Fac-simile Scheda Linee di Ricerca - Federalimentare

Dati pubblicati inerenti il tema di ricerca:1. Andrich G., Zinnai A., Venturi F., Fiorentini R. (2005). A tentative model to describe theevolution of phenolic compounds durino the maceration of Sangiovese and Merlot grapes. It.J. Food Sci., 17, 45 – 58.The maceration of the solid parts (dregs) of grapes is a fundamental step of wine-making not only for the productionof of high quality red wines but also of structured white wines characterised by a high content of aromaticcompounds. A mathematical modle able to describe the time evolution of the phenolic fractions during grapemaceration is reported and discussed. While the accumulation of total phenols and catechins in the must/wineduring grape maceration can be described by the mass transfer equation introduced by Fick to evaluate the thediffusion occurring between two heterogeneous phases, a more complex mathematical approach is introduced todetermine the time evolution of anthocyanins. The extraction rate of different phenolic compounds, does notseem to vary significantly with the kind of fermentor or the wine-making technology used, but both the yield andthe chemical composition of the extracts appear to be significantly affected by extraction time.2. Andrich. G., Venturi F., Andreotti A., Zinnai A. (2008). Evolution of different phenolic compoundsduring prefermentative criomaceration of Sangiovese grapes. Proceedings of the ThirdInternational Conference on Sangiovese, Florence, December 3-8, 2008.To put in evidence the effect induced by cryogen addition on extraction rates and yields of different phenolic fractionsas a function of winemaking technologies adopted, two amounts of the same Sangiovese grapes has beentransformed using the same working conditions but for one of these the pre-fermentative cold maceration inducedby the addition of solid carbon dioxide has been used.To have a significant measure of ability shown by different phenolic fractions to diffuse in the liquid phase, a kineticparameter (maximum extractability) has been identified. Anthocyanins put in evidence the higher value ofextractability (35.0 % of extract for day), but surprising their ability to diffuse in the liquid phase is not so deeplydifferent from that (30.5) shown by catechins (tannins of low molecular weight). The increased concentration ofanthocynins in the product obtained by cryomaceration, make the end wines more coloured and this may be duenot only to a more efficient extraction but also to the protecting effect of gaseous CO 2 which stays on must/wineand avoids its possible interaction with oxygen of air.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.it380