VIEW ARTICLE DOI: 10.1094/ASBCJ-60-0122
Effect of Reduction of Carbonyl Compounds by Yeast on Flavor Stability of Happoshu. Chikako Shimizu (1), Masao Ohno, Shigeki Araki, Shigeki Furusho, Junji Watari, and Masachika Takashio, Brewing Research Laboratories, Sapporo Breweries, Ltd., 10 Okatohme, Yaizu, Shizuoka, 425-0013 Japan. (1) Corresponding author. Phone: 054-629-7983; Fax: 054-629-3144; E-mail: <Chikako.Shimizu@sapporobeer.co.jp> J. Am. Soc. Brew. Chem. 60(3):122-129, 2002. Accepted February 12, 2002.
In Japan, beverages with higher than ~67% malt are considered beer. Those with lower are called Happoshu, although the malt ratio in most Happoshu brands is below 25%. Organoleptic tests on aged Happoshu were performed, and the amounts of carbonyl compounds were determined using gas chromatography, HPLC, and liquid chromatography-mass spectrometry. These results led to the selection of 3-methylbutanal as one of the most decisive indices for flavor staleness, which appears as a caramel-like or papery flavor in Happoshu. The brewing trials suggested that the suspended yeast cell concentration at the end of primary fermentation is a decisive factor for the reduction of 3-methylbutanal, as well as the reduction of yeast cell activity. Yeast strains that were preferable for beer “conventional” brewing were not always suitable for Happoshu fermentation. The fermentation progress was found to be particularly important in stabilizing the flavor of Happoshu. One of the mechanisms proposed is that the yeast plays an important role in decreasing the amount of staling compounds and their precursors. Keywords: Beer, Cell concentration, Dicarbonyl, Low malt ratio, 3-Methylbutanal
Efectos
de Reducción
de Componentes
Carbonilos por
Levadura en
la Estabilidad
de Sabor de
Happoshu.
En Japón, las bebidas con mas de 67% de malta se consideran cerveza. Esas con menos se llaman Happoshu, aunque la proporcion en casi todas las marcas de Happoshu es menos de 25%. Se desempeñaron pruebas organolépticas en Happoshu añejado, y las cantidades de componentes carbonilos se determinaron utilizando cromatografía de gases, HPLC, y cromatografía de liquido-espectrometría de masas. Estos resultados conducieron a la selección de 3-methylbutanal como uno de los índices más decisivo de sabor añejado, que aparece como tipo caramelo o a sabor de papel en Happoshu. Las elaboraciones de estas pruebas sugieren que las concentraciónes de células de levadura al final de la primera fermentación son factores decisivos en la reducción de 3-methylbutanal, tal como la reducción de la actividad de las células de levadura. Cepas de levadura que son preferibles para la elaboración “convencional” de cerveza no siempre son convenientes para la fermentación de Happoshu. Uno de los mecanismos que se propone es que la levadura desempeña un papel importante en desminuir la cantidad de componentes añejos y sus precursores. Palabras claves: Cerveza, Concentración de células, Dicarbonilo, Tasa baja de malta, 3-Methylbutanal