10 types of Cavas from different varieties of grapes were characterized according to their polyphenolic profile, which was obtained by high performance liquid chromatography with UV-visible detection at different wavelengths (250, 280, 310, 370 nm). A total of 18 polyphenols were studied. Two different approaches (chromatograms and integrated peak areas, also referred to as fingerprinting and profiling approaches, respectively) were used to build principal component analysis (PCA) models focused on the differentiation among the samples. Both models presented an excellent discriminant ability. Besides, with the profiling model the most characteristic polyphenolic compounds of each kind of Cava were identified. Finally, the chromatograms registered at 310 nm were used to build partial least squares discriminant analysis (PLS-DA) models which allowed the classification of the Cava samples according to their type, and “unknown” samples belonging to a new test set were correctly assigned to their corresponding classe

Revealing adulterated olive oils by triacylglycerol screening methods: Beyond the official method

Official control methods to detect olive oil (OO) adulteration fail to provide satisfactory consumer protection. Thus, faster and more sensitive screening tools are needed to increase their effectiveness. Here, the official method for adulterant detection in OO was compared with three untargeted screening methods based on triacylglycerol analysis using high-throughput (FIA-HESI-HRMS; HT-GC-MS; HPLC-RID) and pattern recognition techniques (PLS-DA). They were assayed on a set of genuine and adulterated samples with a high natural variability (n = 143). The sensitivity of the official method was 1 for high linoleic (HL) blends at ≥2 % but only 0.39 for high oleic (HO) blends at ≥5 %, while specificity was 0.96. The sensitivity of the screening methods in external validation was 0.90-0.99 for the detection of HL and 0.82-0.88 for HO blends. Among them, HT-GC-MS offered the highest sensitivity (0.94) and specificity (0.76), proving to be the most suitable screening tool for OO authentication

Geographical authentication of virgin olive oil by GC-MS sesquiterpene hydrocarbon fingerprint: Scaling down to the verification of PDO compliance

Nowadays, 144 Protected Designations of Origin (PDO) and Protected Geographical Indications (PGI) under the EU quality schemes correspond to extra virgin olive oil (EVOO). As endorsed by the EU Food Fraud Network, PDO/PGI EVOOs are particularly vulnerable to fraudulent practices because of their high economic value. For this reason, the present study aims to develop an instrumental tool to assess the compliance of EVOO with PDO label-declaration using a large sample set (n = 350). As a case study, PDOs from Catalonia were used. Therefore, discriminant analysis based on the sesquiterpene hydrocarbon fingerprint determined by HS-SPME-GC-MS achieved to correctly classify an average of 93.6% of samples among the four Catalan PDOs, leaving unassigned the 6% of the total sampling (external validation results for 3 iterations). On the other hand, the proposed strategy allowed discriminating each Catalan PDO from non-PDO samples produced in different geographical areas with an efficiency between 95% and 99%

Geographical authentication of virgin olive oil by GC–MS sesquiterpene hydrocarbon fingerprint: Verifying EU and single country label-declaration

According to the last report from the European Union (EU) Food Fraud Network, olive oil tops the list of the most notified products. Current EU regulation states geographical origin as mandatory for virgin olive oils, even though an official analytical method is still lacking. Verifying the compliance of label-declared EU oils should be addressed with the highest priority level. Hence, the present work tackles this issue by developing a classification model (PLS-DA) based on the sesquiterpene hydrocarbon fingerprint of 400 samples obtained by HS-SPME-GC–MS to discriminate between EU and non-EU olive oils, obtaining an 89.6% of correct classification for the external validation (three iterations), with a sensitivity of 0.81 and a specificity of 0.95. Subsequently, multi-class discrimination models for EU and non-EU countries were developed and externally validated (with three different validation sets) with successful results (average of 92.2% of correct classification for EU and 96.0% for non-EU countries).Fil: Quintanilla Casas, Beatriz. Universidad de Barcelona; EspañaFil: Torres Cobos, Berta. Universidad de Barcelona; EspañaFil: Guardiola, Francesc. Universidad de Barcelona; EspañaFil: Servili, Maurizio. Università di Perugia; ItaliaFil: Alonso Salces, Rosa Maria. Universidad Nacional de Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Producción, Sanidad y Ambiente; ArgentinaFil: Valli, Enrico. Università di Bologna; ItaliaFil: Bendini, Alessandra. Università di Bologna; ItaliaFil: Gallina Toschi, Tullia. Università di Bologna; ItaliaFil: Vichi, Stefania. Universidad de Barcelona; EspañaFil: Tres, Alba. Universidad de Barcelona; Españ

Varietal authentication of virgin olive oil: Proving the efficiency of sesquiterpene fingerprinting for Mediterranean Arbequina oils

Virgin olive oil (VOO) is a highly appreciated product fundamental in the Mediterranean diet. Since its sensory attributes are greatly influenced by the olive cultivar, the varietal authentication of VOOs is needed to protect consumers from misleading information. The present study aims to evaluate the suitability of sesquiterpene hydrocarbon (SH) fingerprint as VOO cultivar marker beyond geographical, agronomical and processing conditions. The study was mainly focused on Mediterranean Arbequina oils. SH profile of more than 400 VOOs from 6 counties and 38 different cultivars and coupages was analysed by Headspace Solid Phase Microextraction-Gas Chromatography-Mass Spectrometry (HS-SPME-GC-MS). Partial Least Square-Discriminant Analysis (PLS-DA) classification models were built with the aligned chromatograms. A binary PLS-DA model was built to distinguish 'Arbequina' oils from those of other cultivars (non-'Arbequina' class) and it was externally validated. The results of the external validation showed a 95.1% of overall correct classification confirming the suitability of SH fingerprint as a screening method for the authentication of Arbequina VOO. Also, the discrimination capacity of SH fingerprinting to authenticate VOOs from other cultivars was preliminary explored and promising results were obtained

Large-scale evaluation of shotgun triacylglycerol profiling for the fast detection of olive oil adulteration

Fast and effective analytical screening tools providing new suitable authenticity markers and applicable to a large number of samples are required to efficiently control the global olive oil (OO) production, and allow the rapid detection of low levels of adulterants even with fatty acid composition similar to OO. The present study aims to develop authentication models for the comprehensive detection of illegal blends of OO with adulterants including different types of high linoleic (HL) and high oleic (HO) vegetable oils at low concentrations (2-10%) based on shotgun triacylglycerol (TAG) profile obtained by Flow Injection Analysis-Heated Electrospray Ionisation-High Resolution Mass Spectrometry (FIA-HESI-HRMS) at a large-scale experimental design. The sample set covers a large natural variability of both OO and adulterants, resulting in more than one thousand samples analysed. A combined PLS-DA binary modelling based on shotgun TAG profiling proved to be a fit for purpose screening tool in terms of efficiency and applicability. The external validation resulted in the correct classification of the 86.8% of the adulterated samples (diagnostic sensitivity = 0.87), and the 81.1% of the genuine samples (diagnostic specificity = 0.81), with an 85.1% overall correct classification (efficiency = 0.85)

Large-scale evaluation of shotgun triacylglycerol profiling for the fast detection of olive oil adulteration

Final version is available in open access in publisher’s site.-- This abstract is based on the published article: Beatriz Quintanilla-Casas, Giulia Strocchi, Julen Bustamante, Berta Torres-Cobos, Francesc Guardiola, Wenceslao Moreda, José Manuel Martínez-Rivas, Enrico Valli, Alessandra Bendini, Tullia Gallina Toschi, Alba Tres, Stefania Vichi. Large-scale evaluation of shotgun triacylglycerol profiling for the fast detection of olive oil adulteration. Food Control, Volume 123, 2021, 107851, https://doi.org/10.1016/j.foodcont.2020.107851.-- http://hdl.handle.net/10261/229187Peer reviewe

Geographical authentication of virgin olive oil by GC-MS sesquiterpene hydrocarbon fingerprint: Scaling down to the verification of PDO compliance

Nowadays, 144 Protected Designations of Origin (PDO) and Protected Geographical Indications (PGI) under the EU quality schemes correspond to extra virgin olive oil (EVOO). As endorsed by the EU Food Fraud Network, PDO/PGI EVOOs are particularly vulnerable to fraudulent practices because of their high economic value. For this reason, the present study aims to develop an instrumental tool to assess the compliance of EVOO with PDO label-declaration using a large sample set (n = 350). As a case study, PDOs from Catalonia were used. Therefore, discriminant analysis based on the sesquiterpene hydrocarbon fingerprint determined by HS-SPME-GC-MS achieved to correctly classify an average of 93.6% of samples among the four Catalan PDOs, leaving unassigned the 6% of the total sampling (external validation results for 3 iterations). On the other hand, the proposed strategy allowed discriminating each Catalan PDO from non-PDO samples produced in different geographical areas with an efficiency between 95% and 99%.info:eu-repo/semantics/publishedVersio

Use of a Minimal Microbial Consortium to Determine the Origin of Kombucha Flavor

International audienceMicrobiological, chemical, and sensory analyses were coupled to understand the origins of kombucha organoleptic compounds and their implication in the flavor of the kombucha beverage. By isolating microorganisms from an original kombucha and comparing it to monocultures and cocultures of two yeasts ( Brettanomyces bruxellensis and Hanseniaspora valbyensis ) and an acetic acid bacterium ( Acetobacter indonesiensis ), interaction effects were investigated during the two phases of production. 32 volatile compounds identified and quantified by Headspace-Solid Phase-MicroExtraction-Gas Chromatography/Mass Spectrometry (HS-SPME-GC/MS) were classified according to their origin from tea or microorganisms. Many esters were associated to H. valbyensis , while alcohols were associated to both yeasts, acetic acid to A. indonesiensis , and saturated fatty acids to all microorganisms. Concentration of metabolites were dependent on microbial activity, yeast composition, and phase of production. Sensory analysis showed that tea type influenced the olfactive perception, although microbial composition remained the strongest factor. Association of B. bruxellensis and A. indonesiensis induced characteristic apple juice aroma