Mechanical behavior of winegrapes under compression tests.

Grape texture analyses were performed at ripeness on seven grapevine varieties (Barbera, Brachetto, Cabernet Sauvignon, Dolcetto, Freisa, Nebbiolo, and Pinot noir) collected during the 2004 and 2005 seasons in Piedmont, northwestern Italy. Different compression tests were applied on whole berry, skin, and seed and mechanical indices were estimated. Univariate and multivariate statistical analysis were applied to differentiate the varieties and to determine the main sources of variability present in the data sets. The texture indices in the grape characterization depended on variety and harvest season. Moreover, texture profile analysis (TPA) was the most appropriate test for grape differentiation.