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Papers by Tullia Gallina Toschi

Research paper thumbnail of Supporting the Sensory Panel to Grade Virgin Olive Oils: An In-House-Validated Screening Tool by Volatile Fingerprinting and Chemometrics

Research paper thumbnail of An HS-GC-IMS Method for the Quality Classification of Virgin Olive Oils as Screening Support for the Panel Test

Foods, 2020

Sensory evaluation, carried out by panel tests, is essential for quality classification of virgin... more Sensory evaluation, carried out by panel tests, is essential for quality classification of virgin olive oils (VOOs), but is time consuming and costly when many samples need to be assessed; sensory evaluation could be assisted by the application of screening methods. Rapid instrumental methods based on the analysis of volatile molecules might be considered interesting to assist the panel test through fast pre-classification of samples with a known level of probability, thus increasing the efficiency of quality control. With this objective, a headspace gas chromatography-ion mobility spectrometer (HS-GC-IMS) was used to analyze 198 commercial VOOs (extra virgin, virgin and lampante) by a semi-targeted approach. Different partial least squares-discriminant analysis (PLS-DA) chemometric models were then built by data matrices composed of 15 volatile compounds, which were previously selected as markers: a first approach was proposed to classify samples according to their quality grade an...

Research paper thumbnail of Summary report on sensory-related socio-economic and sensory science literature about organic food products

Organic food's initial attraction to the public was that it was perceived to be healthier an... more Organic food's initial attraction to the public was that it was perceived to be healthier and tastier, but scientists and policy makers have mainly stressed the benefits to the environment of organic and sustainable farming. Scientific support for marketing actions addressed to those who want to be healthier and who want to enjoy better taste, and are willing to pay more for these benefits is scarce. Past research has produced little clear evidence about the importance of sensory characteristics such as taste, smell, appearance etc in consumers' ...

Research paper thumbnail of Toward a Harmonized and Standardized Protocol for the Determination of Total Hydroxytyrosol and Tyrosol Content in Virgin Olive Oil (VOO). Extraction Solvent

European Journal of Lipid Science and Technology, 2018

The determinationof the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content of virgin olive oil... more The determinationof the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content of virgin olive oil is of utmost interest for the International Olive Council (IOC), food authorities, producers and distributorsafter the issuing of a health claim that "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress".To address the need of a harmonized and standardized protocol the present study focuseson the extraction solvent of the polar fraction. Aqueous mixtures of methanol and acetonitrile of equal polarity were prepared and comparatively examined. Different analytical approaches (Folin-Ciocalteu assay, reversed phase chromatography-diode array-fluorescence detection, LC-HRMS, LC-TOF, LC-TQd, 1 H-NMR) were applied to highlight the extracting efficiency of the tested mixtures regarding the phenolic content and composition.The use of acetonitrile had not a clear positive effect that could compensate its higher cost, commercial availability and toxicity. The findings justify further why methanol:water, 80:20 v/v should be retained in a future IOC protocol for the accurate and repeatable determination of total Htyr and Tyr content, which isnecessary to support the health claim for "olive oil polyphenols". Practical applications: The development of a harmonized and standardized methodology for the determination of total Htyr and Tyr content in an explicit manner is a request of the olive oil sector. Providing a tool that can be introduced easily in the olive industry and official laboratories for the control of the label that bears a health claim for 'olive oil polyphenols,' is also requested by the consumers and the IOC. In this view, the present study contributes to the cornerstone that is the standardization of the extraction solvent system.

Research paper thumbnail of Flash Gas Chromatography in Tandem with Chemometrics: A Rapid Screening Tool for Quality Grades of Virgin Olive Oils

Foods

This research aims to develop a classification model based on untargeted elaboration of volatile ... more This research aims to develop a classification model based on untargeted elaboration of volatile fraction fingerprints of virgin olive oils (n = 331) analyzed by flash gas chromatography to predict the commercial category of samples (extra virgin olive oil, EVOO; virgin olive oil, VOO; lampante olive oil, LOO). The raw data related to volatile profiles were considered as independent variables, while the quality grades provided by sensory assessment were defined as a reference parameter. This data matrix was elaborated using the linear technique partial least squares-discriminant analysis (PLS-DA), applying, in sequence, two sequential classification models with two categories (EVOO vs. no-EVOO followed by VOO vs. LOO and LOO vs. no-LOO followed by VOO vs. EVOO). The results from this large set of samples provide satisfactory percentages of correctly classified samples, ranging from 72% to 85%, in external validation. This confirms the reliability of this approach in rapid screening ...

Research paper thumbnail of Multi-analytical approach for monitoring the freezing process of a milkshake based product

Journal of Food Engineering, 2016

Research paper thumbnail of Rapid direct analysis to discriminate geographic origin of extra virgin olive oils by flash gas chromatography electronic nose and chemometrics

At present, the geographical origin of extra virgin olive oils can be ensured by documented trace... more At present, the geographical origin of extra virgin olive oils can be ensured by documented traceability, although chemical analysis may add information that is useful for possible confirmation. This preliminary study investigated the effectiveness of flash gas chromatography electronic nose and multivariate data analysis to perform rapid screening of commercial extra virgin olive oils characterized by a different geographical origin declared in the label. A comparison with solid phase micro extraction coupled to gas chromatography mass spectrometry was also performed. The new method is suitable to verify the geographic origin of extra virgin olive oils based on principal components analysis and discriminant analysis applied to the volatile profile of the headspace as a fingerprint. The selected variables were suitable in discriminating between ''100% Italian " and ''non-100% Italian " oils. Partial least squares discriminant analysis also allowed prediction of the degree of membership of unknown samples to the classes examined.

Research paper thumbnail of Supporting the Sensory Panel to Grade Virgin Olive Oils: An In-House-Validated Screening Tool by Volatile Fingerprinting and Chemometrics

Research paper thumbnail of An HS-GC-IMS Method for the Quality Classification of Virgin Olive Oils as Screening Support for the Panel Test

Foods, 2020

Sensory evaluation, carried out by panel tests, is essential for quality classification of virgin... more Sensory evaluation, carried out by panel tests, is essential for quality classification of virgin olive oils (VOOs), but is time consuming and costly when many samples need to be assessed; sensory evaluation could be assisted by the application of screening methods. Rapid instrumental methods based on the analysis of volatile molecules might be considered interesting to assist the panel test through fast pre-classification of samples with a known level of probability, thus increasing the efficiency of quality control. With this objective, a headspace gas chromatography-ion mobility spectrometer (HS-GC-IMS) was used to analyze 198 commercial VOOs (extra virgin, virgin and lampante) by a semi-targeted approach. Different partial least squares-discriminant analysis (PLS-DA) chemometric models were then built by data matrices composed of 15 volatile compounds, which were previously selected as markers: a first approach was proposed to classify samples according to their quality grade an...

Research paper thumbnail of Summary report on sensory-related socio-economic and sensory science literature about organic food products

Organic food's initial attraction to the public was that it was perceived to be healthier an... more Organic food's initial attraction to the public was that it was perceived to be healthier and tastier, but scientists and policy makers have mainly stressed the benefits to the environment of organic and sustainable farming. Scientific support for marketing actions addressed to those who want to be healthier and who want to enjoy better taste, and are willing to pay more for these benefits is scarce. Past research has produced little clear evidence about the importance of sensory characteristics such as taste, smell, appearance etc in consumers' ...

Research paper thumbnail of Toward a Harmonized and Standardized Protocol for the Determination of Total Hydroxytyrosol and Tyrosol Content in Virgin Olive Oil (VOO). Extraction Solvent

European Journal of Lipid Science and Technology, 2018

The determinationof the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content of virgin olive oil... more The determinationof the total hydroxytyrosol (Htyr) and tyrosol (Tyr) content of virgin olive oil is of utmost interest for the International Olive Council (IOC), food authorities, producers and distributorsafter the issuing of a health claim that "olive oil polyphenols contribute to the protection of blood lipids from oxidative stress".To address the need of a harmonized and standardized protocol the present study focuseson the extraction solvent of the polar fraction. Aqueous mixtures of methanol and acetonitrile of equal polarity were prepared and comparatively examined. Different analytical approaches (Folin-Ciocalteu assay, reversed phase chromatography-diode array-fluorescence detection, LC-HRMS, LC-TOF, LC-TQd, 1 H-NMR) were applied to highlight the extracting efficiency of the tested mixtures regarding the phenolic content and composition.The use of acetonitrile had not a clear positive effect that could compensate its higher cost, commercial availability and toxicity. The findings justify further why methanol:water, 80:20 v/v should be retained in a future IOC protocol for the accurate and repeatable determination of total Htyr and Tyr content, which isnecessary to support the health claim for "olive oil polyphenols". Practical applications: The development of a harmonized and standardized methodology for the determination of total Htyr and Tyr content in an explicit manner is a request of the olive oil sector. Providing a tool that can be introduced easily in the olive industry and official laboratories for the control of the label that bears a health claim for 'olive oil polyphenols,' is also requested by the consumers and the IOC. In this view, the present study contributes to the cornerstone that is the standardization of the extraction solvent system.

Research paper thumbnail of Flash Gas Chromatography in Tandem with Chemometrics: A Rapid Screening Tool for Quality Grades of Virgin Olive Oils

Foods

This research aims to develop a classification model based on untargeted elaboration of volatile ... more This research aims to develop a classification model based on untargeted elaboration of volatile fraction fingerprints of virgin olive oils (n = 331) analyzed by flash gas chromatography to predict the commercial category of samples (extra virgin olive oil, EVOO; virgin olive oil, VOO; lampante olive oil, LOO). The raw data related to volatile profiles were considered as independent variables, while the quality grades provided by sensory assessment were defined as a reference parameter. This data matrix was elaborated using the linear technique partial least squares-discriminant analysis (PLS-DA), applying, in sequence, two sequential classification models with two categories (EVOO vs. no-EVOO followed by VOO vs. LOO and LOO vs. no-LOO followed by VOO vs. EVOO). The results from this large set of samples provide satisfactory percentages of correctly classified samples, ranging from 72% to 85%, in external validation. This confirms the reliability of this approach in rapid screening ...

Research paper thumbnail of Multi-analytical approach for monitoring the freezing process of a milkshake based product

Journal of Food Engineering, 2016

Research paper thumbnail of Rapid direct analysis to discriminate geographic origin of extra virgin olive oils by flash gas chromatography electronic nose and chemometrics

At present, the geographical origin of extra virgin olive oils can be ensured by documented trace... more At present, the geographical origin of extra virgin olive oils can be ensured by documented traceability, although chemical analysis may add information that is useful for possible confirmation. This preliminary study investigated the effectiveness of flash gas chromatography electronic nose and multivariate data analysis to perform rapid screening of commercial extra virgin olive oils characterized by a different geographical origin declared in the label. A comparison with solid phase micro extraction coupled to gas chromatography mass spectrometry was also performed. The new method is suitable to verify the geographic origin of extra virgin olive oils based on principal components analysis and discriminant analysis applied to the volatile profile of the headspace as a fingerprint. The selected variables were suitable in discriminating between ''100% Italian " and ''non-100% Italian " oils. Partial least squares discriminant analysis also allowed prediction of the degree of membership of unknown samples to the classes examined.