1,720,986 research outputs found
Esempio di progettazione del curricolo di un corso di laurea di primo livello in Viticoltura ed Enologia
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Rapid Determination of Phenol Content in Extra Virgin Olive Oil
No full textA quick extraction methodology was developed to reduce the time usually required to determine the phenol cntent in olive oil. The validity of this method, based on SPE technique, was tested against two other phenole xtraction techniques. The statistical analysis of the analytical data showed that over a phenol content range of 110-550 ug/g oil the proposed method can be a reliable alternative for a rapid extraction of the phenols from olive oil
Grapevine performances in five area of Chianti Classico
Full text linkThe research was carried out in the ‘Chianti Classico’ area and it was part of the ‘Chianti Classico 2000’ research project. The performances ‘Sangiovese’ grapevine (clone ‘SSF-A548’) grafted on ‘1103P’ and ‘420A’ rootstocks, were evaluated during a six years period, on five experimental vineyards located in the Province of Florence and Siena. The vineyards were established at a density of 3500 plants per hectare, trained to horizontal spur cordon (m 0.7 from the ground) with 30000 buds per hectare. The main meteorological data were monitored by automatic stations and soil analysis was performed at the beginning of the trials. Vines were planted in a randomized block design with four or five replication according to the vineyard size and uniformity. During six consecutive years on 30 plants from each thesis were carried out the following observations: phenology earliness (budbreak, veraison), bud fertility, bunch weight, and yield and pruning weight per plant, must characteristics of the berries at harvest. Physical and chemical analysis of wines obtained from microvinification (made in 500 L containers), were also performed. The climatic differences resulted among the zones of the ‘Chianti Classico’ examined, had a significant effect on vine phenology also in relationship with altitude, which together to soil characteristics contributed to affect the agronomic behaviour of the three varieties, the must composition and the wine characteristics. Discriminant analysis allowed distinguishing some sites, whose differences can be ascribed to the territorial influence on the vegetative and productive activity of the grapevine, berry ripening and wine composition. Hierarchical influences due to clone ‘SSF-A548’ according to the site and year are presented
Caratterizzazione di un formaggio commerciabile attraverso la definizione del suo profilo sensoriale: l'esempio del Grana Padano.
No full textA methodological approach for characterisation, through the sensory profile, of a standardised product, like the Grana Padano cheese, has been reported. Quantitative Descriptive Analysis was applied by a trained panel of 7 judges to samples of known origin having different ripening times. Generalised Procustes Analysis was utilised to describe the sensory differences between cheeses; in particular the flavour by mouth "milk", "bouillon cube" and "dry mushrooms" resulted typical of Grana Padano at the suitable ripening level. Spider plots reporting the sensory profile of the samples at different ripening times were built on the basis of the sensory attributes selected by the panellists. The sensory profile of Grana Padano aged 15 months (the minimum time required for commercialisation of this product) was utilised as a reference standard and compared with the sensory characteristics of the Grana Padano samples having different ripening time
Approccio metodologico per la caratterizzazione di un formaggio commerciabile attraverso la definizione del suo profilo sensoriale: l'esempio del Grana Padano.
No full textPrediction of perceived astringency induced by phenolic compounds II: Criteria for panel selection and preliminary application on wine samples
No full textIn the following work, subject saliva characteristics affecting panel astringency evaluation in phenolic mixtures were studied. Sixty subjects were selected on the basis of their salivary flow, haze developing capacity and protein concentration. Subjects rated the perceived astringency of tannic acid (TA), commercial procyanidin (PA) and grape seed extract (GSE) solutions with concentration values ranging from 0.42 to 1.4 g/L. Astringency intensity perception proved to be inversely related to saliva flow rate and haze developing capacity. No significant correlations were found between saliva protein concentration and intensity of astringency perception. A panel selected on the basis of subject similarity for flow rate and haze developing capacity rated the astringency intensity of set sample training solutions of TA, PA and GSE with concentrations ranging from 0.39 to 4.48 g/L. The reactivity of the same astringent solutions with mucin was measured in an in vitro assay and expressed in terms of Nephelometric Turbidity Units (NTU). Three predictive models described by a linear regression of astringency intensity vs. NTU were found. The possibility of a practical application of the proposed assay for optimization of wine production was evaluated on 18 experimental wines. A linear correlation was found between the intensity astringency ratings of wine samples and the in vitro assay response. © 2005 Elsevier Ltd. All rights reserved
Prediction of perceived astringency induced by phenolic compounds
No full textA method which can be used to estimate perceived astringency due to polyphenolic compounds is presented here. Thirty subjects were selected on the basis of them having similar salivary flows and they were trained to rate the perceived astringency of tannic acid and grape seed extract solutions. A scale of phenolic compound concentrations ranging from 0 to 3.2 g/L was selected in order to obtain an experimental curve describing the perceived intensity of the sensation. The same astringent solutions were added to a mucin solution in conditions resembling those present in the oral cavity. The formation of polyphenol-protein complexes was measured on the basis of the increasing turbidity of the reaction mixture and was expressed in terms of nephelometric turbidity units (NTU). Experimental curves describing NTU vs polyphenol concentration were obtained. Predictive models of astringency intensity vs NTU were produced. The predictive capacity of the models was checked by comparing the measured and predicted intensities of a set of samples prepared at phenolic compound concentration level varying from 0.94 to 2.13 g/L. © 2004 Elsevier Ltd. All rights reserved
Rapid Extraction and Determination of Phenols in Extra Virgin Olive Oil
No full textSolid 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 (C18, 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
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