Use of hydrodistillation and headspace solid-phase microextraction to characterize the volatile composition of different hop cultivars

Authors

  • Laura Vázquez-Araújo,

    Corresponding author
    1. Laboratory of Agro-food Biotechnology, CITI-University of Vigo, Tecnópole-Tecnological Park of Galicia, San Cibrao das Viñas, Ourense, Spain
    • Chemical Engineering Department, Faculty of Sciences, University of Vigo (Campus Ourense), Ourense, Spain
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  • Raquel Rodríguez-Solana,

    1. Chemical Engineering Department, Faculty of Sciences, University of Vigo (Campus Ourense), Ourense, Spain
    2. Laboratory of Agro-food Biotechnology, CITI-University of Vigo, Tecnópole-Tecnological Park of Galicia, San Cibrao das Viñas, Ourense, Spain
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  • Sandra M Cortés-Diéguez,

    1. Chemical Engineering Department, Faculty of Sciences, University of Vigo (Campus Ourense), Ourense, Spain
    2. Laboratory of Agro-food Biotechnology, CITI-University of Vigo, Tecnópole-Tecnological Park of Galicia, San Cibrao das Viñas, Ourense, Spain
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  • José M. Domínguez

    1. Chemical Engineering Department, Faculty of Sciences, University of Vigo (Campus Ourense), Ourense, Spain
    2. Laboratory of Agro-food Biotechnology, CITI-University of Vigo, Tecnópole-Tecnological Park of Galicia, San Cibrao das Viñas, Ourense, Spain
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Correspondence to: Laura Vázquez-Araújo, Chemical Engineering Department, Faculty of Sciences, University of Vigo (Campus Ourense), As Lagoas s/n, 32004 Ourense, Spain. E-mail: lvazquezara@uvigo.es

Abstract

Background

Hop cones, the immature inflorescences of the female plant of Humulus lupulus L., have been used for centuries to improve the flavor of beer and can be also used for a great variety of other products. Four samples of hop, belonging to three different cultivars (Nugget, Saaz and Perle), were studied in the present work. Headspace solid-phase microextraction and hydrodistillation techniques were used to obtain the volatile profiles of the samples.

Results

Independent of the technique employed, over 40 volatile compounds were detected in the hop pellet samples (esters, monoterpenes, monoterpenoids, sesquiterpenes and sesquiterpenoids). Sesquiterpenes and sesquiterpenoids represented the majority of the total aromatic compounds. The main compounds for all cultivars were myrcene, β-caryophyllene and humulene, but the presence of high amounts of β-farnesene in Saaz cultivar was highlighted.

Conclusion

Both techniques were suitable for studying qualitatively the volatile composition of hop pellets, but some differences were shown when studying the proportion of the main constituents of the volatile profiles. Understanding these differences may help researchers design future studies to advise the industry how to exploit the potential of each hop cultivar. © 2013 Society of Chemical Industry

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