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WineEast What's New in Research Enological Research in the East Scientists find yeast-assimilable nitrogen differs between vinifera and hybrid cultivars By Andrew G. Reynolds S everal universities in the eastern and Midwestern United States and Canada have active and productive enology programs. By far the largest is Cornell University, which has Food Science, Horticulture and Plant Pathology/Entomology departments on two campuses (in Geneva and Ithaca, N.Y.) in addition to research facilities in western New York state, the Hudson Valley and Long Island. Other noteworthy research programs include those at Pennsylvania State University, Virginia Polytechnic Institute and State University, Ohio State University, Michigan State University, Purdue University and Brock University in Ontario, Canada. Many eastern programs are carrying out enology research, specifically Dr. Gavin Sacks and his colleagues in Geneva, who are studying odoractive compounds; additionally, two programs (Geneva and Purdue) are looking into yeast-assimilable nitrogen (YAN) concentrations in grapes throughout the East. The descriptions below are based upon edited authors' abstracts from meetings of ASEV-Eastern Section. Odor-active compounds Characterization of odor-active compounds in grapes and wines produced from non-Vitis vinifera species important to grape breeding. WineEast HIGHLIGHTS: • oxy aromas associated with Vitis labrusca grapes were not F detected in V. riperia or V. cinerea wines. Most odorants were derived from fermentation. • ust treatment with silicone before fermentation resulted M in the reduction of herbaceous aromas caused by methoxypyrazines in the final wine. • In one study, hybrid cultivars showed higher residual yeast assimilable nitrogen than V. vinifera. Such differences should impact fermentation-management strategies. Many jurisdictions in the East are almost exclusively growing Vitis vinifera, but New York and some other areas depend on hybrid varieties for wine production as well. The breeding program in Geneva has a long tradition in the introduction of high-quality hybrid grapes such as Cayuga White (1972), Chardonel (1990), Traminette (1996) and most recently Corot Noir and Noiret (2006). N O N N O Isobutylmethoxypyrazine Isopropylmethoxypyrazine Methoxypyrazine compounds were found in Corot Noir and Noiret wines (Qun Sun et al., ASEV-ES 2011). Under the direction of Dr. Gavin Sacks, the enology program at Geneva has concentrated on odor-active compounds in non-vinifera cultivars and species. Qun Sun et al. (ASEV-ES 2011) focused upon non-vinifera species and produced wines from V. riparia, cinerea and vinifera under identical conditions. Volatiles were extracted from wines by solid-phase-microextraction, and 40 potent odorants determined by quantitative gas chromatography olfactometry (GC/O), with the majority subsequently identified by GC-mass spectrometry (GC-MS). The key odorants previously associated with foxy aromas in V. labrusca grapes, methyl anthranilate and 2-aminoacetophenone were not detected in the V. riparia or cinerea wines by either GC/O or GC-MS. Most odorants (24 of 40) were fermentation-derived (i.e., fatty acid ethyl esters) and did not differ by more than a factor of two in flavor dilution (FD) value. Several grape-derived odorants with vegetative and earthy aromas were at higher FD (> 4 factor of difference) in the non-vinifera wines: 92 W in es & V i ne s APR I L 2 013 Che mblink N