Mario Bertuccioli

Saliva Characteristics and Individual Sensitivity to Phenolic Astringent Stimuli

Astringency sensation is due to interactions between salivary proteins and phenols and is based on an increased-friction mechanism. Modifications to the profile of salivary proteins and their concentration could affect tannin/protein reactions and hence the intensity of perceived astringency. Salivary characteristics of 65 subjects were compared after abstention from phenol-containing food and immediately after ingestion of tannic acid. The effect of stimulation on saliva characteristics was expressed in terms of D value, computed as the arithmetic difference between values found in saliva samples from the 2 conditions. Based on D values, subjects were clustered in two groups. Cluster 1 (Cl1, 53 cases) was characterized by low D values thus indicating that the basal saliva condition was quickly restored in these subjects. Cluster 2 (Cl2) was composed of 12 subjects whose basal salivary condition was not quickly restored, particularly in terms of salivary protein concentration and profile and saliva haze-forming capacity. Sensory data showed that subjects capable of maintaining constant saliva characteristics were less sensitive to astringent stimuli than subjects in which the same stimulations induced significant saliva modifications. The results suggest that a large proportion of the population are able to maintain their salivary protein concentration and simultaneously intercept and inactivate dietary tannins.

Optimization of virgin olive oil quality in relation to fruit ripening and storage

Abstract The paper shows a procedure to explore and optimize the relationship between raw material characteristics (fruit ripening and storage grade) and a multidimensional index representing virgin olive oil quality. The utilized procedure has required five different steps: a) flavour profile evaluation of several commercial olive oil samples; b) perceived quality evaluation by COI method; c) selection of sensory variables related to perceived quality; d) identification of chemical markers related to selected sensory variables, e) combination of chemical markers into an olive oil quality index (overall desirability function-D). Utilizing the Central Composite Design, nine oil extractions were made in order to obtain a model able to relate oil quality to olive fruit characteristics (ripening and storage). The procedure proposed, in attaining quality index (desirability function-D), allows to optimize the extraction yield (amount of oil), the oil stability (amount of phenols), and the consumer oil perception related to the amount of trans-2-hexenal and phenols.

Effect of Oenotannin Addition on the Composition of Sangiovese Wines from Grapes with Different Characteristics

Different types of oenotannins were added to Vitis vinifera cv. Sangiovese grapes of various composition and the resulting wine color parameters were measured, including intensity, hue, total phenol index, monomer anthocyanin content, and colored polymeric pigment content. Oenotannins were also tested during pre- and postfermentation on grapes harvested in 2003 from two growing areas. Grapes from the 2004 harvest were tested at different ripeness using only oenotannins exhibiting the best wine color stabilization in 2003. The response of different oenotannins varied according to grape characteristics, with gallnut and grape seed tannins most reliably stabilizing and increasing color intensity even after six months of storage. The same tannins positively affected wine color stabilization, an effect further enhanced in wine produced from less ripe grapes. Timing of oenotannin addition and grape characteristics had a significant effect on color intensity and stabilization. The estimation of grape phenolic maturity may allow for improved wine color characteristics by tailoring the use of oenotannins.

Rapid extraction and determination of phenols in extra virgin olive oil

Abstract Solid Phase Extraction (SPE) was utilised as an alternative technique for the rapid recovery of the phenolic fraction from virgin olive oil. Different kind of sorbent materials (C 18 , CN and Florisil) were tested and the validity of the SPE methodology was tested against two commonly utilised phenol extraction techniques. Statistical analysis of the analytical data showed that SPE can represent a reliable alternative to the traditional procedures. SPE with CN columns was also utilised as an enrichment technique for the HPLC analysis of the phenolic fraction in 12 virgin olive oils coming from Greece, Italy and Spain. Eleven unidentified peaks were found to be always present in the chromatograms of the 12 oils. The relationships between these peaks and the total phenol content, the oil oxidative stability and some of the perceived properties of the virgin olive oil flavour ( bitter and astringent ) were statistically evaluated.

In vivo effect of Chianti red wine on tissue factor, tissue factor pathway inhibitor and homocysteine levels.

In vivo effect of Chianti redwine on Tissue Factor, Tissue Factor Pathway Inhibitor and Homocysteine levels -

A Multivariate Methodological Approach to Relate Wine to Characteristics of Grape Composition: The Case of Typicality

Typicality is defined as the characteristics of a Protected Designation of Origin (PDO) wine related to a terroir. In the context of a PDO, a typicality assessment can be used to assess the global quality of a PDO wine. This study used a two-phase method to identify the distinctive characteristics of a PDO wine and then apply those findings to a case study of Chianti Montespertoli DOCG wine, where DOCG is the Italian acronym for PDO. A panel of wine professionals evaluated the typicality of a series of selected PDO wine samples, and a partial least squares (PLS) regression model was used to associate wine typicality and chemical composition. The model was used to predict wine typicality from the chemical composition of experimental wines (2009, 2010, and 2011 vintages) produced from grapes growing in the PDO area. Finally, regression coefficients of the PLS model were analyzed to select which grape chemical parameters were significant in describing the typicality of the wine. These highlight the most important factors to manage during winemaking to ensure the typicality of this wine.