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Characterization of the Chinese SA-1 Hop (Humulus lupulus L.) Variety

MBAA TQ vol. 43, no. 2, 2006, pp. 136-138  |  VIEW ARTICLE

Yumei Liu (1,2), Yangming Liu (1), Lipin Wang (1), Jian Tang (1), and Kuifang Liu (2). 1. Key Laboratory of Food Science and Safety, Ministry of Education, Southern Yangtze University, Wuxi, 214036, Jiangsu, China. 2. College of Chemistry and Chemical Engineering, Xinjiang University, Urmuqi, 830046, Xinjiang, China.

Abstract
In this study, the content of hop resins, hop bitter acids, hop polyphenols, and hop fragrance volatiles in Chinese ‘SA-1’ hops was analyzed. The aromatic hop fragrance volatiles in dried hop cones and the liquid CO(2) hop extract were analyzed by using headspace solid-phase microextraction fixed with gas chromatography/mass spectrometry (GC/MS). The hop oils were analyzed by using GC/MS. The research focused on comparing the change in quality parameters of ‘SA-1’ during processing and storage. It was shown that the SA-1 variety had a low content of alpha-bitter acids at 3.40% (w/w), while the content of beta-bitter acids was 3.50% (w/w) and the cohumulone ratio was 23.92% rel. The composition of hop volatiles in fresh ‘SA-1’ hops and its product was characterized by the beta-farnesene content, which was in the range of 11 to 15% rel., and the trans-alpha-bergamotene content, which was about 1% rel. However, after 10 months of storage at about 20°C, these compounds were present in only trace amounts. In contrast, a certain volatile fatty acid plus ester and the oxides of terpene were formed during hop aging. The results obtained suggest that the Chinese SA-1 hop variety is a fine aroma hops.

Keywords: hop oil, hop resin, SA-1 hop variety, storage

 

Síntesis
Se estudió el contenido de resinas de lúpulo, ácidos amargos del lúpulo, polifenoles del lúpulo y volátiles aromáticos del lúpulo, en lúpulo ‘SA-1’ chino. Los volátiles aromáticos del lúpulo en conos secos de lúpulo y en el extracto CO(2) de lúpulo fueron analizados utilizando microextracción de fase sólida en el espacio gaseoso (“head space”) fijado con cromatografía de gases/ espectrometría de masa (GC/MS). Los aceites de lúpulo se analizaron por GC/MS. Se concentró la investigación en la comparación del cambio en los parámetros de calidad de ‘SA-1’ durante el procesamiento y almacenaje. Se demostró que la variedad SA-1 tiene un bajo contenido de alfa-ácidos (3,4% p/p) junto con un contenido de beta-ácidos de 3,5% (p/p) y una proporción relativa de 23,92% de cohumulonas. La composición de volátiles del lúpulo ‘SA-1’ fresco y sus productos se caracteriza por su contenido de beta-farnesene con una proporción de 11–15% relativo, y su contenido relativo de trans-alfa-bergamotene cerca de 1%. Sin embargo, estos componentes sólo se encontraban como trazas después de 10 meses de almacenamiento a 20°C. A diferencia de esto, se formaron óxidos de terpene y un cierto ácido graso volátil durante el envejecimiento del lúpulo. Los resultados sugieren que el lúpulo chino SA-1 es un fino lúpulo aromático.

Palabras claves: aceite de lúpulo, resina de lúpulo, variedad de lúpulo SA-1, almacenamiento

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