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3) Zocca F., Lomolino G., Spettoli P., Lante A. (2008) A study on the relationship between thevolatile composition of Moscato and Prosecco Grappa and enzymatic activities involved in itsproduction, Journal of the Institute Of Brewing, 114(3), , 262-269.The enzymatic transformations during storage of pomaces greatly affect the composition of Italian Grappa. Thisstudy examines the impact of pectin methylesterase (PME), β-glucosidase (βG) and esterases (ESTs) on thecomposition of Moscato and Prosecco Grappa. Grape pomaces were fermented for differing periods of time. Afterprotein extraction, the enzymatic activities were detected by spectrophotometric and electrophoretic methods.To determine by gas chromatography the evolution of methanol, terpenes, ethyl acetate and lactate in pomacesand Grappa samples, distillations by Cazenave equipmentand a traditional copper alambic were performed. Sensorialevaluation was carried out. There is a close relationship between the PME activity of grape pomaces, thedegree of pectin methylation, and the concentration of methanol before distillation. The results obtained suggestthat inhibition of grape pomaces PME may be adopted to control methanol concentration. The glycosidases ofgrape and/or yeast seem to have a limited effect on the release of volatile compounds from glycosides located ingrape skins. As regards the contribution of grape and microorganism esterase, several hypotheses are discussed.4) Zocca F., Lomolino G., Lante A. (2008) 3,4-Dihydroxyphenylalanine gel diffusion assay forpolyphenol oxidase quantification, Analytical Biochemistry, 383, , 335-336.We have developed a simple, inexpensive plate assay to detect and quantify polyphenol oxidase(PPO) activity from different origins. The logarithm of enzyme activity is linearly correlatedwith the diameter of the dark, L-3,4-dihydroxyphenylalanine (L-DOPA) oxidized circlesproduced in the gel, thereby allowing quantification of PPO. Moreover, precision and high reproducibilityof the assay were confirmed by statistical analysis.5) Lante A., Zocca F., Spettoli P., Lomolino G., Bellicampi D., Raiola A., Lionetti V. Uso di uninibitore proteico della pectinmetilesterasi per la riduzione della formazione di metanolo inmosti di uva e vinacce e processo per la stessa, Titolare del brevetto: Università di Padova,Numero della domanda: PD2007A000065, Data di deposito: 28/02/2007. EstensionePCT/EP2008/052347Following thorough research the inventors have now demonstrated that the pectinmethylesterase inhibitor obtainedfrom kiwi or obtained by recombinant technologyis also active against pectin methylesterase from grapeand marc and is able to effectively inhibit methanol formation in grape must and marc.The present inventiontherefore relates to the use of a pectin methylesterase inhibitor or a part thereof having pectin methylesterase inhibitoractivity for reducing methanol formation in grape must and marc and in products derived therefrom byfermentation and distillation. Preferably the pectin methylesterase inhibitor is from Actinidia chinensis and isobtainedby kiwi purification or by recombinant technology. The invention also relates to a process for reducingmethanol formation in grape must and marc and in products derived therefrom based on the use of the PME inhibitorfrom Actinidia chinensis or a part thereof having pectin methylesterase inhibitor activity, obtained by kiwipurification or by recombinant DNA methods.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.it310