i. Title: The potential aroma and flavor compounds in Vitis sp. cv. Koshu and V. vinifera L. cv. Chardonnay under different environmental conditions ii. Running title: Potential aroma and flavor compounds in non-aromatic wine grape cultivars under different environmental conditions iii. Sharon Marie Bahena-Garrido1, Tomoko Ohama1, Yuka Suehiro2, Yuko Hata1, Atsuko Isogai1, Kazuhiro Iwashita1, Nami Goto-Yamamoto1 and Kazuya Koyama1 iv.v. ABSTRACT BACKGROUND: Koshu, a hybrid of Vitis vinifera L. and V. davidii Foex, is the most popular indigenous cultivar for wine production in Japan. However, little is known about the potential aroma compounds it contains and how environmental factors affect these. In this study, we obtained comprehensive profiles of the volatile (both glycosidically bound and free) and phenolic compounds that occur in Koshu berries, and compared these with similar profiles for V. vinifera cv. Chardonnay. We then compared the response of these two cultivars to bunch shading and the ripening-related phytohormone abscisic acid (ABA). RESULTS:Koshu berries contained significantly higher concentrations of phenolic compounds, hydroxycinnamic acid derivatives, and some volatile phenols, such as 4-vinyl guaiacol and eugenol, than Chardonnay berries, which are thought to contribute to the characteristics of Koshu wine. In addition, Koshu berries had a distinctly different terpenoid composition from Chardonnay berries. Shading reduced the concentrations of norisoprenoid in both cultivars, as well as several phenolic compounds particularly their volatile derivatives in Koshu. The exogenous application of ABA induced ripening and increased the concentrations of lipid derivatives, such ashexanol, octanol, nonanol, and 1-octen-3-ol. Linear discriminant analysis showed that the aromatic potential could be discriminated clearly based on cultivar, bunch shading, and ABA application. CONCLUSION:The unique secondary metabolite profiles of Koshu and their different responses to environmental factors could be valuable for developing various styles of Koshu wines and new cultivars with improved quality and cultural characteristics.

BACKGROUND Koshu, a hybrid of Vitis vinifera L. and V. davidii Foex, is the most popular indigenous cultivar for wine production in Japan. However, little is known about the potential aroma compounds it contains and how environmental factors affect these. In this study, we obtained comprehensive profiles of the volatile (both glycosidically bound and free) and phenolic compounds that occur in koshu berries, and compared these with similar profiles for V. vinifera cv. chardonnay. We then compared the response of these two cultivars to bunch shading and the ripening‐related phytohormone abscisic acid (ABA). RESULTS Koshu berries contained significantly higher concentrations of phenolic compounds, such as hydroxycinnamic acid derivatives, and some volatile phenols, such as 4‐vinyl guaiacol and eugenol, than chardonnay berries, which are thought to contribute to the characteristics of koshu wine. In addition, koshu berries had a distinctly different terpenoid composition from chardonnay berries. Shading reduced the concentration of norisoprenoid in both cultivars, as well as several phenolic compounds, particularly their volatile derivatives in koshu berries. The exogenous application of ABA induced ripening and increased the concentrations of lipid derivatives, such as hexanol, octanol, 1‐nonanol, and 1‐octen‐3‐ol. Multivariate and discriminant analyses showed that the potential aroma and flavor compounds in the berries could be discriminated clearly based on cultivar and environmental cues, such as light exposure. CONCLUSION The unique secondary metabolite profiles of koshu and their different responses to environmental factors could be valuable for developing various types of koshu wines and new cultivars with improved quality and cultural characteristics. © 2018 Society of Chemical Industry

In sake brewing, the steamed rice is used in 2 ways, added to sake-mash and making rice-koji. Rice-koji is made from the steamed rice by using koji starter, and its quality is an important determinant of the aroma/taste of sake. The sake rice Koshitanrei (KOS) was developed in Niigata Prefecture by crossing 2 sake rice varieties, Gohyakumangoku and Yamadanishiki. Recently, we reported the characteristic components/metabolites in sake made from KOS by conducting metabolome analysis using UPLC-QTOF-MS. In this study, to investigate the effect of koji starter and sake rice cultivars on the sake metabolites, we performed small-scale sake-making tests using the above 3 rice cultivars and 3 koji starters. Finally, we demonstrated that some of the characteristic components/metabolites of sake from KOS are affected by the koji starter. Thus, in addition to rice cultivar, koji starter plays an important role for establishment/maintenance of the quality of the final product.

In sake brewing, the steamed rice is used in two ways, added to sake-mash (as kake-mai) and making koji. The rice is an important determinant for the quality of sake, as the metabolites in sake affect its taste/aroma. The sake rice Koshitanrei (KOS) was developed in Niigata Prefecture by genetically crossing two sake rice, Gohyakumangoku and Yamadanishiki. However, the metabolites in sake from KOS have not been analyzed. Here, to investigate the characteristic metabolites in sake from KOS, we performed two types of small-scale sake-fermentation tests changing only the rice used for kake-mai or total rice (both kake-mai and koji) by these three rice cultivars and examined the effect of KOS on sake metabolites by the metabolome analysis method using UPLC-QTOF-MS. We identified the peaks/metabolites, whose intensity in sake from KOS was higher/lower than those from the other cultivars. The brewing properties of KOS were partially characterized by this analysis.

No abstract