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The possibility of having an easy to determine maturity index able to estimate the extractability of phenol compoundswith sufficient reliability, can be a valuable tool for the enological community.2. Letaief H., Rolle L., Zeppa G., Gerbi V. (2008) - Assessment of grape skin hardness by apuncture test. J. Sci. Food Agric., 88, 1567-1575.The release of grape components during winemaking might be related to the mechanical properties of the skin, inparticular its hardness. Samples from three varieties collected during the 2005 vintage season in Piedmont, Italywere tested for their skin hardness using a texture analyzer. The goal was to understand the statistical interactionsbetween three factors, variety, cluster position, and puncture point and their influence on the grape skin hardness.A discussion on the relationship between the size of the sample used and the confidence level is also provided.Results of the ANOVA test showed that there is an interaction between the variety and the puncture point whenmeasuring the skin hardness with the break energy. The position of the berry on the cluster does not affect theberry skin break energy; we also show that a sample size depend on the variety tested. The break energy is moreuseful in understanding the effect of the three factors on the skin hardness. Other factors that might affect thepuncture test applied to grapes need to be studied in the future and the usefulness of the test in winemaking willneed to be further developed.3. Río Segade S., Rolle L., Gerbi V., Orriols I. (2008) - Phenolic ripeness assessment of grapeskin by texture analysis. J. Food Comp. Anal., 21, 644-649.The elaboration of high quality red wines requires the assessment of grape phenolic maturity by thedetermination of phenolic compounds concentration and their extractability during winemaking process. Themain aim of this work was to ascertain whether simple texture parameters, like the grape skin hardness andthickness, account for phenolic maturity of berry skin. Furthermore, the function of these grape mechanicalproperties in the differentiation of 13 grapevine varieties from Galicia (North-West of Spain) was studied duringboth 2005 and 2006 vintages. An Universal Testing Machine TAxT2i Texture Analyzer was used to carry out thetexture test. Total anthocyanin concentration varied from 191 to 2660 mg kg -1 fresh berry weight, whileextractable anthocyanin concentration ranged from 116 to 1453 mg kg -1 fresh berry weight, respectively found inMerenzao and Loureira Tinta varieties. A significant regression was found between anthocyanin extractability,berry skin break force and thickness. Berry skin break force and energy represent meaningful variables forvarietal characterization and differentiation. The toughest berry skin corresponded to the Sousón variety, whileMouratón cultivar indeed was the weakest berry skin.4. Letaief H., Rolle L., Gerbi V. (2008) - Mechanical behavior of winegrapes under compressiontests. Am. J. Enol. Vitic., 59, 3, 323-329.This work focuses on the grape texture analysis of seven grapevine varieties at ripeness, Barbera, Brachetto,Cabernet sauvignon, Dolcetto, Freisa, Nebbiolo and Pinot noir, collected during the 2004 and 2005 vintageseasons in Piedmont, N-W Italy. Different compression tests are applied on the whole berry, the skin and seedand different mechanical indices are estimated. Univariate and multivariate statistical analysis are applied todifferentiate the grape varieties and to determine the main sources of variability present in the data sets. It isshown that the texture indices in the grape characterization depend on the variety and also on the harvest season.Moreover, texture profile analysis (TPA) is the most useful test for grape differentiation.5. Rolle L., Guidoni S. (2007) - Color and anthocyanin evaluation of red winegrapes by CIE L*,a*, b* parameters. J. Int. Sci. Vigne Vin., 41, 4, 193-201.The aim of this work was to study the color of the wine grapes using the CIELAB parameters and to develop colorimetricindexes which can be used as a rapid method to assess the anthocyanin content of the wine grapes inthe vineyard. L*, a*, b* parameters were measured by a reflectance spectrophotometer on eighteen red winegrapesat harvest. Two indexes were calculated: CIRG2, used as colorimetric index for table grapes and CIRWG(Color Index for Red Wine Grapes). These indexes showed effective potentialities for descriptive, taxonomic andampelografic studies. Particularly the CIRWG index is more correlated to the total anthocyanin amount, whilethe CIRG2 is more correlated to the different forms of the anthocyanins. The colorimetric indexes applied directlyin the vineyard permit to assess the total anthocyanin content and to give further quickly information on grapequality and maturity. The development of analytical methods for the evaluation of anthocyanin immediates, easilyapplicable at low cost in the field by grape-growers and winemakers, can be very useful in deciding the harvestdate.SISTAL - SOCIETA’ ITALIANA DI SCIENZE E TECNOLOGIE ALIMENTARIDipartimento di Scienze e Tecnologie Agroalimentari, Università degli Studi della TusciaVia San Camillo de Lellis, 01100 ViterboTel.: 0761- 35 74 94/7 , Fax: 0761- 35 74 98, e-mail: mmoresi@unitus.it452